Merge pull request 'release v1.13.0: payments wallet mechanics + database point-in-time recovery' (#220) from development into master

The S3 endpoint is a host only; some providers publish a separate, non-443
port. Add an optional PGBACKREST_S3_PORT (default 443) alongside the endpoint
host, wired through the prod overlay, write-prod-env.sh and both prod workflows,
and clarify in the docs that the endpoint variable takes the host alone.

.claude/skills/deploy-check/SKILL.md

@@ -0,0 +1,89 @@
+---
+name: deploy-check
+description: "Use before any deploy-touching change to this repo — phrases like '/deploy-check', 'is this prod-safe', 'before we deploy', 'deploy safety review', 'проверь перед деплоем', 'это безопасно для прода'. Runs a pre-deploy checklist of this project's hard-won runtime constraints against the current diff, so the crash classes that have bitten live environments get caught before shipping instead of after."
+---
+
+# Pre-deploy runtime-constraint check
+
+Triggered before shipping anything that touches the deploy contour (Dockerfiles,
+`deploy/`, Caddyfile, compose, migrations, boot guards, the Telegram side-service,
+edge config). The worst frictions in this repo were never logic bugs — they were
+**environment mismatches that crashed a live env and forced a redesign**. Run this
+list against the diff first; turn crash-and-redesign into a single pass.
+
+This checklist is a prompt, **not** the source of truth. The canonical detail
+lives in `deploy/README.md`, `docs/ARCHITECTURE.md`, `docs/EDGE_HTTP3.md`, and the
+agent memory files referenced below — read them when an item is in play, and add a
+new class here when a new incident teaches one.
+
+## How to run it
+
+1. `git diff <base>...HEAD --stat` to see what the change actually touches.
+2. For every risk class below that the diff touches, perform the **Check** and
+   report PASS / FAIL with the exact file:line to fix. Skip classes the diff does
+   not touch — say which you skipped and why.
+3. Remember: **deploy-job green ≠ healthy**. CI's deploy probe has historically
+   passed with a dead backend (it only checked static landing+gateway). Verify the
+   real feature live (`/readyz`, the actual flow) after deploy, not just the green.
+
+## Risk classes
+
+### 1. Container user — distroless nonroot UID 65532
+- **Bit us:** TLS keys `chmod 600` for the host owner crash-looped gateway + bot at
+  boot with "permission denied" — service images run UID 65532.
+- **Check:** any new/changed mounted secret, key, or config file must be readable by
+  UID 65532 (`0644`, not `0600`). Scan the diff for file modes, `chmod`, and new
+  volume mounts. (memory: `distroless-nonroot-mounted-secrets`)
+
+### 2. Caddy header pipeline ordering
+- **Bit us:** `header_up delete` after `set` nulled the value (the honeypot tag went
+  empty); it passed CI and only showed up live.
+- **Check:** in any Caddyfile change, verify the `set` / `delete` / `header_up`
+  ordering for every affected route, and test the tripwire/route on the live
+  contour, not just CI.
+
+### 3. Edge Alt-Svc / HTTP3
+- **Bit us:** edge advertised `Alt-Svc: h3` while UDP/443 was never exposed
+  (docker tcp-only + ufw tcp-only); clients cached it 30 days and stalled on dead
+  QUIC before falling back to h2 — Mini App "hangs on load".
+- **Check:** any edge/caddy change keeps `Alt-Svc: clear` (or only advertises h3 if
+  UDP/443 is genuinely exposed). (memory: `tg-app-load-stall-dead-http3-altsvc`,
+  `docs/EDGE_HTTP3.md`)
+
+### 4. Prod caddy config recreate
+- **Bit us:** prod rolling deploy did **not** recreate caddy on a config-only change
+  (pinned `caddy:2-alpine` + `admin off`), so a new Caddyfile deployed GREEN but
+  stayed inert until a manual `docker restart`.
+- **Check:** a config-only edge change must `--force-recreate` caddy in
+  `prod-deploy.sh` `roll()`; never trust deploy-green for edge config.
+  (memory: `prod-deploy-caddy-config-recreate`)
+
+### 5. DICT_VERSION / dictionary boot
+- **Bit us:** an early `DICT_VERSION` refuse-boot guard was wrong and crashed the
+  live env when bumped on a seeded volume; it had to be redesigned to "marker-wins".
+- **Check:** any change touching `DICT_VERSION`, dict load, or the boot guard must
+  keep marker-wins semantics and survive a seeded volume **and** an image rollback.
+  `DICT_VERSION` is a required build-arg (no default), single-sourced. A new dict
+  goes live via the admin console upload, not a redeploy. (memory:
+  `dict-version-deploy-verify`, `contour-schema-change-wipe`)
+
+### 6. Migrations — expand-contract + rollback safety
+- **Bit us / risk:** a non-backward-compatible migration breaks image rollback (DB
+  ahead of rolled-back code).
+- **Check:** migrations must be **expand-contract** (backward-compatible). A schema
+  change adds the maintenance window + a consistent `pg_dump` in prod-deploy. On the
+  **test contour**, a schema/wire-label change needs `DROP SCHEMA backend CASCADE` +
+  backend restart (new code vs old persisted DB), else the contour breaks. (memory:
+  `contour-schema-change-wipe`)
+
+### 7. Telegram permission model
+- **Bit us:** permissions are an **AND-intersection** — default-allow with explicit
+  denies, not default-deny; inverting it broke access.
+- **Check:** any change to the Telegram permission / relay logic preserves the
+  AND-intersection default-allow shape. (memory: `telegram-forum-relay-gotchas`)
+
+## Output
+
+A short PASS/FAIL table over the classes the diff touches, each FAIL with the exact
+file:line and the fix. If every touched class passes, say so plainly and name the
+post-deploy live check to run (not just "CI green").

.claude/vk-games-integration.md

@@ -0,0 +1,175 @@
+# VK Mini App / VK Games — integration reference
+
+Captured research + our implementation map, so a future session does not need to re-fetch
+the VK docs. Authoritative external source: <https://dev.vk.com/> (the `dev.vk.com` portal
+does not render via plain HTTP fetch; the facts below were cross-checked against the VKCOM
+reference repos cited at the end and verified against our own Go implementation).
+
+A VK **game** is technically a **VK Mini App**: an HTML5 SPA VK loads in an **iframe inside
+vk.com** (desktop + mobile web) and in a **WebView** inside the VK mobile apps (iOS/Android).
+We serve our existing SPA under a dedicated `/vk/` path, mirroring the Telegram `/telegram/`
+entry — the single-origin, path-routed model.
+
+## 1. Embedding model
+
+- VK loads the app at the **Web iframe URL** configured in the app settings (HTTPS + valid
+  cert required), appending the signed launch parameters as the **URL query string**.
+- An optional separate **Mobile iframe URL** is used by the VK mobile apps (we use the same).
+- No special `X-Frame-Options` / CSP `frame-ancestors` is required from us — VK frames the
+  configured origin. (Our edge sets **no** framing headers today, so VK works as-is; see the
+  clickjacking note in §Security.)
+- URL must match the settings exactly (scheme, host, no stray `www`/whitespace).
+
+## 2. Launch parameters (URL query)
+
+VK appends these to the iframe `src`. The `vk_*` set is what the signature covers.
+
+| Param | Meaning |
+| --- | --- |
+| `vk_user_id` | signed-in VK user numeric id — **the identity** |
+| `vk_app_id` | our registered app id |
+| `vk_is_app_user` | 0/1 — user authorized/installed the app |
+| `vk_are_notifications_enabled` | 0/1 |
+| `vk_language` | 2-letter UI language (`ru`, `en`, …) |
+| `vk_platform` | `mobile_iphone` \| `mobile_android` \| `mobile_web` \| `desktop_web` \| … |
+| `vk_ts` | unix seconds when VK generated the params |
+| `vk_ref` | where the app was opened from (`catalog`, `feed`, …) |
+| `vk_access_token_settings` | comma-separated granted scopes (often empty) |
+| `vk_group_id`, `vk_viewer_group_role`, `vk_is_favorite`, `vk_client` | optional/contextual |
+| `sign` | **the signature** (see §3) — NOT part of the signed set |
+
+Always present: `vk_user_id`, `vk_app_id`, `vk_platform`, `vk_ts`, `sign`.
+
+The user's **name is NOT in the launch params** (only `vk_user_id`). Read it client-side via
+`VKWebAppGetUserInfo` (see §4) — unsigned, so treat it as a cosmetic display seed only.
+
+## 3. Signature verification (`sign`)  — CONFIRMED base64url, not hex
+
+Algorithm (verified against our `gateway/internal/vkauth` + an independent Python reference):
+
+1. Collect the query params whose key starts with `vk_` (exclude `sign`).
+2. Sort by key (alphabetical).
+3. Serialize as a URL-encoded query string `k=v&k=v…` (Go `url.Values.Encode()` matches VK's
+   reference serialization for the constrained launch-param charset).
+4. `HMAC-SHA256(serialized, secret)` where `secret` = the app's **«Защищённый ключ»**
+   (protected / secure key, a.k.a. client_secret) from the app settings.
+5. **base64url, no padding** (`+`→`-`, `/`→`_`, strip `=`).
+6. Constant-time compare against `sign`.
+
+VK launch params have **no built-in expiry** (unlike Telegram's `auth_date`). We do NOT enforce
+freshness — the minted server session is the short-lived credential; a replay only
+re-authenticates the same `vk_user_id`.
+
+Verified against the official doc <https://dev.vk.com/ru/mini-apps/development/launch-params-sign>
+(prose + PHP example: base64url = `strtr('+/','-_')` + `rtrim('=')`) and reproduced identically by
+independent Node `crypto` + Python references. **Doc-example caveat**: that page shows secret
+`wvl68m4dR1UpLrVRli` → sign `exTIBP…`, but the secret is a **placeholder** — recomputing with it does
+NOT yield the shown sign (it was made with the real, unshown key). Don't chase the mismatch; our
+`vkauth.Verify` is correct (`gateway/internal/vkauth/vkauth_test.go` carries cross-checked vectors,
+incl. the `%2C` comma case for `vk_access_token_settings`).
+
+## 4. VK Bridge (client SDK)
+
+`@vkontakte/vk-bridge` (npm, v3.x; bundled — `default` export `bridge`). Methods we use / may use:
+
+- `VKWebAppInit` — **required**: tells VK the Mini App loaded (dismisses VK's loading cover).
+- `VKWebAppGetUserInfo` — `{ id, first_name, last_name, photo_200, … }`; no extra scope needed.
+- `VKWebAppGetLaunchParams` — parsed `vk_*` **without** `sign` (so NOT usable for our server
+  verification — read `window.location.search` instead, which carries `sign`).
+- `VKWebAppGetAuthToken` — OAuth access token for VK API calls (only if we ever call VK API).
+- `VKWebAppShare` — native share dialog (the friend-code invite uses it; `navigator.share` is absent
+  in the desktop VK iframe). **Used.**
+- `VKWebAppCopyText` — clipboard copy that works inside the VK iframe, where `navigator.clipboard` is
+  blocked. **Used** as the copy-code / copy-link path.
+- `VKWebAppUpdateConfig` (subscribe) — light/dark scheme; the app follows it while the theme pref is
+  "auto" (the VK webview's prefers-color-scheme does not track it). **Used.**
+- `VKWebAppSetViewSettings` / `VKWebAppSetSwipeSettings` — viewport / swipe-back (mobile); not used.
+- `VKWebAppUpdateInsets` (+ `VKWebAppUpdateConfig`) — device safe-area insets; the app **max'es** them
+  with CSS `env(safe-area-inset-*)` (viewport-fit=cover) so the bottom home bar is cleared. The bridge
+  value is needed on Android, where the VK webview exposes no `env()` inset. **Used.**
+
+The bridge talks to the embedding VK client over postMessage; it is NOT an external fetch, so
+it has no telegram.org-style load-hang risk. The SDK reads browser globals at import — we import
+it **lazily** so the pure URL helpers stay node-test-importable.
+
+**Deep links — NOT possible on VK (confirmed on the contour).** The VK iframe receives ONLY the signed
+`vk_*` launch params (+ `sign`); VK strips any custom data from the app link. The documented
+`vk.com/app<id>#<payload>` form is eaten by the vk.com SPA (which owns the URL hash), and a
+`vk.com/app<id>?hash=<payload>` query is dropped (the diagnostic showed `rawSearch` with only `vk_*`
+and an empty `hash`). So the friend-code invite link is just `vk.com/app<id>` (`vkShareLink`, app id
+from `vk_app_id`); the recipient enters the **copied code by hand** (`VKWebAppCopyText` works). The
+`vkStartParam` reader + the `bootVK` routing stay as a no-op today, ready if a post-moderation VK
+channel (e.g. an invite API) ever delivers a payload.
+
+## 5. Test mode (to verify before moderation)
+
+1. App already registered (we have the App ID).
+2. In the app settings (dev.vk.com / `vk.com/editapp?act=settings&app_id=<id>`):
+   - Category = **Игра** (Game).
+   - **Web iframe URL** = our public HTTPS `/vk/` (the test-contour origin for contour testing,
+     prod `https://erudit-game.ru/vk/` later). Mobile iframe URL = same.
+   - Copy the **«Защищённый ключ»** → set as `GATEWAY_VK_APP_SECRET` (Gitea `TEST_`/`PROD_` secret).
+   - Add own VK id to **testers**; open in test mode.
+3. Test mode = visible only to admins/testers, no payments processed.
+
+## 6. Auth / identity (our model)
+
+- `vk_user_id` (from verified params) → backend identity `kind='vk'`, `external_id=vk_user_id`,
+  auto-confirmed (a platform identity). First contact seeds language from `vk_language` and the
+  display name from the client-supplied `VKWebAppGetUserInfo` name (placeholder if empty).
+- No VK access token / VK API call needed for the launch+login MVP.
+
+## 7. Payments / monetization
+
+VK Pay / «голоса» (votes) are **optional**, not required to publish a free game. Not planned.
+
+## 8. ToS / moderation (pre-publish, analyzed — no blocker for a free «Эрудит»)
+
+- **Trademark**: "Scrabble" is trademarked. Our public brand is **«Эрудит»** (erudit-game.ru),
+  a generic Russian word-game name → fine. Ensure the VK-registered app name is «Эрудит»/word-game,
+  NOT "Scrabble". The repo name is internal and irrelevant to moderation.
+- **Pre-publish requirements**: public **Privacy Policy** + **ToS** URLs (disclose collected data:
+  `vk_user_id`, language; mention VK), **age rating** (likely 6+/12+), icon, description.
+- **Dictionary**: standard word lists; VK may expect offensive-word filtering — likely fine for a
+  dictionary game, flag if moderation asks.
+- **In-game chat (UGC)**: we already have a moderated chat + support relay → covered.
+- Moderation reviews after submission (commonly ~24–72h); rejects on violence/hate/sexual/illegal
+  content or IP infringement — none apply.
+
+## 9. Platforms
+
+Desktop web (iframe), mobile web (iframe), VK iOS app (WKWebView), VK Android app (WebView). Bridge
+methods behave per-platform; the app's own back chevron + app-shell document-pin cover navigation
+without VK-specific code. Theme/viewport fine-tuning is best verified live in the real VK client
+(not reproducible in Playwright — like the iOS gesture caveats).
+
+## 10. Our implementation map (what to touch for VK)
+
+- **Wire**: `pkg/fbs/scrabble.fbs` → `VKLoginRequest{ params, browser_tz, display_name }`
+  (regen: `make -C pkg fbs` + `pnpm -C ui codegen`).
+- **Gateway**: `internal/vkauth/` (the §3 verify), `internal/transcode` op `auth.vk`
+  (registered via `WithVKAuth(secret)` option; `DomainCode` → `invalid_vk_params`),
+  `internal/backendclient` `VKAuth` → `POST /api/v1/internal/sessions/vk`,
+  config `GATEWAY_VK_APP_SECRET`, SPA mount `/vk/` in `internal/connectsrv/server.go`.
+- **Backend**: `internal/account` `KindVK` + `ProvisionVK`/`vkSeed` + `confirmed` for platform
+  kinds; `internal/server/handlers_auth.go` `handleVKAuth` + route; migration
+  `00005_vk_identity.sql` (widen `identities_kind_chk` to include `'vk'`, expand-contract).
+- **UI**: `src/lib/vk.ts` (`onVKPath`/`vkLaunchParams`/`insideVK`/`vkInit`/`vkUserName` plus `vkAppId`/
+  `vkStartParam`/`vkShare`/`vkCopyText`/`vkOnScheme`), `app.svelte.ts` `bootVK` (+ deep-link routing
+  and VK scheme→theme) + the `/vk/` dispatch branch + shared `retryMiniAppBoot`, `codec.ts`
+  `encodeVKLogin`, `transport.ts`/`client.ts`/`mock/client.ts` `authVK`, `deeplink.ts` `vkShareLink`,
+  `Friends.svelte` (VK share/copy), `app.css` `--tg-safe-*` defaulting to `env(safe-area-inset-*)`.
+- **Edge/deploy**: `deploy/caddy/Caddyfile` `/vk` path; `GATEWAY_VK_APP_SECRET` in
+  `docker-compose.yml` + `.env.example` + `ci.yaml` (`TEST_…` secret) + `prod-deploy.yaml`
+  (`PROD_…` secret, deploy-main).
+- **Deferred**: payments (VK Pay / votes), native (Capacitor) VK, account-linking a vk identity to an
+  existing account, VK push. (Done after the launch+auth MVP — Group B: native share + clipboard via
+  the bridge, the friend-code deep link, the auto-theme follow, and the home-bar safe area.)
+
+## Sources
+
+- VKCOM/vk-bridge — <https://github.com/VKCOM/vk-bridge>
+- VKCOM/vk-apps-launch-params (canonical signature examples) — <https://github.com/VKCOM/vk-apps-launch-params>
+- kravetsone/vk-launch-params — <https://github.com/kravetsone/vk-launch-params>
+- SevereCloud/vksdk `vkapps.ParamsVerify` (Go reference) — <https://pkg.go.dev/github.com/SevereCloud/vksdk/v2/vkapps>
+- VK Mini Apps API — <https://github.com/VKCOM/vk-mini-apps-api>

.gitea/workflows/ci.yaml

@@ -26,12 +26,12 @@ on:
   push:
     branches: [development]
 
-# The dictionary release the test suite validates against — the current
-# scrabble-dictionary release. Centralised here so a release bump is one edit; the
-# unit/integration jobs inherit it. The deploy job overrides it per contour with
-# vars.TEST_DICT_VERSION (the seed for a fresh volume), see deploy/README.md.
+# The dictionary release. One Gitea variable is the single source of truth: the
+# test suite validates against it here (inherited by the unit/integration jobs) and
+# both contours' deploy jobs seed a fresh volume with the same value. A release bump
+# is one edit (the variable). See deploy/README.md.
 env:
-  DICT_VERSION: v1.3.0
+  DICT_VERSION: ${{ vars.DICT_VERSION }}
 
 jobs:
   # changes detects which areas a PR/push touched, so the test jobs can skip when
@@ -73,6 +73,9 @@ jobs:
             go=false; ui=false
             if echo "$files" | grep -qE '^(backend/|pkg/|gateway/|platform/|loadtest/|go\.work)'; then go=true; fi
             if echo "$files" | grep -qE '^ui/'; then ui=true; fi
+            # The render sidecar bundles ui/src/lib, so its dir rides the ui lane (the
+            # deploy's compose build picks it up either way).
+            if echo "$files" | grep -qE '^renderer/'; then ui=true; fi
             # A workflow or deploy change re-runs everything as a safety net.
             if echo "$files" | grep -qE '^(\.gitea/workflows/|deploy/)'; then go=true; ui=true; fi
           else
@@ -199,19 +202,96 @@ jobs:
       - name: Bundle-size budget
         run: node scripts/bundle-size.mjs
 
+      # The render sidecar executes the shared ui/src/lib/gameimage.ts on skia-canvas;
+      # its smoke test guards the bundling + skia seam (docs/TESTING.md).
+      - name: Render sidecar test
+        working-directory: renderer
+        run: |
+          pnpm install --frozen-lockfile
+          pnpm test
+
       - name: Install Playwright browsers
         run: pnpm exec playwright install chromium webkit
         timeout-minutes: 5
 
+      # The offline e2e plays a real local vs_ai game, so it needs the per-variant dawgs; fetch the
+      # release the same way the Go jobs do and point the mock preview's copy step (scripts/
+      # e2e-dict.mjs, via E2E_DICT_DIR below) at it.
+      - name: Fetch dictionary DAWGs
+        run: |
+          mkdir -p "${GITHUB_WORKSPACE}/dawg"
+          curl -fsSL -o /tmp/dawg.tar.gz "https://gitea.iliadenisov.ru/developer/scrabble-dictionary/releases/download/${DICT_VERSION}/scrabble-dawg-${DICT_VERSION}.tar.gz"
+          tar xzf /tmp/dawg.tar.gz -C "${GITHUB_WORKSPACE}/dawg"
+          ls -la "${GITHUB_WORKSPACE}/dawg"
+
       - name: E2E smoke (mock)
         run: pnpm run test:e2e
         timeout-minutes: 5
+        env:
+          E2E_DICT_DIR: ${{ github.workspace }}/dawg
+
+  # conformance proves the client's local move preview (the ported dawg reader +
+  # validator, ui/src/lib/dict) byte-for-byte against the authoritative Go engine:
+  # a Go step generates golden parity vectors from the release dictionaries, then the
+  # gated Vitest suite replays them. It spans both toolchains, so it runs whenever the
+  # Go engine side or the UI side changed.
+  conformance:
+    needs: changes
+    if: ${{ needs.changes.outputs.go == 'true' || needs.changes.outputs.ui == 'true' }}
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        shell: bash
+    env:
+      GOPRIVATE: gitea.iliadenisov.ru/*
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Fetch dictionary DAWGs
+        run: |
+          mkdir -p "${GITHUB_WORKSPACE}/dawg"
+          curl -fsSL -o /tmp/dawg.tar.gz "https://gitea.iliadenisov.ru/developer/scrabble-dictionary/releases/download/${DICT_VERSION}/scrabble-dawg-${DICT_VERSION}.tar.gz"
+          tar xzf /tmp/dawg.tar.gz -C "${GITHUB_WORKSPACE}/dawg"
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.work
+          cache: true
+
+      - name: Generate golden parity vectors
+        run: |
+          go run ./backend/cmd/dictgen -dawg-dir "${GITHUB_WORKSPACE}/dawg" -out /tmp/dictgold
+          go run ./backend/cmd/validategen -dawg-dir "${GITHUB_WORKSPACE}/dawg" -out /tmp/validgold
+          go run ./backend/cmd/movegen -dawg-dir "${GITHUB_WORKSPACE}/dawg" -out "${GITHUB_WORKSPACE}/movegold"
+
+      - name: Set up Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+
+      - name: Install pnpm
+        run: npm install -g pnpm@11.0.9
+
+      - name: Install deps
+        working-directory: ui
+        run: pnpm install --frozen-lockfile
+
+      - name: Local-eval conformance (reader + validator vs the Go engine)
+        working-directory: ui
+        env:
+          DICT_DAWG_DIR: ${{ github.workspace }}/dawg
+          DICT_GOLD_DIR: /tmp/dictgold
+          DICT_VALID_DIR: /tmp/validgold
+          DICT_MOVEGEN_DIR: ${{ github.workspace }}/movegold
+        run: pnpm exec vitest run src/lib/dict/
 
   # gate is the single branch-protection required check. It always runs and passes
   # only when each upstream job succeeded or was skipped (a path-filtered no-op),
   # failing the merge if any actually failed or was cancelled.
   gate:
-    needs: [unit, integration, ui]
+    needs: [unit, integration, ui, conformance]
     if: always()
     runs-on: ubuntu-latest
     defaults:
@@ -221,7 +301,7 @@ jobs:
       - name: Aggregate required checks
         run: |
           fail=
-          for r in "unit:${{ needs.unit.result }}" "integration:${{ needs.integration.result }}" "ui:${{ needs.ui.result }}"; do
+          for r in "unit:${{ needs.unit.result }}" "integration:${{ needs.integration.result }}" "ui:${{ needs.ui.result }}" "conformance:${{ needs.conformance.result }}"; do
             name="${r%%:*}"; res="${r#*:}"
             echo "$name = $res"
             case "$res" in
@@ -236,9 +316,13 @@ jobs:
     # Auto test-deploy on a PR into development and on the push that merges it.
     # A PR into master is test-only (this job is skipped); prod deploy is manual.
     # Gates on `gate` (so a real test failure blocks the deploy) but runs even when
-    # some test jobs were path-skipped.
-    needs: [gate]
-    if: ${{ (github.event_name == 'push' && github.ref == 'refs/heads/development') || (github.event_name == 'pull_request' && github.base_ref == 'development') }}
+    # some test jobs were path-skipped. Skipped entirely when neither the Go nor the
+    # UI side changed (e.g. a docs-only change): the contour image is unchanged, so
+    # there is nothing to redeploy. `changes` still defaults both to true when the
+    # diff is uncomputable, and a workflow/deploy edit forces both true, so an
+    # ambiguous or infra change still deploys as a safety net.
+    needs: [changes, gate]
+    if: ${{ (needs.changes.outputs.go == 'true' || needs.changes.outputs.ui == 'true') && ((github.event_name == 'push' && github.ref == 'refs/heads/development') || (github.event_name == 'pull_request' && github.base_ref == 'development')) }}
     runs-on: ubuntu-latest
     defaults:
       run:
@@ -261,12 +345,47 @@ jobs:
           GRAFANA_ADMIN_PASSWORD: ${{ secrets.TEST_GRAFANA_ADMIN_PASSWORD }}
           TELEGRAM_BOT_TOKEN: ${{ secrets.TEST_TELEGRAM_BOT_TOKEN }}
           TELEGRAM_PROMO_BOT_TOKEN: ${{ secrets.TEST_TELEGRAM_PROMO_BOT_TOKEN }}
+          # VK Mini App protected key (offline HMAC for the launch-param signature); empty
+          # leaves the VK auth path (auth.vk) disabled until the operator sets the secret.
+          # One VK Mini App serves every contour -> unprefixed secret.
+          GATEWAY_VK_APP_SECRET: ${{ secrets.GATEWAY_VK_APP_SECRET }}
+          # VK ID web login (browser VK-identity linking): the VK ID "Web" app's protected key
+          # for the server-side confidential code exchange — a SEPARATE VK app from the Mini
+          # App above. One VK ID "Web" app serves every contour -> unprefixed secret.
+          GATEWAY_VK_ID_CLIENT_SECRET: ${{ secrets.GATEWAY_VK_ID_CLIENT_SECRET }}
+          # Planted honeytoken bearer: presenting it flags the caller (logs + a ban metric on
+          # test where the IP ban is off; a 24h IP ban on prod). Per-contour secret; empty = trap off.
+          GATEWAY_HONEYTOKEN: ${{ secrets.TEST_GATEWAY_HONEYTOKEN }}
+          # Signs the finished-game export download URLs (backend + compose interpolation).
+          EXPORT_SIGN_KEY: ${{ secrets.TEST_EXPORT_SIGN_KEY }}
+          # Transactional email via the shared Selectel relay: one account for every
+          # contour -> unprefixed host/port/tls/user/pass. Empty host leaves the backend
+          # on the log mailer (email disabled) but the contour still boots.
+          SMTP_RELAY_USER: ${{ secrets.SMTP_RELAY_USER }}
+          SMTP_RELAY_PASS: ${{ secrets.SMTP_RELAY_PASS }}
+          SMTP_RELAY_HOST: ${{ vars.SMTP_RELAY_HOST }}
+          SMTP_RELAY_PORT: ${{ vars.SMTP_RELAY_PORT }}
+          SMTP_RELAY_TLS: ${{ vars.SMTP_RELAY_TLS }}
+          SMTP_RELAY_FROM: ${{ vars.TEST_SMTP_RELAY_FROM }}
+          # Operator alerts: backend admin emails (new feedback / complaints) + Grafana
+          # infra alerts. Distinct senders + recipients; Grafana uses the relay's STARTTLS
+          # host:port. Empty leaves the alert worker off and Grafana SMTP disabled.
+          SMTP_RELAY_ADMIN_FROM: ${{ vars.TEST_SMTP_RELAY_ADMIN_FROM }}
+          ADMIN_EMAIL: ${{ vars.TEST_ADMIN_EMAIL }}
+          SMTP_RELAY_SERVICE_FROM: ${{ vars.TEST_SMTP_RELAY_SERVICE_FROM }}
+          SERVICE_EMAIL: ${{ vars.TEST_SERVICE_EMAIL }}
+          GRAFANA_SMTP_PORT: ${{ vars.GRAFANA_SMTP_PORT }}
+          GF_SMTP_ENABLED: ${{ vars.TEST_GF_SMTP_ENABLED }}
+          # Canonical public origin for links in the email (this contour's URL);
+          # required by the backend whenever SMTP_RELAY_HOST is set.
+          PUBLIC_BASE_URL: ${{ vars.TEST_PUBLIC_BASE_URL }}
           GM_BASICAUTH_USER: ${{ vars.TEST_GM_BASICAUTH_USER }}
-          GRAFANA_ROOT_URL: ${{ vars.TEST_GRAFANA_ROOT_URL }}
           CADDY_SITE_ADDRESS: ${{ vars.TEST_CADDY_SITE_ADDRESS }}
-          TELEGRAM_MINIAPP_URL: ${{ vars.TEST_TELEGRAM_MINIAPP_URL }}
+          # TELEGRAM_MINIAPP_URL, GRAFANA_ROOT_URL and VITE_VK_ID_REDIRECT_URL are derived
+          # from PUBLIC_BASE_URL in the run step below, not stored as their own variables.
           TELEGRAM_GAME_CHANNEL_ID: ${{ vars.TEST_TELEGRAM_GAME_CHANNEL_ID }}
           TELEGRAM_CHAT_ID: ${{ vars.TEST_TELEGRAM_CHAT_ID }}
+          TELEGRAM_SUPPORT_CHAT_ID: ${{ vars.TEST_TELEGRAM_SUPPORT_CHAT_ID }}
           TELEGRAM_BOT_USERNAME: ${{ vars.TEST_TELEGRAM_BOT_USERNAME }}
           # The promo button reuses the UI's Mini App link variable.
           TELEGRAM_BOT_LINK: ${{ vars.TEST_VITE_TELEGRAM_LINK }}
@@ -276,11 +395,16 @@ jobs:
           VITE_TELEGRAM_BOT_ID: ${{ vars.TEST_VITE_TELEGRAM_BOT_ID }}
           VITE_TELEGRAM_LINK: ${{ vars.TEST_VITE_TELEGRAM_LINK }}
           VITE_TELEGRAM_GAME_CHANNEL_NAME: ${{ vars.TEST_VITE_TELEGRAM_GAME_CHANNEL_NAME }}
-          VITE_GATEWAY_URL: ${{ vars.TEST_VITE_GATEWAY_URL }}
-          # Unset vars render empty -> the compose ":-" defaults apply.
+          # VK Mini App landing link + VK ID "Web" app id: one value each serves every
+          # contour -> unprefixed. VITE_VK_APP_ID also feeds the gateway (GATEWAY_VK_ID_APP_ID);
+          # the VK ID redirect URL is derived from PUBLIC_BASE_URL in the run step below.
+          VITE_VK_APP_LINK: ${{ vars.VITE_VK_APP_LINK }}
+          VITE_VK_APP_ID: ${{ vars.VITE_VK_APP_ID }}
+          # VITE_GATEWAY_URL omitted: the SPA is served same-origin, so it stays the
+          # compose ":-" empty default. Other unset vars likewise fall to their defaults.
           POSTGRES_DB: ${{ vars.TEST_POSTGRES_DB }}
           POSTGRES_USER: ${{ vars.TEST_POSTGRES_USER }}
-          DICT_VERSION: ${{ vars.TEST_DICT_VERSION }}
+          DICT_VERSION: ${{ vars.DICT_VERSION }}
           LOG_LEVEL: ${{ vars.TEST_LOG_LEVEL }}
         run: |
           # Seed the config files to a stable host path. The runner checks out into
@@ -291,8 +415,34 @@ jobs:
           conf="$HOME/.scrabble-deploy"
           rm -rf "$conf"
           mkdir -p "$conf"
-          cp -r caddy otelcol prometheus tempo grafana "$conf"/
+          cp -r caddy otelcol prometheus tempo grafana blackbox "$conf"/
           export SCRABBLE_CONFIG_DIR="$conf"
+          # Maintenance page for the redeploy window, mirroring prod-deploy.sh so the SPA
+          # overlay is exercised on the test contour too (not only prod). Raised just before
+          # the recreate and lowered once caddy is back (below); the trap clears it if the
+          # step fails so the contour never sticks in maintenance (and the reseed above wipes a
+          # stale flag anyway). The caddy-routed probes run in the NEXT step, after it is lowered.
+          maint_flag="$conf/caddy/on"
+          trap 'rm -f "$maint_flag"' EXIT
+          # Derive the public URLs from the one canonical origin instead of storing each as
+          # its own variable (paths are structural SPA routes / the Caddy /_gm sub-path).
+          # Exported before build so the VK ID redirect is baked into the SPA.
+          base="${PUBLIC_BASE_URL%/}"
+          export TELEGRAM_MINIAPP_URL="$base/telegram/"
+          export GRAFANA_ROOT_URL="$base/_gm/grafana/"
+          export VITE_VK_ID_REDIRECT_URL="$base/app/"
+          # Grafana's SMTP from_address must be a BARE address (it rejects the "Name" <addr>
+          # form the backend go-mail accepts) and validates it even when SMTP is disabled — a
+          # bad value crash-loops Grafana. Split the display-format SERVICE From into a bare
+          # address + name for Grafana; the backend keeps the full form.
+          svc_from="${SMTP_RELAY_SERVICE_FROM:-}"
+          case "$svc_from" in
+            *"<"*">"*)
+              export GRAFANA_SMTP_FROM_ADDRESS="$(printf '%s' "$svc_from" | sed -E 's/.*<([^>]+)>.*/\1/')"
+              export GRAFANA_SMTP_FROM_NAME="$(printf '%s' "$svc_from" | sed -E 's/[[:space:]]*<[^>]*>.*$//; s/^"//; s/"$//')" ;;
+            *)
+              export GRAFANA_SMTP_FROM_ADDRESS="$svc_from" ;;
+          esac
           # Bot-link mTLS material for the test contour: a private CA + gateway/bot
           # leaves (CN=gateway, the service name the bot dials). Prod supplies these
           # from PROD_ secrets instead. Regenerated each deploy; both ends redeploy
@@ -305,12 +455,23 @@ jobs:
           # bot on its own host instead (deploy/docker-compose.bot.yml), and the prod
           # main host omits both. Without the profile they would not start here.
           docker compose --ansi never --profile telegram-local build --progress plain
+          # Raise the maintenance page, THEN bring caddy onto the reseeded config mount so it
+          # actually carries the flag: the running caddy sits on the stale pre-reseed mount (the
+          # dir was rm'd + recreated — see the force-recreate note below), so a flag written to
+          # the new dir is invisible until caddy is recreated. With the fresh caddy up, an open
+          # SPA sees the 503 marker + overlay for the whole recreate window, not a bare reconnect.
+          : > "$maint_flag"
+          docker compose --ansi never up -d --force-recreate --no-deps caddy
           docker compose --ansi never --profile telegram-local up -d --remove-orphans
           # The config-only services bind-mount the reseeded config dir. A plain `up -d`
           # leaves them on the previous bind mount (the dir was rm'd + recreated), so a
-          # changed Caddyfile or Grafana dashboard is ignored — force-recreate them to
-          # pick up the fresh config.
-          docker compose --ansi never up -d --force-recreate --no-deps caddy otelcol prometheus tempo grafana
+          # changed Grafana dashboard is ignored — force-recreate them to pick up the fresh
+          # config. (Caddy was already recreated above so it would carry the maintenance flag.)
+          docker compose --ansi never up -d --force-recreate --no-deps otelcol prometheus tempo grafana
+          # Lower the maintenance page: services are back. An open SPA's poll now gets through
+          # (once the gateway finishes booting) and reloads into the fresh client; the caddy
+          # probes in the next step see 200. The EXIT trap is a backstop if we failed earlier.
+          rm -f "$maint_flag"
 
       - name: Probe the landing, gateway and backend
         run: |
@@ -336,6 +497,23 @@ jobs:
           docker logs --tail 50 scrabble-backend || true
           exit 1
 
+      - name: Probe the /dict edge route reaches the gateway
+        run: |
+          set -u
+          # The client fetches each game's dictionary blob at {edge}/dict/{variant}/{version}
+          # for the local move preview. If caddy does not route /dict to the gateway the request
+          # falls to the static landing and the client silently gets a non-dawg blob. Probed
+          # unauthenticated it must be the gateway's 401 (the route reaches the gateway), never a
+          # 404/200 from the landing catch-all.
+          out="$(docker run --rm --network edge alpine:3.20 wget -S -q -O /dev/null http://scrabble/dict/scrabble_en/v1 2>&1 || true)"
+          echo "$out" | grep -E "HTTP/" || true
+          if echo "$out" | grep -q " 401"; then
+            echo "ok: /dict reaches the gateway (401 unauthenticated)"
+          else
+            echo "FAIL: /dict did not reach the gateway (expected 401) — caddy route missing?"
+            exit 1
+          fi
+
       - name: Probe the Telegram validator and bot liveness
         run: |
           set -u

.gitea/workflows/prod-deploy.yaml

@@ -40,11 +40,22 @@ jobs:
       VITE_TELEGRAM_BOT_ID: ${{ vars.PROD_VITE_TELEGRAM_BOT_ID }}
       VITE_TELEGRAM_LINK: ${{ vars.PROD_VITE_TELEGRAM_LINK }}
       VITE_TELEGRAM_GAME_CHANNEL_NAME: ${{ vars.PROD_VITE_TELEGRAM_GAME_CHANNEL_NAME }}
-      VITE_GATEWAY_URL: ${{ vars.PROD_VITE_GATEWAY_URL }}
+      # VK Mini App link + VK ID "Web" app id: one value each serves every contour.
+      VITE_VK_APP_LINK: ${{ vars.VITE_VK_APP_LINK }}
+      VITE_VK_APP_ID: ${{ vars.VITE_VK_APP_ID }}
+      # VITE_GATEWAY_URL omitted: the SPA is served same-origin (compose ":-" default).
       POSTGRES_PASSWORD: ${{ secrets.PROD_POSTGRES_PASSWORD }}
       GM_BASICAUTH_HASH: ${{ secrets.PROD_GM_BASICAUTH_HASH }}
-      TELEGRAM_MINIAPP_URL: ${{ vars.PROD_TELEGRAM_MINIAPP_URL }}
-      DICT_VERSION: ${{ vars.PROD_DICT_VERSION }}
+      # `docker compose build` interpolates the WHOLE compose file, so every :?-guarded
+      # runtime var must be present at build even though it is not a build-arg — incl. the
+      # backend's EXPORT_SIGN_KEY (added with the finished-game export after v1.7.0, which is
+      # why the first v1.8.0 build tripped on it). POSTGRES_PASSWORD/GM_BASICAUTH_HASH above
+      # are here for the same reason; DICT_VERSION + the derived Mini App URL cover the rest.
+      EXPORT_SIGN_KEY: ${{ secrets.PROD_EXPORT_SIGN_KEY }}
+      # PUBLIC_BASE_URL drives the derived VK ID redirect (baked into the SPA) and the
+      # Mini App URL; both are computed in the build step, not stored variables.
+      PUBLIC_BASE_URL: ${{ vars.PROD_PUBLIC_BASE_URL }}
+      DICT_VERSION: ${{ vars.DICT_VERSION }}
     steps:
       - uses: actions/checkout@v4
         with:
@@ -58,10 +69,15 @@ jobs:
         working-directory: deploy
         run: |
           export TAG="${{ steps.ver.outputs.tag }}" APP_VERSION="${{ steps.ver.outputs.tag }}" SCRABBLE_CONFIG_DIR=.
-          # The four main-stack images via compose (reuses the build args, incl. VERSION);
+          # Derive the public URLs from the one canonical origin: the VK ID redirect is a
+          # build-arg baked into the SPA, and the Mini App URL satisfies the (profiled-out)
+          # bot service's compose ":?" guard during parse. See deploy/write-prod-env.sh.
+          base="${PUBLIC_BASE_URL%/}"
+          export VITE_VK_ID_REDIRECT_URL="$base/app/" TELEGRAM_MINIAPP_URL="$base/telegram/"
+          # The main-stack images via compose (reuses the build args, incl. VERSION);
           # the bot separately, since it is profiled out of the prod compose.
           docker compose -f docker-compose.yml -f docker-compose.prod.yml build
-          docker compose -f docker-compose.yml -f docker-compose.prod.yml push backend gateway landing validator
+          docker compose -f docker-compose.yml -f docker-compose.prod.yml push postgres backend gateway landing validator renderer
           docker build -f ../platform/telegram/Dockerfile --target bot --build-arg VERSION="$TAG" -t "$REGISTRY/scrabble-telegram-bot:$TAG" ..
           docker push "$REGISTRY/scrabble-telegram-bot:$TAG"
 
@@ -82,17 +98,57 @@ jobs:
       GM_BASICAUTH_HASH: ${{ secrets.PROD_GM_BASICAUTH_HASH }}
       GRAFANA_ADMIN_PASSWORD: ${{ secrets.PROD_GRAFANA_ADMIN_PASSWORD }}
       TELEGRAM_BOT_TOKEN: ${{ secrets.PROD_TELEGRAM_BOT_TOKEN }}
+      GATEWAY_VK_APP_SECRET: ${{ secrets.GATEWAY_VK_APP_SECRET }}
+      # VK ID web login: the "Web" app id (the gateway reuses it as GATEWAY_VK_ID_APP_ID at
+      # runtime) + the app's protected key. Both shared across contours. The redirect URL is
+      # derived from PUBLIC_BASE_URL in deploy/write-prod-env.sh.
+      VITE_VK_APP_ID: ${{ vars.VITE_VK_APP_ID }}
+      GATEWAY_VK_ID_CLIENT_SECRET: ${{ secrets.GATEWAY_VK_ID_CLIENT_SECRET }}
+      # Planted honeytoken bearer: presenting it earns a 24h IP ban + a high-severity alarm.
+      # Per-contour secret; empty = trap off. Rendered by deploy/write-prod-env.sh.
+      GATEWAY_HONEYTOKEN: ${{ secrets.PROD_GATEWAY_HONEYTOKEN }}
+      # Signs the finished-game export download URLs (backend BACKEND_EXPORT_SIGN_KEY).
+      EXPORT_SIGN_KEY: ${{ secrets.PROD_EXPORT_SIGN_KEY }}
+      # Transactional email via the shared Selectel relay (confirm-codes): one account for
+      # every contour -> unprefixed host/port/tls/user/pass.
+      SMTP_RELAY_USER: ${{ secrets.SMTP_RELAY_USER }}
+      SMTP_RELAY_PASS: ${{ secrets.SMTP_RELAY_PASS }}
+      SMTP_RELAY_HOST: ${{ vars.SMTP_RELAY_HOST }}
+      SMTP_RELAY_PORT: ${{ vars.SMTP_RELAY_PORT }}
+      SMTP_RELAY_TLS: ${{ vars.SMTP_RELAY_TLS }}
+      SMTP_RELAY_FROM: ${{ vars.PROD_SMTP_RELAY_FROM }}
+      # Operator alerts: backend admin emails + Grafana infra alerts (distinct senders +
+      # recipients; Grafana uses the relay's STARTTLS host:port).
+      SMTP_RELAY_ADMIN_FROM: ${{ vars.PROD_SMTP_RELAY_ADMIN_FROM }}
+      ADMIN_EMAIL: ${{ vars.PROD_ADMIN_EMAIL }}
+      SMTP_RELAY_SERVICE_FROM: ${{ vars.PROD_SMTP_RELAY_SERVICE_FROM }}
+      SERVICE_EMAIL: ${{ vars.PROD_SERVICE_EMAIL }}
+      GRAFANA_SMTP_PORT: ${{ vars.GRAFANA_SMTP_PORT }}
+      GF_SMTP_ENABLED: ${{ vars.PROD_GF_SMTP_ENABLED }}
+      PUBLIC_BASE_URL: ${{ vars.PROD_PUBLIC_BASE_URL }}
       PROD_BOTLINK_CA: ${{ secrets.PROD_BOTLINK_CA }}
       PROD_BOTLINK_GATEWAY_CERT: ${{ secrets.PROD_BOTLINK_GATEWAY_CERT }}
       PROD_BOTLINK_GATEWAY_KEY: ${{ secrets.PROD_BOTLINK_GATEWAY_KEY }}
       GM_BASICAUTH_USER: ${{ vars.PROD_GM_BASICAUTH_USER }}
-      GRAFANA_ROOT_URL: ${{ vars.PROD_GRAFANA_ROOT_URL }}
       CADDY_SITE_ADDRESS: ${{ vars.PROD_CADDY_SITE_ADDRESS }}
       LOG_LEVEL: ${{ vars.PROD_LOG_LEVEL }}
-      DICT_VERSION: ${{ vars.PROD_DICT_VERSION }}
+      DICT_VERSION: ${{ vars.DICT_VERSION }}
       POSTGRES_DB: ${{ vars.PROD_POSTGRES_DB }}
       POSTGRES_USER: ${{ vars.PROD_POSTGRES_USER }}
-      TELEGRAM_MINIAPP_URL: ${{ vars.PROD_TELEGRAM_MINIAPP_URL }}
+      # Point-in-time recovery (pgBackRest -> S3), prod main host only. Endpoint/bucket/
+      # region + the archive-mode switch are variables; the S3 keys + the repository cipher
+      # passphrase are secrets. All empty/off until the operator arms archiving; flipping
+      # PROD_PGBACKREST_ARCHIVE_MODE=on activates it (deploy/README.md, arming).
+      PGBACKREST_ARCHIVE_MODE: ${{ vars.PROD_PGBACKREST_ARCHIVE_MODE }}
+      PGBACKREST_S3_ENDPOINT: ${{ vars.PROD_PGBACKREST_S3_ENDPOINT }}
+      PGBACKREST_S3_PORT: ${{ vars.PROD_PGBACKREST_S3_PORT }}
+      PGBACKREST_S3_BUCKET: ${{ vars.PROD_PGBACKREST_S3_BUCKET }}
+      PGBACKREST_S3_REGION: ${{ vars.PROD_PGBACKREST_S3_REGION }}
+      PGBACKREST_S3_KEY: ${{ secrets.PROD_PGBACKREST_S3_KEY }}
+      PGBACKREST_S3_KEY_SECRET: ${{ secrets.PROD_PGBACKREST_S3_KEY_SECRET }}
+      PGBACKREST_CIPHER_PASS: ${{ secrets.PROD_PGBACKREST_CIPHER_PASS }}
+      # TELEGRAM_MINIAPP_URL and GRAFANA_ROOT_URL are derived from PUBLIC_BASE_URL in
+      # deploy/write-prod-env.sh, not stored variables.
     steps:
       - uses: actions/checkout@v4
         with:
@@ -120,24 +176,8 @@ jobs:
         run: |
           umask 077
           mkdir -p stage/certs-main
-          cat > stage/env.sh <<EOF
-          export REGISTRY='$REGISTRY'
-          export SCRABBLE_CONFIG_DIR='/opt/scrabble'
-          export POSTGRES_DB='${POSTGRES_DB:-scrabble}'
-          export POSTGRES_USER='${POSTGRES_USER:-scrabble}'
-          export POSTGRES_PASSWORD='$POSTGRES_PASSWORD'
-          export GM_BASICAUTH_USER='${GM_BASICAUTH_USER:-gm}'
-          export GM_BASICAUTH_HASH='$GM_BASICAUTH_HASH'
-          export GRAFANA_ADMIN_PASSWORD='$GRAFANA_ADMIN_PASSWORD'
-          export GRAFANA_ROOT_URL='$GRAFANA_ROOT_URL'
-          export CADDY_SITE_ADDRESS='$CADDY_SITE_ADDRESS'
-          export LOG_LEVEL='${LOG_LEVEL:-info}'
-          export DICT_VERSION='$DICT_VERSION'
-          export APP_VERSION='$TAG'
-          export TELEGRAM_BOT_TOKEN='$TELEGRAM_BOT_TOKEN'
-          export TELEGRAM_MINIAPP_URL='$TELEGRAM_MINIAPP_URL'
-          export GATEWAY_ABUSE_BAN_ENABLED='true'
-          EOF
+          # Shared with prod-rollback so the two paths render an identical runtime env.
+          APP_VERSION="$TAG" bash deploy/write-prod-env.sh stage/env.sh
           printf '%s\n' "$PROD_BOTLINK_CA"           > stage/certs-main/ca.crt
           printf '%s\n' "$PROD_BOTLINK_GATEWAY_CERT" > stage/certs-main/gateway.crt
           printf '%s\n' "$PROD_BOTLINK_GATEWAY_KEY"  > stage/certs-main/gateway.key
@@ -148,7 +188,7 @@ jobs:
           ssh_main 'mkdir -p /opt/scrabble/compose'
           tar -C deploy -czf - docker-compose.yml docker-compose.prod.yml prod-deploy.sh \
             | ssh_main 'tar -C /opt/scrabble/compose -xzf -'
-          tar -C deploy -czf - caddy otelcol prometheus tempo grafana \
+          tar -C deploy -czf - caddy otelcol prometheus tempo grafana blackbox \
             | ssh_main 'tar -C /opt/scrabble -xzf -'
           tar -C stage -czf - certs-main \
             | ssh_main 'rm -rf /opt/scrabble/certs && mkdir -p /opt/scrabble/certs && tar -C /opt/scrabble/certs --strip-components=1 -xzf -'
@@ -176,9 +216,11 @@ jobs:
       PROD_BOTLINK_BOT_CERT: ${{ secrets.PROD_BOTLINK_BOT_CERT }}
       PROD_BOTLINK_BOT_KEY: ${{ secrets.PROD_BOTLINK_BOT_KEY }}
       LOG_LEVEL: ${{ vars.PROD_LOG_LEVEL }}
-      TELEGRAM_MINIAPP_URL: ${{ vars.PROD_TELEGRAM_MINIAPP_URL }}
+      # PUBLIC_BASE_URL drives the derived Mini App URL in deploy/write-prod-bot-env.sh.
+      PUBLIC_BASE_URL: ${{ vars.PROD_PUBLIC_BASE_URL }}
       TELEGRAM_GAME_CHANNEL_ID: ${{ vars.PROD_TELEGRAM_GAME_CHANNEL_ID }}
       TELEGRAM_CHAT_ID: ${{ vars.PROD_TELEGRAM_CHAT_ID }}
+      TELEGRAM_SUPPORT_CHAT_ID: ${{ vars.PROD_TELEGRAM_SUPPORT_CHAT_ID }}
       TELEGRAM_BOT_USERNAME: ${{ vars.PROD_TELEGRAM_BOT_USERNAME }}
       TELEGRAM_BOT_LINK: ${{ vars.PROD_VITE_TELEGRAM_LINK }}
     steps:
@@ -192,19 +234,8 @@ jobs:
         run: |
           umask 077
           mkdir -p stage/certs-bot
-          cat > stage/env.bot.sh <<EOF
-          export SCRABBLE_CONFIG_DIR='/opt/scrabble'
-          export BOT_IMAGE='$REGISTRY/scrabble-telegram-bot:$TAG'
-          export BOTLINK_GATEWAY_ADDR='$MAIN_HOST:9443'
-          export TELEGRAM_BOT_TOKEN='$TELEGRAM_BOT_TOKEN'
-          export TELEGRAM_MINIAPP_URL='$TELEGRAM_MINIAPP_URL'
-          export TELEGRAM_GAME_CHANNEL_ID='$TELEGRAM_GAME_CHANNEL_ID'
-          export TELEGRAM_CHAT_ID='$TELEGRAM_CHAT_ID'
-          export TELEGRAM_PROMO_BOT_TOKEN='$TELEGRAM_PROMO_BOT_TOKEN'
-          export TELEGRAM_BOT_USERNAME='$TELEGRAM_BOT_USERNAME'
-          export TELEGRAM_BOT_LINK='$TELEGRAM_BOT_LINK'
-          export LOG_LEVEL='${LOG_LEVEL:-info}'
-          EOF
+          # Shared with prod-rollback so the two paths render an identical bot env.
+          BOT_IMAGE="$REGISTRY/scrabble-telegram-bot:$TAG" bash deploy/write-prod-bot-env.sh stage/env.bot.sh
           printf '%s\n' "$PROD_BOTLINK_CA"       > stage/certs-bot/ca.crt
           printf '%s\n' "$PROD_BOTLINK_BOT_CERT" > stage/certs-bot/bot.crt
           printf '%s\n' "$PROD_BOTLINK_BOT_KEY"  > stage/certs-bot/bot.key

.gitea/workflows/prod-rollback.yaml

@@ -51,13 +51,42 @@ jobs:
       PROD_BOTLINK_GATEWAY_CERT: ${{ secrets.PROD_BOTLINK_GATEWAY_CERT }}
       PROD_BOTLINK_GATEWAY_KEY: ${{ secrets.PROD_BOTLINK_GATEWAY_KEY }}
       GM_BASICAUTH_USER: ${{ vars.PROD_GM_BASICAUTH_USER }}
-      GRAFANA_ROOT_URL: ${{ vars.PROD_GRAFANA_ROOT_URL }}
       CADDY_SITE_ADDRESS: ${{ vars.PROD_CADDY_SITE_ADDRESS }}
       LOG_LEVEL: ${{ vars.PROD_LOG_LEVEL }}
-      DICT_VERSION: ${{ vars.PROD_DICT_VERSION }}
+      DICT_VERSION: ${{ vars.DICT_VERSION }}
       POSTGRES_DB: ${{ vars.PROD_POSTGRES_DB }}
       POSTGRES_USER: ${{ vars.PROD_POSTGRES_USER }}
-      TELEGRAM_MINIAPP_URL: ${{ vars.PROD_TELEGRAM_MINIAPP_URL }}
+      PUBLIC_BASE_URL: ${{ vars.PROD_PUBLIC_BASE_URL }}
+      # Full runtime env — parity with prod-deploy's deploy-main so a rollback re-renders
+      # the SAME env.sh (email / VK login / Grafana alerts survive a rollback). TELEGRAM_MINIAPP_URL
+      # and GRAFANA_ROOT_URL are derived from PUBLIC_BASE_URL in deploy/write-prod-env.sh.
+      GATEWAY_VK_APP_SECRET: ${{ secrets.GATEWAY_VK_APP_SECRET }}
+      VITE_VK_APP_ID: ${{ vars.VITE_VK_APP_ID }}
+      GATEWAY_VK_ID_CLIENT_SECRET: ${{ secrets.GATEWAY_VK_ID_CLIENT_SECRET }}
+      GATEWAY_HONEYTOKEN: ${{ secrets.PROD_GATEWAY_HONEYTOKEN }}
+      EXPORT_SIGN_KEY: ${{ secrets.PROD_EXPORT_SIGN_KEY }}
+      SMTP_RELAY_USER: ${{ secrets.SMTP_RELAY_USER }}
+      SMTP_RELAY_PASS: ${{ secrets.SMTP_RELAY_PASS }}
+      SMTP_RELAY_HOST: ${{ vars.SMTP_RELAY_HOST }}
+      SMTP_RELAY_PORT: ${{ vars.SMTP_RELAY_PORT }}
+      SMTP_RELAY_TLS: ${{ vars.SMTP_RELAY_TLS }}
+      SMTP_RELAY_FROM: ${{ vars.PROD_SMTP_RELAY_FROM }}
+      SMTP_RELAY_ADMIN_FROM: ${{ vars.PROD_SMTP_RELAY_ADMIN_FROM }}
+      ADMIN_EMAIL: ${{ vars.PROD_ADMIN_EMAIL }}
+      SMTP_RELAY_SERVICE_FROM: ${{ vars.PROD_SMTP_RELAY_SERVICE_FROM }}
+      SERVICE_EMAIL: ${{ vars.PROD_SERVICE_EMAIL }}
+      GRAFANA_SMTP_PORT: ${{ vars.GRAFANA_SMTP_PORT }}
+      GF_SMTP_ENABLED: ${{ vars.PROD_GF_SMTP_ENABLED }}
+      # PITR archiving parity: a rollback must re-render the SAME env.sh, else it would
+      # silently disarm WAL archiving (PGBACKREST_ARCHIVE_MODE would fall back to off).
+      PGBACKREST_ARCHIVE_MODE: ${{ vars.PROD_PGBACKREST_ARCHIVE_MODE }}
+      PGBACKREST_S3_ENDPOINT: ${{ vars.PROD_PGBACKREST_S3_ENDPOINT }}
+      PGBACKREST_S3_PORT: ${{ vars.PROD_PGBACKREST_S3_PORT }}
+      PGBACKREST_S3_BUCKET: ${{ vars.PROD_PGBACKREST_S3_BUCKET }}
+      PGBACKREST_S3_REGION: ${{ vars.PROD_PGBACKREST_S3_REGION }}
+      PGBACKREST_S3_KEY: ${{ secrets.PROD_PGBACKREST_S3_KEY }}
+      PGBACKREST_S3_KEY_SECRET: ${{ secrets.PROD_PGBACKREST_S3_KEY_SECRET }}
+      PGBACKREST_CIPHER_PASS: ${{ secrets.PROD_PGBACKREST_CIPHER_PASS }}
       INPUT_TARGET: ${{ inputs.target_version }}
     steps:
       - uses: actions/checkout@v4
@@ -89,24 +118,9 @@ jobs:
         run: |
           umask 077
           mkdir -p stage/certs-main
-          cat > stage/env.sh <<EOF
-          export REGISTRY='$REGISTRY'
-          export SCRABBLE_CONFIG_DIR='/opt/scrabble'
-          export POSTGRES_DB='${POSTGRES_DB:-scrabble}'
-          export POSTGRES_USER='${POSTGRES_USER:-scrabble}'
-          export POSTGRES_PASSWORD='$POSTGRES_PASSWORD'
-          export GM_BASICAUTH_USER='${GM_BASICAUTH_USER:-gm}'
-          export GM_BASICAUTH_HASH='$GM_BASICAUTH_HASH'
-          export GRAFANA_ADMIN_PASSWORD='$GRAFANA_ADMIN_PASSWORD'
-          export GRAFANA_ROOT_URL='$GRAFANA_ROOT_URL'
-          export CADDY_SITE_ADDRESS='$CADDY_SITE_ADDRESS'
-          export LOG_LEVEL='${LOG_LEVEL:-info}'
-          export DICT_VERSION='$DICT_VERSION'
-          export APP_VERSION='$TARGET'
-          export TELEGRAM_BOT_TOKEN='$TELEGRAM_BOT_TOKEN'
-          export TELEGRAM_MINIAPP_URL='$TELEGRAM_MINIAPP_URL'
-          export GATEWAY_ABUSE_BAN_ENABLED='true'
-          EOF
+          # Same writer as prod-deploy's deploy-main -> the rollback re-renders the FULL
+          # runtime env (not a subset), so email / VK login / Grafana alerts survive it.
+          APP_VERSION="$TARGET" bash deploy/write-prod-env.sh stage/env.sh
           printf '%s\n' "$PROD_BOTLINK_CA"           > stage/certs-main/ca.crt
           printf '%s\n' "$PROD_BOTLINK_GATEWAY_CERT" > stage/certs-main/gateway.crt
           printf '%s\n' "$PROD_BOTLINK_GATEWAY_KEY"  > stage/certs-main/gateway.key
@@ -147,9 +161,11 @@ jobs:
       PROD_BOTLINK_BOT_CERT: ${{ secrets.PROD_BOTLINK_BOT_CERT }}
       PROD_BOTLINK_BOT_KEY: ${{ secrets.PROD_BOTLINK_BOT_KEY }}
       LOG_LEVEL: ${{ vars.PROD_LOG_LEVEL }}
-      TELEGRAM_MINIAPP_URL: ${{ vars.PROD_TELEGRAM_MINIAPP_URL }}
+      # PUBLIC_BASE_URL drives the derived Mini App URL; SUPPORT_CHAT_ID for parity with deploy.
+      PUBLIC_BASE_URL: ${{ vars.PROD_PUBLIC_BASE_URL }}
       TELEGRAM_GAME_CHANNEL_ID: ${{ vars.PROD_TELEGRAM_GAME_CHANNEL_ID }}
       TELEGRAM_CHAT_ID: ${{ vars.PROD_TELEGRAM_CHAT_ID }}
+      TELEGRAM_SUPPORT_CHAT_ID: ${{ vars.PROD_TELEGRAM_SUPPORT_CHAT_ID }}
       TELEGRAM_BOT_USERNAME: ${{ vars.PROD_TELEGRAM_BOT_USERNAME }}
       TELEGRAM_BOT_LINK: ${{ vars.PROD_VITE_TELEGRAM_LINK }}
     steps:
@@ -163,19 +179,8 @@ jobs:
         run: |
           umask 077
           mkdir -p stage/certs-bot
-          cat > stage/env.bot.sh <<EOF
-          export SCRABBLE_CONFIG_DIR='/opt/scrabble'
-          export BOT_IMAGE='$REGISTRY/scrabble-telegram-bot:$TARGET'
-          export BOTLINK_GATEWAY_ADDR='$MAIN_HOST:9443'
-          export TELEGRAM_BOT_TOKEN='$TELEGRAM_BOT_TOKEN'
-          export TELEGRAM_MINIAPP_URL='$TELEGRAM_MINIAPP_URL'
-          export TELEGRAM_GAME_CHANNEL_ID='$TELEGRAM_GAME_CHANNEL_ID'
-          export TELEGRAM_CHAT_ID='$TELEGRAM_CHAT_ID'
-          export TELEGRAM_PROMO_BOT_TOKEN='$TELEGRAM_PROMO_BOT_TOKEN'
-          export TELEGRAM_BOT_USERNAME='$TELEGRAM_BOT_USERNAME'
-          export TELEGRAM_BOT_LINK='$TELEGRAM_BOT_LINK'
-          export LOG_LEVEL='${LOG_LEVEL:-info}'
-          EOF
+          # Same writer as prod-deploy's deploy-bot (parity; includes TELEGRAM_SUPPORT_CHAT_ID).
+          BOT_IMAGE="$REGISTRY/scrabble-telegram-bot:$TARGET" bash deploy/write-prod-bot-env.sh stage/env.bot.sh
           printf '%s\n' "$PROD_BOTLINK_CA"       > stage/certs-bot/ca.crt
           printf '%s\n' "$PROD_BOTLINK_BOT_CERT" > stage/certs-bot/bot.crt
           printf '%s\n' "$PROD_BOTLINK_BOT_KEY"  > stage/certs-bot/bot.key

CLAUDE.md

@@ -125,9 +125,10 @@ gateway/                     # module scrabble/gateway: Connect-RPC edge, embeds
 ui/                          # Svelte + Vite SPA + landing (Node project, not in go.work)
 pkg/                         # shared: telemetry, version, wire/FlatBuffers, proto, mtls
 platform/telegram/           # Telegram side-service: cmd/validator (HMAC, no VPN) + cmd/bot (Bot API; dials gateway over reverse mTLS bot-link)
+renderer/                    # image-render sidecar (Node + skia-canvas): runs ui/src/lib/gameimage.ts server-side for the finished-game PNG export
 loadtest/                    # module scrabble/loadtest: the load/stress harness
 docs/  .gitea/workflows/  CLAUDE.md  README.md
-backend/Dockerfile gateway/Dockerfile platform/telegram/Dockerfile loadtest/Dockerfile  # multi-stage distroless; gateway/Dockerfile has the `landing` target, platform/telegram/Dockerfile has `validator`+`bot` targets
+backend/Dockerfile gateway/Dockerfile platform/telegram/Dockerfile loadtest/Dockerfile renderer/Dockerfile  # multi-stage distroless (renderer: node:22-slim + skia-canvas + fonts); gateway/Dockerfile has the `landing` target, platform/telegram/Dockerfile has `validator`+`bot` targets
 deploy/                      # docker-compose (+ prod overlay + bot host) + ansible provisioning + caddy + landing + otelcol (OTLP + docker_stats) + prometheus/tempo/grafana + node_exporter + postgres_exporter; prod-deploy.sh
 ```
 
@@ -143,6 +144,7 @@ go run ./backend/cmd/backend    # /healthz, /readyz on :8080
 
 cd ui && pnpm install && pnpm check && pnpm test:unit && pnpm build  # the UI
 pnpm start                      # UI mock mode: lobby -> game, no backend
+cd renderer && pnpm install && pnpm test  # image-render sidecar (bundles ui/src/lib/gameimage.ts, skia smoke)
 
 docker build --build-arg DICT_VERSION=v1.3.0 -f backend/Dockerfile -t scrabble-backend .  # DICT_VERSION required (no default); gateway embeds the SPA
 docker build -f gateway/Dockerfile --target gateway -t scrabble-gateway .

PLAN.md

@@ -0,0 +1,712 @@
+# PLAN — monetization implementation
+
+Technical, step-by-step implementation of the monetization domain. Business mechanics and
+the rationale for every rule live in [`docs/PAYMENTS.md`](docs/PAYMENTS.md) (RU mirror
+[`docs/PAYMENTS_ru.md`](docs/PAYMENTS_ru.md)); the frozen owner agreements they both derive
+from (the `D1`–`D41` decisions log) live in
+[`docs/PAYMENTS_DECISIONS_ru.md`](docs/PAYMENTS_DECISIONS_ru.md) — the authority when a rule
+is disputed. This file is the *how*. Each stage is written to be self-sufficient: returning
+to it gives full context — goal, exact touch-points, tests, done-criteria, and current
+status — without re-deriving decisions.
+
+## How to use this file
+
+- **Stage granularity (E0–E9) is fixed.** Do not split or merge stages. Plan each stage
+  densely enough to execute whole.
+- **Never leak stage ids into the product.** Code, comments, commit messages, PR
+  titles/descriptions must read as finalized feature copy — never "E5", "stage 3", etc.
+  Stage ids exist only in this file.
+- **Deviations are allowed** when new unknowns surface, but the plan is then edited **whole
+  and in agreement** (not piecemeal), keeping it coherent, and `docs/PAYMENTS.md` updated in
+  step.
+- **Status marks:** each stage header carries `Status: TODO | WIP | DONE`. When a stage
+  lands, flip it to DONE and note the PR. The **Progress** table is the at-a-glance index.
+- **Per-change discipline** (repo `CLAUDE.md`): update tests at the layers `docs/TESTING.md`
+  calls out, bake doc updates into the same PR, run local full verification before pushing,
+  feature branch → PR into `development`.
+
+## Progress
+
+| Stage | Title | Release | Status |
+|-------|-------|---------|--------|
+| E0 | Payments data foundation | 1 | DONE |
+| E1 | Trusted platform signal | 1 | DONE |
+| E2 | Currency + benefit core | 1 | DONE |
+| E3 | Wallet UI | 1 | DONE |
+| E4 | Durability (PITR) | 2 | WIP |
+| E5 | Payment intake | 2 | TODO |
+| E6 | Ads | 2 | TODO |
+| E7 | Admin & reports | 2 | TODO |
+| E8 | Guest limits | — | TODO |
+| E9 | Tournament fee | future | TODO |
+
+**Release 1** = full mechanics with no real money, exercised via `admin_grant` (E0→E1→E2→E3).
+**Release 2** = money (E4→E5→E6→E7). E8 is standalone (game-behaviour change, can run in
+parallel). E9 is future.
+
+---
+
+## Architecture baseline (applies to all stages)
+
+Read once; individual stages assume it.
+
+### Schema & isolation
+
+- The payments domain owns its **own Postgres schema `payments`** in the shared instance
+  (`scrabble` DB). All payments tables are `payments.*`. `backend` schema is untouched
+  except for the deprecation of two legacy columns (E2).
+- **DB role.** A dedicated **NOLOGIN** role holds ALL privileges on `payments.*` and
+  **nothing** on `backend` — grant-based confinement, asserted by a `SET ROLE` isolation
+  test. The application still connects on its single (superuser) pool, so these grants are a
+  stepping-stone to a real separate login/process, not the runtime wall. The **runtime wall
+  is code-level**: only the `internal/payments` package imports the payments jet code and
+  issues `payments.*` SQL (an **import-boundary test** enforces it); every other domain
+  reaches payments through the narrow Go interface.
+- **No cross-schema link at all.** There is **no** foreign key from `payments.*` to
+  `backend.accounts`: `account_id` is a plain `uuid`, kept referentially honest in code and
+  joined to the tombstoned account / `retained_identities` dossier by the stable id. This
+  keeps the spend transaction (ledger INSERT + balance UPDATE + benefit UPDATE) fully
+  **within `payments`** and the domain extractable into its own database later. Benefits move
+  **into** `payments` (they no longer live on `accounts` — see E2); game code reads them
+  through the payments **Go interface**, never via SQL.
+- **Money.** Monetary amounts are a single **`bigint` in the currency's minor units** (RUB
+  kopecks; Votes/Stars/chips are whole units, scale 1) carried in Go by the `payments.Money`
+  value type — the sole constructor/formatter/arithmetic, so **no `float64` ever touches an
+  amount** and a whole-unit currency structurally cannot hold a fraction. `chip_rate` is not a
+  table: a chip pack is a product, so its per-method rate **is** `product_price`.
+
+### Domain boundary
+
+- New package `backend/internal/payments/` — `payments.go` (types + `Service`),
+  `store.go` (`type Store struct{ db *sql.DB }`, go-jet against `internal/postgres/jet/
+  payments`), following the `ads` domain shape (`backend/internal/ads/{ads,service,store}.go`).
+- Wired in `backend/cmd/backend/main.go` `run()` (construct after `account`, before
+  `server.New`), handed into `server.Deps` (`server.go`), routes registered in
+  `registerRoutes` gated `if s.payments != nil`, admin section in `registerConsole` gated
+  `if s.payments != nil`.
+- Game/other domains depend on payments only through a **narrow interface** (e.g.
+  `AdFree(ctx, account, platform, present) bool`, `SpendHint(ctx, account, platform, present)
+  error`, `Balances(ctx, account, platform, present) …`), where `present` is the set of
+  identity sources the account currently holds (`vk`→vk, `telegram`→telegram, `email`→direct;
+  `robot` ignored), computed by the caller from `account.Identities` — payments carries no
+  cross-schema identity knowledge, so unlink/re-link availability (D14) falls out live. Keep
+  the surface small; this is the seam that lets payments become a separate process later
+  without touching callers.
+- **Read model.** Hot reads (`AdFree`/`HintsAvailable`/`Balances` and the gate) are served
+  from an in-process, account-keyed, write-through cache inside the payments package
+  (mirroring `account/suspension.go`), invalidated on every payments mutation
+  (spend/grant/fund/refund/merge); the payments DB is touched only on a cache miss, so the
+  steady-state hot path issues no query to the `payments` schema. The D39 materialized
+  `balances`/`benefits` tables stay the in-transaction write target the cache fronts.
+  Single-instance, matching the deployment (a multi-instance backend would need a shared
+  cache).
+
+### Migrations & codegen
+
+- Migrations: same goose dir `backend/internal/postgres/migrations/`, sequential
+  `0000N_*.sql`, `-- +goose Up/Down`, schema-qualified, **expand-contract mandatory**
+  (image rollback must stay DB-safe). First payments migration does `CREATE SCHEMA IF NOT
+  EXISTS payments`, creates the role, grants.
+- **jetgen** (`backend/cmd/jetgen/main.go`) is currently hardwired to `schema=backend`.
+  Extend it to also generate `schema=payments` into `internal/postgres/jet/payments/
+  {model,table}` (committed). Regenerate only after a payments migration; revert unrelated
+  `backend`-schema churn (jetgen may reorder untouched tables — commit only intended diffs).
+- Transactions: reuse the local `withTx(ctx, db, fn)` idiom. Balance/benefit mutations are
+  guarded single-row atomic UPDATEs (mirror `account.SpendHint`); the ledger INSERT +
+  materialized-cache UPDATE go in one `withTx`. Default Read-Committed is sufficient given
+  the guarded updates + unique idempotency keys; do not reach for Serializable without a
+  demonstrated need.
+
+### Transport
+
+- client ↔ gateway: Connect-RPC + FlatBuffers (h2c). gateway ↔ backend: REST/JSON +
+  `X-User-ID` via `gateway/internal/backendclient`. Any user-facing payments call needs the
+  full chain: backend REST handler (`u := s.user` group) → `backendclient` method →
+  Connect-RPC method + transcode (`gateway/internal/transcode/`) → FlatBuffers schema
+  (`pkg/fbs/…`, regen with `make -C pkg fbs` + `pnpm -C ui codegen`).
+- Provider webhooks (Robokassa/VK) do NOT use the Connect path — model on the existing
+  public HMAC-signed route `s.public.GET("/dl/:id/:kind", …)` (`handlers.go`): a public
+  route with signature verification, proxied by the gateway/Caddy `@gateway` matcher
+  (`deploy/caddy/Caddyfile` — a new edge route MUST be added there or it falls to the
+  landing catch-all).
+
+### Testing layers (`docs/TESTING.md`)
+
+- **unit** (Go `_test.go`, TS vitest): gate-by-context, no-ads stacking, priority draw,
+  rate math, idempotency keys, catalog snapshotting. UI logic must be extracted out of
+  `.svelte` into `ui/src/lib/*` to be unit-testable.
+- **integration** (`backend/internal/inttest/`, `//go:build integration`, Postgres-backed):
+  atomic chip↔benefit spend, callback idempotency, order-flow, TG outbox delivery, merge/
+  unlink of segments.
+- **UI** (Playwright mock e2e, Chromium+WebKit): Wallet screen, warnings, guest-hidden, GP
+  stub. Mock e2e bypasses codec — wire bugs need codec unit tests.
+- Local full verification before push: integration (`-tags=integration` + DAWG sibling +
+  Ryuk-off), UI check/test/build, codegen (`make -C pkg proto fbs`, `pnpm -C ui codegen`).
+
+---
+
+## E0 — Payments data foundation
+
+**Status:** DONE · **Release 1** · depends on: none · mechanics: PAYMENTS §14, §7, §11.
+
+**Goal.** Stand up the `payments` schema, its confinement role, the jetgen target, the domain
+package skeleton and all core tables — nothing wired to real money yet. This is the substrate
+every later stage builds on.
+
+**Migration `00010_payments_foundation.sql` (`payments` schema).**
+
+- `CREATE SCHEMA payments`; an idempotent `DO $$` block creates a **NOLOGIN** `payments` role;
+  `GRANT USAGE` + `GRANT ALL ON ALL TABLES` (+ `ALTER DEFAULT PRIVILEGES … GRANT ALL`) confine it
+  to `payments.*` with nothing on `backend`. No `REFERENCES` grant (there is no cross-schema FK).
+- `payments.ledger` — append-only. `ledger_id` (uuid PK, app-generated v7), `account_id` (plain
+  `uuid`, **no FK**), `kind` (`fund|spend|admin_grant|refund`), `source`/`origin` (nullable,
+  `vk|telegram|direct`), `chips_delta` (signed int, 0 for a grant), `product_id` (nullable
+  FK→product), `order_id` (nullable FK→orders), `provider` + `provider_payment_id` (nullable),
+  `snapshot` (jsonb, written from E2), `created_at`. Immutability is a **`BEFORE UPDATE OR DELETE`
+  trigger** (a superuser bypasses a privilege REVOKE). Unique **partial** index on `(provider,
+  provider_payment_id) WHERE provider_payment_id IS NOT NULL` — the idempotency key.
+- `payments.balances` — `(account_id, source)` PK, `chips int CHECK (>=0)`, `updated_at`. Created
+  **lazily** on first fund (up to three rows/account, absent = zero).
+- `payments.benefits` — `(account_id, origin)` PK, `ads_paid_until timestamptz` null,
+  `ads_forever bool`, `hints int CHECK (>=0)`, `updated_at`. Created lazily.
+- `payments.catalog_atom` — `atom_type` PK (`chips|hints|noads_days|tournament`); the four atoms
+  are **seeded** here (the `tournament` atom is provisioned for E9).
+- `payments.product` (`product_id` PK, `title`, `active bool` soft-delete, timestamps);
+  `payments.product_item` (`(product_id, atom_type)` PK → `quantity`); `payments.product_price`
+  (`(product_id, COALESCE(method,''), currency)` unique → `amount bigint` minor units): a chip
+  pack carries a money price per `method` (`vk|telegram|direct`), a value carries one
+  `currency='CHIP', method=NULL` row. `currency ∈ {RUB, VOTE, XTR, CHIP}`; `amount CHECK (>=0)`.
+- `payments.config` — a single typed row (`only_row bool PK CHECK`): `rewarded_payout_chips`,
+  `cooldown_global_seconds` (300), `cooldown_vs_ai_seconds` (1800), `cooldown_hint_seconds` (60),
+  `order_ttl_seconds` (1800). No `chip_rate` table — the pack rate is `product_price`.
+- `payments.orders` — `order_id` (uuid PK), `account_id`, `platform`, `product_id` (FK),
+  `expected_amount bigint` + `currency`, `origin`, `status` (`pending|paid|expired`), `provider`,
+  `provider_payment_id` (nullable), timestamps. Index `(status, created_at)` for the pending sweep.
+- `payments.payment_events` — `event_id` (uuid PK), `account_id`, `order_id` (nullable FK), `type`
+  (`succeeded|failed|refunded`), `payload jsonb`, `created_at`, `dispatched_at` (nullable, partial
+  index for the dispatch queue).
+- Full `-- +goose Down` (DROP SCHEMA CASCADE + DROP OWNED BY + DROP ROLE); expand-contract, proven
+  reversible by an integration test.
+
+**Backend.**
+
+- `backend/internal/payments/{payments,service,store}.go` — the `Money` value type + `Currency`
+  (bigint minor units, exact, no float); `Store{db *sql.DB}` with a `Ping` health read via jet;
+  `Service` over the store. (`withTx` arrives with E2's first transaction.)
+- `cmd/jetgen` generates the `payments` schema into `internal/postgres/jet/payments/` (a second
+  `GenerateDB` call); committed. Constructed in `cmd/backend/main.go` and passed to `server.Deps`
+  (`Payments`) with a boot-time reachability check; its routes are registered from E2.
+
+**Legacy deprecation (expand phase only).** A `--` header note marks `accounts.hint_balance` and
+`accounts.paid_account` deprecated; they are **not** dropped (the DROP is the contract phase after
+E2 flips reads and after Release 2). Reads still use the old columns until E2.
+
+**Tests.**
+
+- integration (`inttest`): schema + role + seeds present; `SET ROLE payments` cannot read
+  `backend.accounts` (grant confinement); ledger rejects UPDATE/DELETE (trigger); idempotency
+  partial index holds (NULL-keyed rows repeat); balance/benefit/amount/enum CHECKs bite; migration
+  applies forward **and backward** on a throwaway PG.
+- unit: `Money` — exact round-trip, per-currency scale, no-float parse rejecting a fraction for a
+  whole-unit currency, arithmetic, formatting. Import-boundary test: only `internal/payments`
+  imports the payments jet code.
+
+**Done-criteria (met).** Migrations apply forward+backward on a throwaway PG 17; `go build
+./backend/...` + `go vet` + `gofmt -l .` clean; committed `jet/payments/`; all tests green; no
+behaviour change for users.
+
+**Notes.** jetgen regenerates the whole `backend` schema; its committed jet had drifted from the
+migrations (`robot_blocks`, `robot_friend_requests`, the `feedback_messages` `app_version` /
+`browser_tz` columns, and `UseSchema` gaps), so this change also **regenerates and commits
+`jet/backend`** to bring it back in sync (additive only — all suites stay green). The `payments`
+role creation is idempotent (`DO $$` / `IF NOT EXISTS`) for fresh volumes.
+
+---
+
+## E1 — Trusted platform signal
+
+**Status:** DONE · **Release 1** · depends on: none (parallel to E0) · mechanics: PAYMENTS §8.
+
+**Goal.** Make the server know the execution platform from a trusted, unforgeable source,
+carried on the session. This is the foundation the gate (E2) stands on; without it the gate is
+meaningless. Signal plumbing only — no user-visible change.
+
+**Model.** `platform = {kind: vk|telegram|direct, subtype: ios|android|web}` is a property of
+the **session**, captured at creation. `kind` is always trusted — the gateway derives it from
+the validated establish path (VK launch / TG initData / a web-native session), never a client
+field. `subtype` is **cryptographically trusted only for VK** (it rides inside the signed
+`vk_platform` launch param); for telegram and direct it is client-reported best-effort, and the
+gate never relies on it (only the VK-iOS-frozen case is compliance-critical, and VK subtype is
+trusted). VK/TG re-mint a session on **every cold start**, so their platform is re-captured each
+launch; web/direct/email reuse the stored token, so their platform is captured once at creation
+(`direct` needs no signature).
+
+**Validation stays at the gateway.** Both wrapper verifiers already live there and the backend
+cannot import either (separate modules under `internal/`, and the VK app secret is gateway-only):
+VK launch params via the in-process `gateway/internal/vkauth.Verify` (HMAC-SHA256 over the signed
+`vk_*` params under `GATEWAY_VK_APP_SECRET`, extended here to expose the signed `vk_platform` →
+a trusted `Subtype()`), TG `initData` via the validator RPC. The gateway hands the derived
+platform to the backend at establish; the backend persists it and returns it on resolve.
+
+**Backend.**
+
+- `backend.sessions` gains nullable `platform_kind` + `platform_subtype` columns (migration
+  `00011`, CHECK-constrained, jet regenerated). A `session.Platform` value type + `session.Create`
+  captures it; `Session` carries it through the store and the warm cache.
+- `handleResolveSession` → `resolveResponse` (`dto.go`) returns the platform; the establish
+  handlers set `kind` from their own endpoint (`/sessions/telegram|vk|guest|email/*`) and
+  `subtype` from the request (VK: gateway-extracted from the signed params; TG/direct: the client
+  best-effort field, defaulting web). The account-merge session mint (`link.merge`) inherits the
+  caller's platform from the request context.
+- Middleware (`middleware.go`) parses the gateway-injected `X-Platform` into the request context
+  on the `s.user` group; `platform(c)` exposes it. Absent ⇒ untrusted (fail-closed).
+
+**Gateway.**
+
+- `backendclient.WithPlatform(ctx, "<kind>/<subtype>")` + `do`/`getRaw` inject `X-Platform` on
+  every authenticated backend call; `connectsrv.Execute` enriches the request context from the
+  resolved session's platform (carried through the gateway session cache + `ResolveSession`).
+  Never from a client request body.
+
+**Client (`ui/`).** `platformSubtype()` (`ui/src/lib/platform.ts`) supplies a best-effort device
+subtype on the `auth.telegram` / `auth.guest` / `auth.email.login` requests (new FBS `subtype`
+field): Telegram's `WebApp.platform` inside a Mini App, else the Capacitor/web channel. VK sends
+nothing (the gateway derives the trusted subtype from the signed launch params).
+
+**Tests.**
+
+- unit (Go): `vkauth` exposes the signed `vk_platform` and maps iPhone/iPad → ios (the frozen
+  case); the `X-Platform` middleware round-trips + reports untrusted when absent; the backend
+  client injects `X-Platform` from the context and omits it when untrusted.
+- integration: a session carries its platform through create + a cold-cache (DB) resolve for each
+  kind; an unattributed session is untrusted; the CHECK constraints bite; migration `00011`
+  applies forward **and backward** on a throwaway PG.
+- UI: subtype normalization (vitest) + the new `subtype` field on the wire (codec unit test).
+
+**Done-criteria (met).** A VK/TG session resolves to a trusted `{kind, subtype}`; a forged body
+cannot change `kind` (nor the VK subtype); `direct` sessions resolve to `direct`; the untrusted
+path is reachable and observable via `platform(c)`. No user-visible change; all layers green.
+
+**Notes/risks.** High blast-radius (auth/session table + broad gateway header threading): additive
+migration, no mixed-in refactors, `X-Platform` inert until E2 consumes it. **Sessions minted before
+E1 carry no platform → untrusted (view-only) until re-login**; VK/TG self-heal on the next
+cold-start re-mint, direct/email do not (accepted: Release 1 has no money, sessions cycle by
+Release 2). TG/direct subtype is not cryptographically trusted — E2 must keep the gate on `kind`
++ the trusted VK subtype only.
+
+---
+
+## E2 — Currency + benefit core
+
+**Status:** DONE · **Release 1** · depends on: E0, E1 · mechanics: PAYMENTS §2–§6, §11.
+
+**Goal.** The full internal money mechanic, exercisable end-to-end **without real money**
+via `admin_grant`: chip balances, spend→benefit atomically, the compliance gate by context,
+benefit application (no-ads stacking, hints per-origin), the legacy migration, and the
+`SpendHint` rewrite. This is the heart.
+
+**Payments service (Go).** Every read/gate method also takes `present` (the account's live
+identity sources, see *Domain boundary*) and is served from the read cache.
+
+- `Balances(ctx, account, platform, present)` → per-segment `{source, chips, spendable}` for
+  the context (VK→vk spendable, direct/tg hidden; TG→tg; direct→direct+vk+tg by priority;
+  VK-iOS→vk shown as a **frozen** number, none spendable; untrusted→view-only, none spendable).
+- `Spend(ctx, account, platform, present, productID)` → gate-checked purchase of a **value**
+  (CHIP price, `method=NULL`; never a chip pack) with chips: resolve spendable segments by
+  context, draw by priority direct→vk→tg, write a `spend` ledger row (+ a catalog **snapshot**
+  of atoms+price) + decrement balance + apply benefit (extend `ads_paid_until[origin]` from
+  `max(now,end)` / set `ads_forever` / add hints) **in one tx**, stamping `origin` = platform
+  context. Refuse if untrusted (fail-closed) or funds insufficient.
+- `Grant(ctx, account, origin, atoms)` → a **0-price sale of a value**: an `admin_grant`
+  ledger row (`chips_delta=0`, + snapshot), same benefit application; concrete values only,
+  never chips (no chips move — it neither requires nor touches a balance). Origin chosen by
+  the admin. In E2 this is the Go service method only, exercised by tests; the admin grant UI
+  + catalog editor are E7.
+- `AdFree(ctx, account, platform, present)` / `HintsAvailable(…)` / `SpendHint(…)` → apply
+  the one-directional origin rule: in context P, usable origins = {P} plus, when P is
+  web/native, {vk,tg} (relaxation outward); in VK only vk; in TG only tg. Hint consumption
+  draws by the same priority direct→vk→tg.
+- `Merge` / `Unlink` hooks: extend `accountmerge` to merge segments **and** benefits by origin
+  (same-origin add — chips sum, terms extend per origin; different origins coexist) in the
+  caller's tx (`MergeTx`), and make **both** segment *and* benefit availability follow
+  identity presence — unlink sleeps the balance *and* the benefit, re-link wakes them (D14),
+  resolved live from `present`. Warn-before-unlink surfaces the balance via the interface; the
+  warning UI itself is not E2.
+
+**Backend wiring & migration.**
+
+- Deprecate-and-flip `accounts.hint_balance` / `accounts.paid_account`: E0 added the tables;
+  here, move reads/writes to `payments.benefits`. `SpendHint` (`game/service.go` ~:1147) and
+  `ads.Eligible` (`ads/ads.go` :107) call the payments interface instead of the account
+  columns. Legacy values were never set in prod → zero them; the DROP is the contract phase
+  (guarded, after Release 2 — keep columns until then for rollback safety).
+- `vs_ai` hints stay free/unlimited (unchanged 30-min gate); only online-game hint spend
+  routes through the segmented, context-aware path.
+
+**API (user-facing, Connect chain).** Read-only wallet view + spend:
+`GET /api/v1/user/wallet` (balances+benefits for the context), `POST /api/v1/user/wallet/
+buy` (spend chips on a product). Add the backend handlers (`u := s.user`), `backendclient`
+methods, Connect methods + transcode + FBS. Admin grant is internal/admin (E7 UI).
+
+**Tests.**
+
+- unit (Go): gate-by-context matrix (every row of PAYMENTS §4, incl. VK-iOS frozen +
+  untrusted); priority draw; no-ads stacking (`+=` from max(now,end)) + forever override;
+  per-origin hint applicability + direct→vk→tg draw; merge/unlink segment+benefit math;
+  catalog snapshotting; read-cache invalidation on each mutation.
+- integration: atomic spend (ledger+balance+benefit in one tx; failure rolls all back);
+  admin_grant credits values not chips; legacy migration zeroes and flips reads; merge/
+  unlink over Postgres.
+- UI: none new (E3 builds the screen); wallet DTO covered by codec unit tests.
+
+**Done-criteria.** `admin_grant` applies no-ads/hints directly (a 0-price sale of a value —
+no chips involved); the player chip-spend path (`Spend`) is proven by unit/integration tests
+(balance seeded in-test, since a legitimate chip source arrives only with Release 2); the gate
+blocks cross-context spend and cross-origin application; the ads gate reads the new benefit;
+`SpendHint` uses segments; the hot read paths hit the read cache, not the `payments` schema;
+all layers green; **compliance regression** (a `direct` benefit never activates inside VK/TG)
+is a named test.
+
+**Notes/risks.** This is the high-blast-radius core (money semantics + a live path
+`SpendHint`/`ads.Eligible`). Minimize surface, keep the interface narrow, no mixed-in
+refactors. The legacy flip is expand-contract: reads move first, DROP much later.
+
+---
+
+## E3 — Wallet UI
+
+**Status:** DONE · **Release 1** · depends on: E2 · mechanics: PAYMENTS §1, §7, §6, §13, §4.
+
+**Goal.** The user-facing "Кошелёк" (Wallet) section: balances + active benefits + the
+catalog storefront, honouring guest-hidden, GP-stub, and the web-spend warning.
+
+**Backend + wire (catalog read — new).** E2 shipped `wallet.get` / `wallet.buy` (segments +
+benefits + a chip spend) but no way to *list* the catalog; the storefront needs one, so E3 adds a
+read path following the E2 shape:
+
+- `payments.Service.Catalog(ctx, cxt)` + `store.loadCatalog` (`internal/payments/{catalog,
+  store_catalog}.go`) read every **active** product with atoms and prices and project them to the
+  context (`projectCatalog`, pure + unit-tested): a **value** (no `chips` atom) carries its CHIP
+  price and shows everywhere; a **chip pack** (`chips` atom) carries the money price for the
+  context method (`cxt.Kind`: vk→VOTE, telegram→XTR, direct→RUB) and shows only where that method
+  is priced. Read **uncached** (the catalog is small and rarely edited — unlike the per-account
+  balances/benefits the read cache fronts).
+- REST `GET /api/v1/user/wallet/catalog` (`handleWalletCatalog`, gated by `walletGate`) →
+  `catalogDTO`; gateway op `wallet.catalog` (`transcode.go` + `encodeCatalog`), `backendclient.
+  Catalog`; FBS `Catalog`/`CatalogProduct`/`CatalogAtom` (`pkg/fbs/scrabble.fbs`), client
+  `decodeCatalog`.
+
+**UI (`ui/`).**
+
+- New `'wallet'` tab in `ui/src/screens/SettingsHub.svelte` — `SettingsTab` union, tab button
+  **between Friends and About** (guest-hidden like Friends, offline-disabled like Profile/Friends),
+  body branch, `'wallet'` route in `ui/src/lib/routeparse.ts` + `ui/src/App.svelte`.
+- `Wallet.svelte` screen: context-available chip balances + active benefits (no-ads until date /
+  forever, hints count). **No history feed** (PAYMENTS §11 — noise). Storefront: values priced in
+  chips (buyable with `wallet.buy`), chip packs priced per method.
+- **Guest:** section hidden entirely (durable-only).
+- **GP build:** the chip-pack purchases are hidden behind a RuStore stub; spending earned chips on
+  values still works (PAYMENTS §13). Detected by a build-time flag `VITE_GP_BUILD`
+  (`ui/src/lib/distribution.ts`), forcible under the mock e2e with `?gp`.
+- **Web-spend warning:** before a value spend that would draw vk/tg chips in a direct context, an
+  own `Modal` (not `showPopup`) warns the benefit will be web/native-only. The context is inferred
+  client-side (`executionContext` — VK/Telegram/direct); the server enforces the real gate on
+  `wallet.buy` (fail-closed), so no wallet-DTO change was needed.
+- Logic extracted to `ui/src/lib/{wallet,distribution}.ts` (unit-testable); `.svelte` stays thin.
+
+**Pack purchase is display-only in E3.** Buying a chip pack needs the money order flow, which is
+**E5**; here a pack card shows its price with a disabled **"Soon"** action. E5 replaces that with the
+launch/order CTA. Value spends are wired now (E2 `wallet.buy`), though a Release-1 durable account
+has 0 chips until funding exists (E5/E6), so a real value spend returns insufficient-funds until then.
+
+**Tests.**
+
+- unit (Go): `projectCatalog` context matrix (value everywhere; pack per context method; misconfig
+  omitted). unit (vitest): money/price formatting, spendable-segment selection, warning trigger,
+  the GP flag; `decodeCatalog` codec round-trip (mock e2e bypasses the codec).
+- integration (`inttest`): `/wallet/catalog` returns active products with the context-correct price
+  over Postgres; soft-deleted excluded.
+- UI (Playwright mock, Chromium+WebKit): Wallet renders between Friends/About; guest hides it
+  (`?guest` seam); GP stub (`?gp`); warning modal on a vk-drawing web spend, no warning on a
+  direct-covered spend. Mock overlay stays instant under `MODE==='mock'` (or it intercepts taps).
+
+**Done-criteria (met).** Balances/benefits/storefront render per context; guest/GP/warning paths
+verified by unit + integration + mock e2e on both engines. **A *populated* contour review depends
+on later stages** (no products until the E7 catalog editor, no chip funding until E5/E6, no grant
+UI until E7): on the contour E3 shows the correct **empty** wallet/storefront states; the populated
+UI is proven by the mock e2e. (This replaces the earlier "demonstrable end-to-end via `admin_grant`"
+line — the grant UI is E7.)
+
+**Notes/risks.** No global `.btn`/`.ghost` in `ui/` — styled per-component with scoped CSS + tokens
+(mirror NewGame `.invite`). Product titles are single-language catalog data (E0 `product.title`),
+shown verbatim; currency/chip words are i18n, counts follow the app's label+number convention (no
+noun agreement). Svelte whitespace/`$state` naming gotchas apply.
+
+---
+
+## E4 — Durability (PITR)
+
+**Status:** WIP — repo artifacts landed; **prod arming pending** (owner-coordinated, before
+E5). · **Release 2** · depends on: E0 (schema exists) · mechanics: PAYMENTS §14 (D4).
+
+**Goal.** Continuous WAL archiving with point-in-time recovery, armed **before the first
+real money** is accepted (E5 prod). Protects both money and game data.
+
+**Locked decisions (this stage).**
+
+- **Tool: pgBackRest.** **Destination: Selectel S3** object storage (encrypted AES-256-CBC,
+  path-style addressing), **prod main host only** — the test contour never archives. (D4 left
+  the tool + destination open; resolved here. Warm replica stays deferred, per D4.)
+- **Retention 30 days**, **daily full base backup** (a systemd timer) + continuous WAL
+  (`archive_command`, a 5-minute forced switch bounds the recovery point). Assessment
+  (owner-reviewed prod gate): measured prod WAL **~0.77 MB/day**, DB **~9.6 MB** → archive
+  **< 1 ₽/month** on Selectel S3, **negligible** perf impact. Recorded in `deploy/README.md`.
+- **Archiving ships gated OFF** (`PGBACKREST_ARCHIVE_MODE` on the DB, `pitr_enabled` for the
+  timer — both default off), so the merged/redeployed artifact is inert until armed and an
+  un-armed prod deploy **cannot** pile WAL onto the disk.
+
+**Work (landed in the artifacts PR into `development`).**
+
+- pgBackRest in the DB image (`deploy/postgres/Dockerfile`); postgres becomes a built + pushed
+  image (prod overlay `image:` + `prod-deploy.yaml` build/push list).
+- Repository config + `archive_mode` via `PGBACKREST_*` env on the prod-overlay postgres
+  service; secrets/vars rendered by `deploy/write-prod-env.sh` from the `PROD_PGBACKREST_*`
+  Gitea set; **parity added to `prod-rollback.yaml`** (a rollback must not disarm archiving).
+- Daily base-backup systemd timer (Ansible `main` role, gated by `pitr_enabled`).
+- Two Grafana alerts on the exporter's `pg_stat_archiver` metrics (failing / stalled),
+  absent/NaN-safe on the contour.
+- Belt-and-braces `pg_dump` fixed to dump the **whole DB** (`deploy/prod-deploy.sh` was
+  `-n backend`, silently excluding `payments`); manual-restore runbook updated.
+- Full PITR runbook + arming sequence + recorded assessment in `deploy/README.md`.
+
+**Prod arming (SEPARATE — owner-coordinated, before E5; NOT the artifacts PR).** Owner creates
+the Selectel S3 bucket + the `PROD_PGBACKREST_*` secrets/variables (incl. `ARCHIVE_MODE=on`);
+then promote `development → master` → `prod-deploy` (archive_mode on behind the maintenance
+window), `pgbackrest stanza-create` + first base backup + `check`, re-run Ansible with
+`-e pitr_enabled=true`, and run the restore drill on an isolated one-shot target. Exact steps:
+`deploy/README.md` (point-in-time recovery — arming).
+
+**Tests.** Restore drill on an isolated one-shot instance (base + WAL → target timestamp),
+recorded in `deploy/README.md`. No app-level tests. Local verification: `docker compose config`
+valid + the custom PG image builds (archiving inert on the contour).
+
+**Done-criteria.** Artifacts merged with archiving inert. **Fully done** at arming: WAL
+archiving live on prod PG; a timed restore verified; cost + perf assessment reviewed; runbook
+current in `deploy/README.md`.
+
+**Notes/risks.** The repository **cipher passphrase is unrecoverable if lost** — stored apart
+from the S3 keys. Enabling `archive_mode` restarts postgres (rides the prod-deploy maintenance
+window). Migrations stay expand-contract so image rollback remains DB-safe alongside PITR.
+
+---
+
+## E5 — Payment intake
+
+**Status:** TODO · **Release 2** · depends on: E0, E1, E2, E4 · mechanics: PAYMENTS §9, §12.
+
+**Goal.** Accept real money on all three rails into the payments domain: order-flow,
+verified provider callbacks, idempotency, the TG bot SQLite outbox, the event dispatcher,
+receipts, and refunds.
+
+**Order-flow & intake (single writer).**
+
+- `POST /api/v1/user/wallet/order` → create `order(pending)` (account/platform/product/
+  expected amount/origin), return the provider-specific launch payload with `order_id`
+  threaded in (Robokassa `InvId` / TG `invoice_payload` / VK `item`). The storefront's chip-pack
+  card wires its purchase CTA to this here, **replacing the disabled "Soon" placeholder E3 left**
+  (`ui/src/screens/Wallet.svelte`).
+- Robokassa + VK **public webhooks**: new edge routes (add to `deploy/caddy/Caddyfile`
+  `@gateway` matcher — or they fall to the landing catch-all), signature/HMAC verified,
+  proxied into a payments intake handler. Match by `order_id`, verify amount, credit
+  (ledger `fund` + balance UPDATE in one tx), mark order `paid`, emit `payment_event`.
+  Idempotent by `(provider, provider_payment_id)`.
+- **Pending sweep:** background reaper expires pending orders after the configured timeout
+  (~30 min). Expiry is cosmetic — a later valid callback still credits (revive/honour).
+
+**TG bot outbox (`platform/telegram/`).**
+
+- The bot receives `successful_payment` (and `pre_checkout_query`) via Bot API. Add a
+  **SQLite** store on the bot's disk: on receipt, persist → ack the Telegram update → forward
+  to a backend payments-intake endpoint (internal, authenticated over the existing reverse
+  mTLS bot-link) → on backend ack, mark `forwarded`. Retries with backoff; re-drive
+  undelivered on restart. Backend intake dedups by `telegram_payment_charge_id`.
+- Provide the invoice creation path (Stars) from the Mini App via the bot as needed.
+
+**Events & notifications.**
+
+- `payment_events` dispatcher: `succeeded`/`failed`/`refunded` → live gRPC stream if the
+  user is connected, else `botlink` push / email relay (existing). "failed" = an active
+  provider decline (not an abandoned pending) surfaced to the user; "succeeded" hook
+  (email/bot message).
+
+**Receipts (§12).** Robokassa self-employed НПД receipt on payment (provider config); VK
+handles Votes tax itself; TG Stars — no receipt.
+
+**Refunds (§9).** ToS non-refundable; admin manual refund (ties to `accountdelete`); external
+`refunded` events honoured — best-effort benefit revoke (never negative; record loss + abuse
+flag if spent), ledger `refund` row. Ledger export-ready (reconciliation not built).
+
+**Tests.**
+
+- unit: signature/HMAC verifiers per rail; order-id matching; idempotency-key dedup.
+- integration: full order→callback→credit per rail; duplicate callback credits once; expired
+  order still honoured on late callback; TG outbox store→forward→ack→cleanup + restart
+  re-drive; refund revoke best-effort/never-negative.
+- UI: purchase flow reaches the provider launch (mock); success/failure surfaced.
+
+**Done-criteria.** A real (sandbox) payment on each rail credits chips exactly once; a
+replayed callback does not double-credit; the TG outbox survives a bot restart mid-flight;
+failed/succeeded events reach the user; refund path exercised. **PITR (E4) armed and the
+cost/perf assessment reviewed before this goes to prod.**
+
+**Notes/risks.** Manual `docker run -p` boot tests fail from the shell — verify the runnable
+artifact via the testcontainers integration suite. Distroless services run UID 65532;
+bind-mounted secrets must be 0644. Edge routes silently fall through if not added to the
+Caddyfile — add a CI probe. The prod rolling deploy skips caddy on config-only changes —
+force-recreate when the Caddyfile changes.
+
+---
+
+## E6 — Ads
+
+**Status:** TODO · **Release 2** · depends on: E2 (chips), E5 (rewarded credits via intake) ·
+mechanics: PAYMENTS §10.
+
+**Goal.** VK video ads: the post-move interstitial (frequency-gated) and the rewarded video
+(credits chips via server verify), plus extending the existing banner suppression to
+per-origin.
+
+**Work.**
+
+- **Provider abstraction:** a small ads-network interface (VK impl now) so a future network
+  for other platforms slots in without rework. VK integration via `ui/src/lib/vk.ts`.
+- **Rewarded:** voluntary view → the network's **server verify callback** → payments intake
+  credits chips to the `vk` segment (client not believed, like a payment). On-launch
+  anti-fraud = provider verify only (no own daily cap; abstraction allows later).
+- **Interstitial** (post-move fullscreen), configurable server values (from `payments`
+  config): global per-user cooldown across all games (default 5 min); `vs_ai` 30 min; a hint
+  application triggers a post-move interstitial independently with its own 1-min cooldown;
+  offline banner-only; respect VK's own frequency caps. Cooldown state tracked server-side
+  (per user) or client-mirrored from a server value — pick and document at implementation.
+- **Banner suppression:** extend `ads.Eligible` (`backend/internal/ads/ads.go` :107) to gate
+  on the **origin benefit applicable in the current context** (E2 interface) instead of the
+  single legacy flag. No-ads suppresses banner + interstitial; rewarded never suppressed.
+
+**Tests.**
+
+- unit: cooldown logic (global 5m / vs_ai 30m / hint-trigger 1m independence); rewarded
+  credit path; banner eligibility per context.
+- integration: rewarded verify → credit exactly once (idempotent like a payment).
+- UI: interstitial shows/respects cooldown (mock); rewarded button; no-ads hides banner +
+  interstitial; rewarded still available under no-ads.
+
+**Done-criteria.** VK rewarded credits chips once per verified view; interstitial respects
+all cooldowns incl. the hint trigger; no-ads suppresses banner+interstitial but not
+rewarded; offline shows banner only.
+
+**Notes/risks.** Crypto-payout networks stay rejected. Rewarded-without-payout is pointless —
+only enable where the network pays (VK). Keep the interstitial frequency as server config so
+it tunes without a store release.
+
+---
+
+## E7 — Admin & reports
+
+**Status:** TODO · **Release 2** · depends on: E2 (ledger/grant), E5 (payments/refunds) ·
+mechanics: PAYMENTS §11.
+
+**Goal.** The admin console financial surface: per-user report, admin grant UI, manual
+refund UI, ledger export.
+
+**Work (`/_gm`, `backend/internal/server/handlers_admin_console.go` + `adminconsole/`).**
+
+- **Per-user financial panel** on the existing user card (`consoleUserDetail` :343,
+  `UserDetailView`): segment balances, payments, spends, grants, refunds, full history —
+  read from the append-only ledger + materialized cache.
+- **Admin grant** action (mirror the existing `POST /_gm/users/:id/grant-hints`): grant
+  concrete values (no-ads days / hints), **origin picker**, **never chips**; writes an
+  `admin_grant` ledger row (E2 `Grant`).
+- **Manual refund** action: admin-initiated refund of a specific order (ties to the refund
+  path); records a `refund` ledger row; best-effort benefit revoke.
+- **Ledger export**: CSV/JSON export of the ledger for tax reporting + future Robokassa
+  reconciliation (export-ready schema; reconciliation itself not built).
+- Auth unchanged: gateway Basic-Auth in front of `/_gm` + backend same-origin CSRF on POSTs.
+
+**Tests.**
+
+- unit: report view assembly; grant refuses chips; export shape.
+- integration: grant/refund write correct ledger rows; report reflects balances+history.
+
+**Done-criteria.** An operator can see a user's full financial picture, grant concrete
+values (origin-picked, never chips), issue a manual refund, and export the ledger.
+
+**Notes/risks.** `/_gm` per-user detail already surfaces `PaidAccount`/`HintBalance` — replace
+those with the segmented view as the legacy columns retire.
+
+---
+
+## E8 — Guest limits
+
+**Status:** TODO · **standalone** (game-behaviour change; can run in parallel) · depends on:
+none · mechanics: PAYMENTS §6.
+
+**Goal.** A registration funnel: cap what a guest can do, enforced **server-side** (today the
+gating is UI-only).
+
+**Finding (verified).** The friend/invitation paths do **not** check `is_guest` on the
+server — only the UI hides them: `social/friends.go:50` `SendFriendRequest`,
+`robotfriends.go:41` `RequestInGame`, `friendcodes.go:67` `RedeemFriendCode`,
+`lobby/invitations.go:208` `CreateInvitation`. A guest with a valid `X-User-ID` can call them
+in the UI's stead.
+
+**Work.**
+
+- **Server guest gate** on friend-request / redeem-code / invitation-create: refuse when the
+  caller `is_guest` (add an `ErrGuestForbidden`-style guard, as `feedback` already has).
+- **Active-game limits** for guests: at most **1 random-opponent game + 1 vs_ai** concurrently
+  (enforce on game/invitation creation in `lobby`/`game`; today no such limit exists).
+- Keep the existing UI gating; this adds the server as the source of truth.
+
+**Tests.**
+
+- integration: guest is refused friend/redeem/invitation server-side; guest blocked from a
+  2nd random / 2nd vs_ai; durable account unaffected.
+- UI: guest sees the funnel (existing hides + any new messaging).
+
+**Done-criteria.** Guests are server-limited to 1 random + 1 vs_ai and cannot friend/invite;
+durable accounts unchanged; regression that this does not break existing durable flows.
+
+**Notes/risks.** This changes existing game behaviour — its own tests, its own PR, no
+mixed-in payments changes. Decide whether a guest may finish an already-started game (limit
+on creation, not mid-game) at implementation and record it here.
+
+---
+
+## E9 — Tournament fee (future)
+
+**Status:** TODO · **future** · depends on: E0 (atom provisioned), tournament feature ·
+mechanics: PAYMENTS §5, §7.
+
+**Goal.** Charge a chip entry fee for tournaments. The `tournament` atom + a catalog product
+are provisioned in E0/E7; the spend mechanic reuses E2 (`Spend`). The actual tournament
+feature and its coupling to entry are out of scope until the tournament feature exists.
+
+**Done-criteria.** Deferred — revisit when tournaments are built.
+
+---
+
+## Verification & CI (all stages)
+
+- Per-stage tests at the layers above; **compliance-gate regression is mandatory** (a
+  `direct` benefit must never activate inside VK/TG) and runs from E2 onward.
+- Local full verification before every push: `go build/vet ./backend/... && gofmt -l .`,
+  integration (`-tags=integration` + DAWG sibling + Ryuk-off), `pnpm -C ui check/test:unit/
+  build`, Playwright mock e2e, codegen (`make -C pkg proto fbs`, `pnpm -C ui codegen`).
+- Contour: each PR into `development` auto-deploys the test contour; owner does visual sign-
+  off there (not local). Keep a multi-PR batch a linear stack (one shared contour,
+  last-deploy-wins).
+- Prod (Release 2): expand-contract migrations only (image rollback DB-safe); PITR armed +
+  the E4 cost/perf assessment reviewed **before** the first money; new edge routes added to
+  the Caddyfile with a CI probe; caddy force-recreated on config-only changes.
+- Release framing: **shipped docs/code/commits/PRs carry no stage ids** — finalize copy for
+  the release, not the plan.

assets/icons/README.md

@@ -0,0 +1,41 @@
+# Erudit — site icons + Open Graph card
+
+The favicon set and the `og:image` link-preview card for the public landing
+(`ui/landing.html`) and the SPA shell (`ui/index.html`). Same design language as the
+[VK loading-screen logo](../vk/README.md): the wooden Erudit «Э» tile (score `8`),
+with the wordmark on the app's dark board green (`ui/src/app.css` tokens).
+
+| Output (committed to `ui/public/`) | Purpose |
+|------|---------|
+| `favicon.svg` | Vector favicon, transparent; tile + «Э» only (the score is illegible below ~32 px). |
+| `favicon.ico` | 32×32 PNG-in-ICO fallback (also answers the browsers' blind `/favicon.ico` probe). |
+| `apple-touch-icon.png` | 180×180 opaque full-bleed tile; iOS masks its own corners. |
+| `og-image.png` | 1200×630 card: tile + «Эрудит / Скрэббл — игра в слова». Referenced absolutely as `https://erudit-game.ru/og-image.png`. |
+
+## How it works
+
+`build/extract.js` extracts the needed glyph outlines (tile glyphs + every wordmark
+character) from LiberationSans (Arial-metric, the game's font stack) with their
+advance widths into `build/glyphs.json` (committed). `build/generate.js` composes
+plain SVG from those outlines — no font is needed at generation time — writes
+`favicon.svg` and rasterises the PNG/ICO outputs by screenshotting the SVGs with the
+`ui` package's Playwright chromium (`@playwright/test`); the `.ico` container is
+assembled in-script (a single PNG entry). Raster bytes therefore depend on the
+installed chromium version; the SVG sources are deterministic.
+
+## Regenerate
+
+Requirements: Node ≥ 18, `ui` installed (`pnpm install`, provides Playwright).
+`extract.js` additionally needs `opentype.js` (`npm i opentype.js`); **`generate.js`
+needs no extra packages**.
+
+```sh
+cd assets/icons
+
+# 1. (optional) re-extract the glyphs — only if the font or the wordmark changes:
+#    default font: /usr/share/fonts/truetype/liberation/LiberationSans-Regular.ttf
+node build/extract.js [/path/to/font.ttf]      # -> build/glyphs.json
+
+# 2. regenerate everything in ui/public/:
+node build/generate.js
+```

assets/icons/build/extract.js

@@ -0,0 +1,78 @@
+'use strict';
+// Extract the glyph outlines the site icons and the og-image wordmark need from a
+// grotesque font (LiberationSans = Arial-metric, matching the game's system-ui/Arial
+// stack) and emit cubic-bezier contours per character, baseline at y=0, y-down,
+// plus the advance width so generate.js can lay out words without the font.
+// Same outline conversion as ../../vk/build/extract.js, generalised to a char set.
+const opentype = require('opentype.js');
+const fs = require('fs');
+
+const FONT = process.argv[2] || '/usr/share/fonts/truetype/liberation/LiberationSans-Regular.ttf';
+const b = fs.readFileSync(FONT);
+const font = opentype.parse(b.buffer.slice(b.byteOffset, b.byteOffset + b.byteLength));
+const FS = 1000; // em scale
+
+// The tile glyphs («Э», «8») + every character of the og-image wordmark lines
+// («Эрудит», «Скрэббл — игра в слова»). The space carries only an advance.
+const CHARS = [...new Set('Э8рудитСкэббл—игра в слова')];
+
+function glyphData(ch) {
+  const g = font.charToGlyph(ch);
+  const p = g.getPath(0, 0, FS); // baseline at y=0, y-down
+  const contours = [];
+  let cur = null, prev = null;
+  for (const c of p.commands) {
+    if (c.type === 'M') {
+      if (cur) contours.push(cur);
+      cur = [{ v: [c.x, c.y], i: [c.x, c.y], o: [c.x, c.y] }];
+      prev = { x: c.x, y: c.y };
+    } else if (c.type === 'L') {
+      cur.push({ v: [c.x, c.y], i: [c.x, c.y], o: [c.x, c.y] });
+      prev = { x: c.x, y: c.y };
+    } else if (c.type === 'C') {
+      cur[cur.length - 1].o = [c.x1, c.y1];
+      cur.push({ v: [c.x, c.y], i: [c.x2, c.y2], o: [c.x, c.y] });
+      prev = { x: c.x, y: c.y };
+    } else if (c.type === 'Q') {
+      const c1 = [prev.x + 2 / 3 * (c.x1 - prev.x), prev.y + 2 / 3 * (c.y1 - prev.y)];
+      const c2 = [c.x + 2 / 3 * (c.x1 - c.x), c.y + 2 / 3 * (c.y1 - c.y)];
+      cur[cur.length - 1].o = c1;
+      cur.push({ v: [c.x, c.y], i: c2, o: [c.x, c.y] });
+      prev = { x: c.x, y: c.y };
+    } else if (c.type === 'Z') {
+      if (cur && cur.length > 1) {
+        const last = cur[cur.length - 1], first = cur[0];
+        if (Math.hypot(last.v[0] - first.v[0], last.v[1] - first.v[1]) < 1e-3) {
+          first.i = last.i; // fold the duplicate closing point into the first
+          cur.pop();
+        }
+      }
+      if (cur) { contours.push(cur); cur = null; }
+    }
+  }
+  if (cur) contours.push(cur);
+
+  let minx = Infinity, miny = Infinity, maxx = -Infinity, maxy = -Infinity;
+  const out = contours.map(ct => {
+    const v = [], i = [], o = [];
+    ct.forEach(pt => {
+      v.push(pt.v);
+      i.push([pt.i[0] - pt.v[0], pt.i[1] - pt.v[1]]);
+      o.push([pt.o[0] - pt.v[0], pt.o[1] - pt.v[1]]);
+      minx = Math.min(minx, pt.v[0]); maxx = Math.max(maxx, pt.v[0]);
+      miny = Math.min(miny, pt.v[1]); maxy = Math.max(maxy, pt.v[1]);
+    });
+    return { i, o, v, c: true };
+  });
+  const bbox = out.length
+    ? { x: minx, y: miny, w: maxx - minx, h: maxy - miny }
+    : { x: 0, y: 0, w: 0, h: 0 }; // the space has no outline
+  return { adv: g.advanceWidth * (FS / font.unitsPerEm), bbox, contours: out };
+}
+
+const glyphs = {};
+for (const ch of CHARS) glyphs[ch] = glyphData(ch);
+
+const out = __dirname + '/glyphs.json';
+fs.writeFileSync(out, JSON.stringify({ em: FS, glyphs }));
+console.log('wrote', out, fs.statSync(out).size, 'bytes;', CHARS.length, 'glyphs:', CHARS.join(''));

assets/icons/build/generate.js

@@ -0,0 +1,128 @@
+'use strict';
+// Site icons + the Open Graph card for the public landing, drawn from the same
+// design as ../../vk (the wooden Erudit tile: face «Э», score «8») and the app's
+// board palette (ui/src/app.css). Everything is composed as SVG from the committed
+// glyph outlines (build/extract.js -> glyphs.json), so no font is needed at build
+// time; the PNG/ICO rasters are screenshots taken with the ui package's Playwright
+// chromium (@playwright/test re-exports the browser API). Outputs go straight to
+// ui/public/:
+//   favicon.svg          96 viewBox, transparent, tile + «Э» (the score is illegible small)
+//   favicon.ico          32x32 PNG-in-ICO render of the same
+//   apple-touch-icon.png 180x180 opaque full-bleed tile (iOS masks its own corners)
+//   og-image.png         1200x630 card: tile + wordmark on the board green
+const fs = require('fs');
+const path = require('path');
+
+const G = JSON.parse(fs.readFileSync(path.join(__dirname, 'glyphs.json'), 'utf8'));
+const UI = path.resolve(__dirname, '../../../ui');
+const OUT = path.join(UI, 'public');
+
+// ---- palette (vk loader tile + app.css board tokens) ------------------------
+const FACE = '#D9B978', BORDER = '#B49559', GLYPH = '#1A1A1A';
+const BOARD_DARK = '#2a3330', TEXT = '#e7ece8', TEXT_MUTED = '#cdd6cf';
+
+// ---- glyph outlines -> SVG path data ----------------------------------------
+const r2 = n => Math.round(n * 100) / 100;
+// pathD renders one glyph's contours scaled by sc and translated by (tx, ty).
+function pathD(g, sc, tx, ty) {
+  const pt = (v, d) => `${r2(v[0] * sc + tx + d[0] * sc)} ${r2(v[1] * sc + ty + d[1] * sc)}`;
+  const Z = [0, 0];
+  return g.contours.map(ct => {
+    const n = ct.v.length;
+    let d = `M${pt(ct.v[0], Z)}`;
+    for (let k = 1; k <= n; k++) {
+      const a = k - 1, b = k % n;
+      d += `C${pt(ct.v[a], ct.o[a])} ${pt(ct.v[b], ct.i[b])} ${pt(ct.v[b], Z)}`;
+    }
+    return d + 'Z';
+  }).join('');
+}
+// glyphAt centres a glyph's bbox at (cx, cy) with the given pixel cap height, the
+// same placement rule as the vk loader's glyph(). stroke fattens it slightly.
+function glyphAt(ch, capPx, cx, cy, stroke, colour) {
+  const g = G.glyphs[ch], sc = capPx / g.bbox.h;
+  const d = pathD(g, sc, cx - (g.bbox.x + g.bbox.w / 2) * sc, cy - (g.bbox.y + g.bbox.h / 2) * sc);
+  return `<path d="${d}" fill="${colour}" stroke="${colour}" stroke-width="${r2(stroke)}"/>`;
+}
+// textLine lays out a string on a baseline from the per-glyph advances; capPx sets
+// the capital height (measured on «Э»). Returns the combined path + the width.
+function textLine(str, capPx, x, y, colour) {
+  const sc = capPx / G.glyphs['Э'].bbox.h;
+  let d = '', w = 0;
+  for (const ch of str) {
+    const g = G.glyphs[ch];
+    if (g.contours.length) d += pathD(g, sc, x + w, y);
+    w += g.adv * sc;
+  }
+  return { svg: `<path d="${d}" fill="${colour}"/>`, width: w };
+}
+// tile draws the rounded wooden tile centred at (cx, cy): size px wide/high, with
+// the vk loader's corner (6/52) and rim proportions, «Э» and optionally the «8».
+function tile(cx, cy, size, withScore) {
+  const h = size / 2, rx = size * (6 / 52), rim = size * (1.8 / 52);
+  let s = `<rect x="${r2(cx - h + rim / 2)}" y="${r2(cy - h + rim / 2)}" width="${r2(size - rim)}" height="${r2(size - rim)}" rx="${r2(rx)}" fill="${FACE}" stroke="${BORDER}" stroke-width="${r2(rim)}"/>`;
+  s += glyphAt('Э', size * (32 / 52), cx, cy - size * (1 / 52), size * (1 / 52), GLYPH);
+  if (withScore) s += glyphAt('8', size * (8.5 / 52), cx + size * (19.5 / 52), cy + size * (18.5 / 52), size * (0.5 / 52), GLYPH);
+  return s;
+}
+const svg = (w, h, body) => `<svg xmlns="http://www.w3.org/2000/svg" width="${w}" height="${h}" viewBox="0 0 ${w} ${h}">${body}</svg>`;
+
+// ---- favicon.svg (the committed vector master) -------------------------------
+const favicon = svg(96, 96, tile(48, 48, 88, false)) + '\n';
+
+// ---- apple-touch-icon: opaque full bleed, iOS applies its own corner mask ----
+const appleTouch = svg(180, 180,
+  `<rect width="180" height="180" fill="${FACE}"/>` +
+  `<rect x="8" y="8" width="164" height="164" rx="18" fill="none" stroke="${BORDER}" stroke-width="4"/>` +
+  glyphAt('Э', 100, 90, 88, 3, GLYPH) +
+  glyphAt('8', 26, 146, 142, 1.5, GLYPH));
+
+// ---- og-image: tile + wordmark, centred as one group on the board green ------
+function ogImage() {
+  const W = 1200, H = 630, tileSize = 340, gap = 84;
+  const l1 = textLine('Эрудит', 112, 0, 0, TEXT);
+  const l2 = textLine('Скрэббл — игра в слова', 44, 0, 0, TEXT_MUTED);
+  const textW = Math.max(l1.width, l2.width);
+  const left = (W - (tileSize + gap + textW)) / 2;
+  const tx = left + tileSize + gap;
+  // Two baselines around the vertical centre; the tile centre sits between them.
+  const b1 = 295, b2 = 408;
+  const body =
+    `<rect width="${W}" height="${H}" fill="${BOARD_DARK}"/>` +
+    tile(left + tileSize / 2, H / 2, tileSize, true) +
+    textLine('Эрудит', 112, tx, b1, TEXT).svg +
+    textLine('Скрэббл — игра в слова', 44, tx, b2, TEXT_MUTED).svg;
+  console.log(`og-image: text ${Math.round(textW)}px wide, group left ${Math.round(left)}px`);
+  return svg(W, H, body);
+}
+
+// ---- rasterisation (Playwright chromium from ui/node_modules) ----------------
+async function shoot(page, markup, w, h, transparent) {
+  await page.setViewportSize({ width: w, height: h });
+  await page.setContent(`<body style="margin:0">${markup}</body>`);
+  return page.screenshot({ omitBackground: transparent });
+}
+// icoFromPNG wraps one PNG as a single-entry .ico (ICONDIR + ICONDIRENTRY + PNG).
+function icoFromPNG(png, sizePx) {
+  const h = Buffer.alloc(22);
+  h.writeUInt16LE(0, 0); h.writeUInt16LE(1, 2); h.writeUInt16LE(1, 4); // icon, 1 image
+  h.writeUInt8(sizePx, 6); h.writeUInt8(sizePx, 7);                    // 32x32
+  h.writeUInt16LE(1, 10); h.writeUInt16LE(32, 12);                     // planes, 32bpp
+  h.writeUInt32LE(png.length, 14); h.writeUInt32LE(22, 18);            // size, offset
+  return Buffer.concat([h, png]);
+}
+
+(async () => {
+  fs.writeFileSync(path.join(OUT, 'favicon.svg'), favicon);
+  const { chromium } = require(path.join(UI, 'node_modules', '@playwright/test'));
+  const browser = await chromium.launch();
+  const page = await browser.newPage();
+  const fav32 = await shoot(page, svg(32, 32, tile(16, 16, 29.33, false)), 32, 32, true);
+  fs.writeFileSync(path.join(OUT, 'favicon.ico'), icoFromPNG(fav32, 32));
+  fs.writeFileSync(path.join(OUT, 'apple-touch-icon.png'), await shoot(page, appleTouch, 180, 180, false));
+  fs.writeFileSync(path.join(OUT, 'og-image.png'), await shoot(page, ogImage(), 1200, 630, false));
+  await browser.close();
+  for (const f of ['favicon.svg', 'favicon.ico', 'apple-touch-icon.png', 'og-image.png']) {
+    console.log('wrote', path.join(OUT, f), fs.statSync(path.join(OUT, f)).size, 'bytes');
+  }
+})();

assets/vk/README.md

@@ -0,0 +1,115 @@
+# Erudit — VK loading-screen logo (Lottie)
+
+Animated logo for the **VK app loading screen** (shown before the SPA assets load).
+The Erudit «Э» tile (score `8`) **drops in under gravity, lands with a soft squash —
+its left/right edges bulging into a cushion — then springs back up**, looping. A light
+"glint" is caught at the moment of the bounce.
+
+| File | Purpose |
+|------|---------|
+| `erudit-loader.json` | The Lottie to upload to VK. |
+| `erudit-loader-preview.gif` | Looping preview. Rendered on a green "baize" background **only in the preview** — the real asset has a **transparent** background. |
+| `build/` | The reproducible build pipeline (see *Regenerate*). |
+
+**VK requirements met:** 96×96 px · vector Lottie JSON · ≤ 24 KB (~11 KB) · seamless
+~1.1 s loop · transparent background.
+
+Design reference: a photo of the physical wooden Erudit tile.
+
+---
+
+## How it works
+
+A single flat layer holds the tile — a rounded-rect **face path**, the two glyphs, and
+a thin border — and everything is driven by that layer's transform plus a few colour /
+shape tracks. The anchor sits on the tile's **bottom edge**, so the squash happens
+against the floor.
+
+### Bounce (gravity)
+`position.y` of the bottom edge goes apex → floor → apex with **no dwell** (the apex is
+an instantaneous turn-around). The fall uses a strong **ease-in** (accelerate) and the
+rise a strong **ease-out** (decelerate), so it reads as real gravity. While falling fast
+the tile slightly **stretches** (tall+thin); that is the squash-and-stretch setup.
+
+### Soft cushion (squash)
+On contact the layer **squashes** (scaleY↓, scaleX↑) about the bottom anchor, with a
+touch of skew. Crucially the squash/cushion is **decoupled from the fall speed** — it
+eases in and out *slowly* (`ES`), so the landing feels soft even though the fall is
+fast. The squash is deliberately gentle (≈ 86 % / 112 %).
+
+### The cushion shape (the hard part)
+The face is **not** a plain rounded rect — it is a path whose left/right contour bows
+out into a convex cushion on impact:
+- the rest rounded-rect outline is sampled (fine corner arcs + edge mids), and on impact
+  every point is pushed outward by a smooth **barrel** profile `f(y) = b·(1 − (y/HH)²)`
+  (max at the middle, fading to zero at the top/bottom);
+- so the **whole side — corners included — bows out as one piece**, never just the
+  straight middle;
+- bezier handles are computed as a **chordal spline** (handle length ∝ the adjacent
+  chord), which stays smooth across the uneven corner/edge point spacing. This is what
+  keeps the corner↔cushion junction kink-free — both at rest and fully bulged — which a
+  naïve uniform Catmull-Rom (or moving discrete points with fixed tangents) does not.
+
+### Glint
+At the bounce the face flashes a little lighter (`FACE_GLINT`) and the glyphs warm
+toward brown-red (`BLACK_LIT`), then settle back. A cheap, warm "catch the light".
+
+### Border & background
+The tile carries a thin static **border** a touch darker than the face (`BORDER`) so it
+reads on any background. The **green baize background is added only when rendering the
+preview GIF** — the Lottie itself is transparent.
+
+### Player compatibility
+Only plain 2-D shapes (`ddd:0`) — no 3-D layers, expressions or effects — so every
+Lottie player (lottie-web on the web, rlottie on native) renders it identically.
+
+---
+
+## Glyphs
+
+`Э` (U+042D) and `8` are **real outlines from LiberationSans-Regular** — metric-
+compatible with Arial, matching the game's `--font: system-ui … Arial` stack
+(see `ui/src/app.css`). `build/extract.js` pulls the contours into `build/glyphs.json`
+as Lottie cubic paths; a hair of same-colour stroke adds a touch of weight.
+
+---
+
+## Regenerate
+
+Requirements: Node ≥ 18. `extract.js` additionally needs `opentype.js`
+(`npm i opentype.js`); **`generate.js` has no dependencies**.
+
+```sh
+cd assets/vk
+
+# 1. (optional) re-extract the glyphs — only if you change the font:
+#    default font: /usr/share/fonts/truetype/liberation/LiberationSans-Regular.ttf
+node build/extract.js [/path/to/font.ttf]      # -> build/glyphs.json
+
+# 2. build the animation (reads build/glyphs.json):
+node build/generate.js erudit-loader.json      # -> erudit-loader.json
+
+# 3. (optional) live preview — needs lottie-web (npm i lottie-web):
+node build/build-preview.js erudit-loader.json preview.html
+#    then open preview.html in a browser.
+```
+
+The preview GIF is assembled by rendering the Lottie frame-by-frame (lottie-web canvas,
+filled with the green baize) and stitching with `ffmpeg`; the live HTML preview is the
+quickest way to eyeball changes.
+
+## Tunables (top of `build/generate.js`)
+
+| Symbol | Meaning |
+|--------|---------|
+| `OP`, `FR` | loop length (frames) / fps — overall speed |
+| `T_HIT / T_PEAK / T_LIFT / T_REC` | beats: contact / squash peak / lift-off / cushion recovered |
+| `EI / EO / ES` | easings: fast fall / fast rise / slow soft cushion |
+| `APEX`, `FLOOR` | bottom-edge screen-y at the top of the bounce / at rest |
+| `HW`, `HH`, `CR` | tile half-width / half-height / corner radius |
+| `scl` squash values | the squash amount (scaleX↑ / scaleY↓) |
+| `bulge` `b` | cushion depth (how far the sides bow out) |
+| `FACE / FACE_GLINT` | wood face / glint flash |
+| `BORDER` | tile rim colour |
+| `BLACK / BLACK_LIT` | glyph / glyph-at-glint (brown-red) |
+| preview bg `#3C7858` | the green-baize colour used **only** in the GIF |

assets/vk/build/build-preview.js

@@ -0,0 +1,31 @@
+'use strict';
+const fs = require('fs');
+const data = fs.readFileSync(process.argv[2] || 'erudit.json', 'utf8');
+const lottiePath = __dirname + '/node_modules/lottie-web/build/player/lottie.min.js';
+const html = `<!doctype html><html><head><meta charset="utf8"><style>
+body{margin:0;background:#2b2b2b;font-family:sans-serif;color:#ccc}
+.row{display:flex;gap:18px;padding:18px;align-items:flex-end;flex-wrap:wrap}
+.cell{text-align:center}
+.chk{background-image:linear-gradient(45deg,#8a8a8a 25%,transparent 25%),linear-gradient(-45deg,#8a8a8a 25%,transparent 25%),linear-gradient(45deg,transparent 75%,#8a8a8a 75%),linear-gradient(-45deg,transparent 75%,#8a8a8a 75%);background-size:16px 16px;background-position:0 0,0 8px,8px -8px,-8px 0;background-color:#b5b5b5}
+.s96{width:96px;height:96px}.big{width:336px;height:336px}small{font-size:11px}
+</style></head><body><div class="row" id="row"></div>
+<script src="./lottie.min.js"></script>
+<script>
+const animationData=${data};window.AD=animationData;
+const row=document.getElementById('row');window.anims=[];
+function make(cls,frame,label){
+  const cell=document.createElement('div');cell.className='cell';
+  const box=document.createElement('div');box.className='chk '+cls;cell.appendChild(box);
+  cell.appendChild(document.createElement('br'));
+  const cap=document.createElement('small');cap.textContent=label;cell.appendChild(cap);
+  row.appendChild(cell);
+  const a=lottie.loadAnimation({container:box,renderer:'svg',loop:false,autoplay:false,animationData:JSON.parse(JSON.stringify(animationData))});
+  a.addEventListener('DOMLoaded',()=>a.goToAndStop(frame,true));
+  window.anims.push(a);
+}
+[0,22,45,68].forEach(f=>make('s96',f,'f'+f));
+make('big',22,'f22 x3.5');
+window.__ready=true;
+</script></body></html>`;
+fs.writeFileSync(process.argv[3] || 'preview.html', html);
+console.log('wrote', process.argv[3] || 'preview.html');

assets/vk/build/extract.js

@@ -0,0 +1,67 @@
+'use strict';
+// Extract the Cyrillic "Э" (U+042D) and the digit "8" outlines from a grotesque
+// font (LiberationSans = Arial-metric, matching the game's system-ui/Arial stack)
+// and emit Lottie cubic-bezier contours, centred at the origin, y-down.
+const opentype = require('opentype.js');
+const fs = require('fs');
+
+const FONT = process.argv[2] || '/usr/share/fonts/truetype/liberation/LiberationSans-Regular.ttf';
+const b = fs.readFileSync(FONT);
+const font = opentype.parse(b.buffer.slice(b.byteOffset, b.byteOffset + b.byteLength));
+const FS = 1000; // em scale
+
+function glyphContours(ch) {
+  const p = font.charToGlyph(ch).getPath(0, 0, FS); // baseline at y=0, y-down
+  const contours = [];
+  let cur = null, prev = null;
+  for (const c of p.commands) {
+    if (c.type === 'M') {
+      if (cur) contours.push(cur);
+      cur = [{ v: [c.x, c.y], i: [c.x, c.y], o: [c.x, c.y] }];
+      prev = { x: c.x, y: c.y };
+    } else if (c.type === 'L') {
+      cur.push({ v: [c.x, c.y], i: [c.x, c.y], o: [c.x, c.y] });
+      prev = { x: c.x, y: c.y };
+    } else if (c.type === 'C') {
+      cur[cur.length - 1].o = [c.x1, c.y1];
+      cur.push({ v: [c.x, c.y], i: [c.x2, c.y2], o: [c.x, c.y] });
+      prev = { x: c.x, y: c.y };
+    } else if (c.type === 'Q') {
+      const c1 = [prev.x + 2 / 3 * (c.x1 - prev.x), prev.y + 2 / 3 * (c.y1 - prev.y)];
+      const c2 = [c.x + 2 / 3 * (c.x1 - c.x), c.y + 2 / 3 * (c.y1 - c.y)];
+      cur[cur.length - 1].o = c1;
+      cur.push({ v: [c.x, c.y], i: c2, o: [c.x, c.y] });
+      prev = { x: c.x, y: c.y };
+    } else if (c.type === 'Z') {
+      if (cur && cur.length > 1) {
+        const last = cur[cur.length - 1], first = cur[0];
+        if (Math.hypot(last.v[0] - first.v[0], last.v[1] - first.v[1]) < 1e-3) {
+          first.i = last.i;            // fold the duplicate closing point into the first
+          cur.pop();
+        }
+      }
+      if (cur) { contours.push(cur); cur = null; }
+    }
+  }
+  if (cur) contours.push(cur);
+
+  let minx = Infinity, miny = Infinity, maxx = -Infinity, maxy = -Infinity;
+  const out = contours.map(ct => {
+    const v = [], i = [], o = [];
+    ct.forEach(pt => {
+      v.push(pt.v);
+      i.push([pt.i[0] - pt.v[0], pt.i[1] - pt.v[1]]);
+      o.push([pt.o[0] - pt.v[0], pt.o[1] - pt.v[1]]);
+      minx = Math.min(minx, pt.v[0]); maxx = Math.max(maxx, pt.v[0]);
+      miny = Math.min(miny, pt.v[1]); maxy = Math.max(maxy, pt.v[1]);
+    });
+    return { i, o, v, c: true };
+  });
+  return { contours: out, bbox: { x: minx, y: miny, w: maxx - minx, h: maxy - miny } };
+}
+
+const E = glyphContours('Э');
+const D8 = glyphContours('8');
+fs.writeFileSync('glyphs.json', JSON.stringify({ em: FS, E, D8 }));
+console.log('Э bbox', E.bbox, 'contours', E.contours.map(c => c.v.length));
+console.log('8 bbox', D8.bbox, 'contours', D8.contours.map(c => c.v.length));

assets/vk/build/generate.js

@@ -0,0 +1,153 @@
+'use strict';
+// VK preloader Lottie: a flat wooden Erudit tile ("Э" + score "8") that drops in
+// under gravity, squashes on impact (convex cushion bulging out the left/right edges
+// + a touch of skew), and springs back up — looping. A light "glint" is caught at the
+// moment of the bounce. Pure 2D shapes (ddd:0). Glyphs are real LiberationSans
+// outlines (Arial-metric, = the game's font stack); see extract.js -> glyphs.json.
+const fs = require('fs');
+const G = JSON.parse(fs.readFileSync(__dirname + '/glyphs.json', 'utf8'));
+
+// ---- canvas / timing -------------------------------------------------------
+const W = 96, H = 96, cx = 48;
+const FR = 30, OP = 34;                      // ~1.13 s loop (dynamic, 25% faster)
+// keyframe beats (frames): fast fall -> soft squash -> lift -> fast rise -> apex (no dwell)
+const T_HIT = 13, T_PEAK = 18, T_LIFT = 19, T_REC = 28;
+
+// ---- geometry --------------------------------------------------------------
+const HW = 26, HH = 26, CR = 6;              // tile half-width / half-height / corner radius
+const FLOOR = 90, APEX = 60;                 // bottom-centre screen-y at rest / at the top of the bounce
+
+// ---- palette ---------------------------------------------------------------
+const col = h => [parseInt(h.slice(1,3),16)/255, parseInt(h.slice(3,5),16)/255, parseInt(h.slice(5,7),16)/255];
+const FACE = col('#D9B978');                 // wood face (flat)
+const FACE_GLINT = col('#E7CD95');           // face flash caught on impact (gentle, not blinding)
+const BORDER = col('#B49559');               // tile rim: a touch darker than the face, reads on any bg
+const BLACK = col('#1A1A1A');
+const BLACK_LIT = col('#421A0B');            // glyph warms to brown-red on the glint
+const lerp = (a, b, t) => a.map((v, i) => v + (b[i] - v) * t);
+
+// ---- property / easing helpers ---------------------------------------------
+const still = v => ({ a: 0, k: v });
+const EI = { o: { x: [0.82], y: [0] }, i: { x: [1], y: [1] } };  // strong accelerate (gravity fall)
+const EO = { o: { x: [0], y: [0] }, i: { x: [0.18], y: [1] } };  // strong decelerate (rise to apex)
+const ES = { o: { x: [0.42], y: [0] }, i: { x: [0.58], y: [1] } }; // soft/slow (the cushion)
+function anim(samples) {                      // samples: {t, v, e?} ; e = easing toward the NEXT key
+  return { a: 1, k: samples.map((s, idx) => {
+    const kf = { t: s.t, s: s.v };
+    if (idx < samples.length - 1) { const e = s.e || ES; kf.o = e.o; kf.i = e.i; }
+    return kf;
+  }) };
+}
+const animColor = s => anim(s.map(x => ({ t: x.t, v: [...x.v, 1], e: x.e })));
+
+// ---- shape helpers ---------------------------------------------------------
+const tr = () => ({ ty: 'tr', p: still([0,0]), a: still([0,0]), s: still([100,100]), r: still(0), o: still(100) });
+const grp = (items, nm) => ({ ty: 'gr', it: [...items, tr()], nm });
+const fill = c => ({ ty: 'fl', c, o: still(100), r: 1, bm: 0 });
+const stroke = (c,w) => ({ ty: 'st', c: still(c), o: still(100), w: still(w), lc: 2, lj: 2, ml: 4, bm: 0 });
+function glyph(gd, hpx, px, py, bold, colour, nm) {  // font glyph -> filled+stroked group
+  const sc = hpx / gd.bbox.h;
+  const bcx = gd.bbox.x + gd.bbox.w / 2, bcy = gd.bbox.y + gd.bbox.h / 2;
+  const shapes = gd.contours.map(ct => ({
+    ty: 'sh', d: 1, ks: still({
+      i: ct.i.map(p => [p[0]*sc, p[1]*sc]), o: ct.o.map(p => [p[0]*sc, p[1]*sc]),
+      v: ct.v.map(p => [(p[0]-bcx)*sc + px, (p[1]-bcy)*sc + py]), c: true,
+    }),
+  }));
+  return grp([...shapes, fill(colour), stroke(BLACK, bold)], nm);
+}
+
+// Sample the rest rounded-rect outline (clockwise): fine corner arcs + one mid point
+// per straight edge, so a smooth interpolant reproduces it cleanly.
+function arc(ccx, ccy, a0, a1, n) {
+  const out = [];
+  for (let i = 0; i < n; i++) { const a = (a0 + (a1 - a0) * i / (n - 1)) * Math.PI / 180; out.push([ccx + CR*Math.cos(a), ccy + CR*Math.sin(a)]); }
+  return out;
+}
+const REST = (() => {
+  const NC = 7, yi = HH - CR, xi = HW - CR;
+  const C = [ arc(xi,-yi,-90,0,NC), arc(xi,yi,0,90,NC), arc(-xi,yi,90,180,NC), arc(-xi,-yi,180,270,NC) ];
+  const pts = [];
+  for (let k = 0; k < 4; k++) {
+    pts.push(...C[k]);
+    const a = C[k][NC-1], b = C[(k+1)%4][0];
+    pts.push([(a[0]+b[0])/2, (a[1]+b[1])/2]);   // straight-edge mid point (keeps the edge straight)
+  }
+  return pts;
+})();
+// The whole left/right contour (corners + side) bows out by one smooth barrel profile;
+// Catmull-Rom tangents (from neighbours) make every junction C1-smooth -> no kink, the
+// corners follow the cushion and the cushion melts into the corners, bulged or not.
+function facePath(b) {
+  const f = y => b * (1 - (y/HH) * (y/HH));                       // 0 at top/bottom, max at the middle
+  const V = REST.map(([x, y]) => [x + Math.sign(x) * f(y), y]);   // push the sides out, top/bottom stay
+  const n = V.length, I = [], O = [];
+  for (let k = 0; k < n; k++) {
+    const p0 = V[(k-1+n)%n], p1 = V[k], p2 = V[(k+1)%n];
+    let dx = p2[0]-p0[0], dy = p2[1]-p0[1];                       // tangent direction (neighbours)
+    const dl = Math.hypot(dx, dy) || 1; dx /= dl; dy /= dl;
+    const ln = Math.hypot(p2[0]-p1[0], p2[1]-p1[1]) / 3;          // handles ~ 1/3 of the adjacent chord
+    const lp = Math.hypot(p1[0]-p0[0], p1[1]-p0[1]) / 3;          // -> chordal spline, no overshoot/facets
+    O.push([dx*ln, dy*ln]); I.push([-dx*lp, -dy*lp]);
+  }
+  return { i: I, o: O, v: V, c: true };
+}
+const facePathKeys = samples => ({ a: 1, k: samples.map((s, idx) => {
+  const kf = { t: s.t, s: [facePath(s.b)] };
+  if (idx < samples.length - 1) { const e = s.e || ES; kf.o = e.o; kf.i = e.i; }
+  return kf;
+}) });
+
+// ---- animation tracks ------------------------------------------------------
+// bottom-centre screen-y (the tile rests/squashes on its bottom edge)
+const posY = anim([
+  { t: 0,      v: [cx, APEX, 0],  e: EI },           // apex -> immediately falls (no dwell)
+  { t: T_HIT,  v: [cx, FLOOR, 0], e: ES },           // FAST fall (accelerate) -> floor
+  { t: T_LIFT, v: [cx, FLOOR, 0], e: EO },           // sit on the floor while the cushion absorbs
+  { t: OP,     v: [cx, APEX, 0] },                   // FAST rise (decelerate) -> apex = loop start
+]);
+// scale about the bottom anchor: stretch while falling, gentle/slow cushion squash on impact
+const scl = anim([
+  { t: 0,        v: [100, 100, 100], e: ES },
+  { t: T_HIT-5,  v: [95, 106, 100], e: ES },         // stretch while falling fast
+  { t: T_HIT,    v: [104, 95, 100], e: ES },         // touch down
+  { t: T_PEAK,   v: [112, 86, 100], e: ES },         // soft squash peak (gentler, less plче)
+  { t: T_REC,    v: [100, 100, 100], e: ES },        // slow cushion release -> soft landing
+  { t: OP,       v: [100, 100, 100] },
+]);
+// a touch of skew through the squash (organic deform), back to 0
+const skw = anim([
+  { t: T_HIT, v: [0], e: ES }, { t: T_PEAK, v: [4], e: ES }, { t: T_REC, v: [0] }, { t: OP, v: [0] },
+]);
+// left/right cushion bulge: 0 -> gentle peak -> 0 (never inward)
+const bulge = facePathKeys([
+  { t: T_HIT, b: 0, e: ES }, { t: T_PEAK, b: 4, e: ES }, { t: T_REC, b: 0 }, { t: OP, b: 0 },
+]);
+// glint: face + glyph catch the light at the bounce
+const faceCol = animColor([
+  { t: T_HIT-2, v: FACE, e: ES }, { t: T_PEAK, v: FACE_GLINT, e: ES }, { t: T_REC, v: FACE }, { t: OP, v: FACE },
+]);
+const glyphCol = animColor([
+  { t: T_HIT-2, v: BLACK, e: ES }, { t: T_PEAK, v: BLACK_LIT, e: ES }, { t: T_REC, v: BLACK }, { t: OP, v: BLACK },
+]);
+
+// ---- layer (face + glyphs share the bounce/squash transform) ---------------
+const faceShape = grp([ { ty: 'sh', d: 1, ks: bulge }, fill(faceCol), stroke(BORDER, 1.8) ], 'face');
+const glyphE = glyph(G.E,  32, 0, -1, 1.0, glyphCol, 'E');                 // centred Э
+const glyph8 = glyph(G.D8, 8.5, HW-6.5, HH-7.5, 0.5, glyphCol, 'score');   // 8 in the corner
+
+const tile = {
+  ddd: 0, ind: 1, ty: 4, nm: 'tile', sr: 1,
+  ks: { o: still(100), r: still(0), p: posY, a: still([0, HH, 0]), s: scl, sk: skw, sa: still(0) },
+  ao: 0, shapes: [ glyph8, glyphE, faceShape ], ip: 0, op: OP, st: 0, bm: 0,
+};
+
+const root = {
+  v: '5.7.4', fr: FR, ip: 0, op: OP, w: W, h: H, nm: 'erudit-vk-loader', ddd: 0,
+  assets: [], layers: [ tile ], markers: [],
+};
+
+const out = process.argv[2] || 'erudit.json';
+const round = (k, v) => (typeof v === 'number' ? Math.round(v * 100) / 100 : v);
+fs.writeFileSync(out, JSON.stringify(root, round));
+console.log('wrote', out, fs.statSync(out).size, 'bytes');

backend/README.md

@@ -43,8 +43,10 @@ per-user blocks, and per-game chat with nudges folded in as a message kind; chat
 messages are length-capped, content-filtered (no links/emails/phone numbers,
 including obfuscated forms) and stored with the sender's IP. Each message carries an
 `unread_seats` read bitmask (a set bit per recipient seat still to read it); `MarkRead`
-clears a reader's bit when they open the move history or chat, and a wired `NudgeClearer`
-clears a nudge when its recipient moves — both record the publish-to-read latency.
+clears a reader's bit when they open the move history or chat, a wired `NudgeClearer`
+clears a nudge when its recipient moves, and a wired `NudgeExpirer` clears **all** of a game's
+nudges when it finishes (any completion path) — the first two record the publish-to-read latency,
+the completion expiry does not (it is not a read); chat messages stay unread on completion.
 A friend request (or block) aimed at a **disguised pooled robot** is recorded per game+seat
 in `robot_friend_requests` / `robot_blocks`, never against the shared robot account; a
 background reaper drops a robot friend request once its game has been finished for **7 days**.
@@ -98,7 +100,10 @@ state, lobby enqueue, chat). The social/account/history operations under
 `/api/v1/user`: `friends/*` (request/respond/cancel/unfriend,
 list/incoming, the one-time `code` issue/redeem), `blocks/*`, `invitations/*`
 (create/accept/decline/cancel/list), `PUT profile`, `email/{request,confirm}`,
-`stats`, and `games/:id/gcg` (finished-only). The `internal/notify` hub feeds a
+`stats`, `games/:id/gcg` (finished-only), and the payments `wallet` /
+`wallet/catalog` (`GET` — the context-visible chip segments + benefits, and the
+storefront catalog) / `wallet/buy` (`POST` — a chip spend on a value), served by
+`internal/payments` behind the store-compliance gate. The `internal/notify` hub feeds a
 second listener — `internal/pushgrpc`, a gRPC server (`BACKEND_GRPC_ADDR`) streaming
 live events (your-turn, opponent-moved, chat, nudge, match-found, notify) to the
 gateway. The gateway-only `POST /api/v1/internal/push-target` (a user's
@@ -212,11 +217,13 @@ internal/banview/    # gateway active-ban mirror: the console's Active IP bans p
 | `BACKEND_LOBBY_ROBOT_WAIT` | `10s` | Auto-match wait before a robot is substituted for a missing human. |
 | `BACKEND_LOBBY_REAPER_INTERVAL` | `1s` | How often the substitution reaper scans for over-waited players. |
 | `BACKEND_ROBOT_DRIVE_INTERVAL` | `30s` | How often the robot driver scans for due robot turns. |
-| `BACKEND_SMTP_HOST` | — | Email relay host. **Empty selects the development log mailer** (the confirm-code is logged, not sent). |
-| `BACKEND_SMTP_PORT` | `587` | Email relay port. |
-| `BACKEND_SMTP_USERNAME` | — | SMTP user; empty relays without authentication. |
-| `BACKEND_SMTP_PASSWORD` | — | SMTP password. |
-| `BACKEND_SMTP_FROM` | `no-reply@localhost` | Envelope/From address for confirm-codes. |
+| `BACKEND_SMTP_HOST` | — | Confirm-code relay host. **Empty selects the development log mailer** (the code is logged, not sent). |
+| `BACKEND_SMTP_PORT` | `587` | Relay port. No client certificate is needed (the server cert is validated against the system roots). |
+| `BACKEND_SMTP_TLS` | — | Transport security: `ssl` (implicit TLS from connect) or `starttls`. Empty derives it from the port (implicit on `465`, STARTTLS otherwise); set it for a relay on a non-standard port (e.g. Selectel's `1127` = SSL, `1126` = STARTTLS). |
+| `BACKEND_SMTP_USERNAME` | — | SMTP AUTH user; empty relays without authentication. |
+| `BACKEND_SMTP_PASSWORD` | — | SMTP AUTH password. |
+| `BACKEND_SMTP_FROM` | `no-reply@localhost` | From address. A deployed contour must use the prod domain (the relay only accepts its verified sender domain). |
+| `BACKEND_PUBLIC_BASE_URL` | — | Canonical public origin (scheme + host) for links in the email. **Required when `BACKEND_SMTP_HOST` is set.** Never derived from a request Host header (anti-injection). |
 | `BACKEND_CONNECTOR_ADDR` | — | the gateway bot-link relay gRPC address for admin-console operator broadcasts. Empty disables broadcasts. |
 | `BACKEND_GUEST_REAP_INTERVAL` | `1h` | How often the abandoned-guest reaper sweeps. |
 | `BACKEND_GUEST_RETENTION` | `720h` | Account age past which a guest with no game seat is deleted. |

backend/cmd/backend/main.go

@@ -20,6 +20,7 @@ import (
 
 	"scrabble/backend/internal/account"
 	"scrabble/backend/internal/accountmerge"
+	"scrabble/backend/internal/adminalert"
 	"scrabble/backend/internal/ads"
 	"scrabble/backend/internal/banview"
 	"scrabble/backend/internal/config"
@@ -30,9 +31,11 @@ import (
 	"scrabble/backend/internal/link"
 	"scrabble/backend/internal/lobby"
 	"scrabble/backend/internal/notify"
+	"scrabble/backend/internal/payments"
 	"scrabble/backend/internal/postgres"
 	"scrabble/backend/internal/pushgrpc"
 	"scrabble/backend/internal/ratewatch"
+	"scrabble/backend/internal/render"
 	"scrabble/backend/internal/robot"
 	"scrabble/backend/internal/server"
 	"scrabble/backend/internal/session"
@@ -43,6 +46,10 @@ import (
 // telemetryShutdownTimeout bounds the OpenTelemetry flush during process exit.
 const telemetryShutdownTimeout = 5 * time.Second
 
+// adminAlertInterval is how often the operator-alert worker checks for new feedback /
+// complaints; a burst within one interval coalesces into a single digest email.
+const adminAlertInterval = 5 * time.Minute
+
 func main() {
 	cfg, err := config.Load()
 	if err != nil {
@@ -161,6 +168,15 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 		zap.Duration("interval", cfg.GuestReapInterval),
 		zap.Duration("retention", cfg.GuestRetention))
 
+	// Purge the account-deletion legal dossier past its retention TTL: the
+	// retained-identities journal, and the feedback thread + dossier PII of long-deleted
+	// accounts (chat is kept). Checked daily; the TTL is a two-year policy constant.
+	retentionReaper := account.NewRetentionReaper(accounts, account.RetentionTTL, logger)
+	go retentionReaper.Run(ctx, 24*time.Hour)
+	logger.Info("retention reaper started",
+		zap.Duration("interval", 24*time.Hour),
+		zap.Duration("retention", account.RetentionTTL))
+
 	// Re-evaluate moderated-chat write access when a temporary block self-expires:
 	// no operator action fires then, so the sweeper emits the chat-access-changed
 	// event for lapsed blocks and the gateway re-pushes the chat-gate command.
@@ -173,15 +189,21 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 	// Lobby & social domains. Their REST and stream surface lives in the gateway,
 	// so they are handed to the server (like the route groups) for the handlers.
 	mailer := newMailer(cfg.SMTP, logger)
-	emails := account.NewEmailService(accounts, mailer)
+	emails := account.NewEmailService(accounts, mailer, cfg.PublicBaseURL)
+	// Throttle confirm-code sends per recipient: at most one per minute and five per
+	// rolling hour, guarding against email bombing and the relay's own quota.
+	emails.SetSendLimiter(account.NewSendLimiter(time.Minute, 5))
 	// Account linking & merge: the orchestrator over the account, merge and
 	// session layers. Wired to the /api/v1/user/link REST surface below.
-	links := link.NewService(emails, accounts, accountmerge.NewMerger(db), sessions)
+	merger := accountmerge.NewMerger(db)
+	links := link.NewService(emails, accounts, merger, sessions)
 	socialSvc := social.NewService(social.NewStore(db), accounts, games)
 	socialSvc.SetNotifier(hub)
 	socialSvc.SetMetrics(tel.MeterProvider().Meter("scrabble/backend/social"))
-	// A nudge the recipient answered by moving is marked read on the move path.
+	// A nudge the recipient answered by moving is marked read on the move path; every nudge in a
+	// game is marked read when the game finishes (a stale badge), on any completion path.
 	games.SetNudgeClearer(socialSvc.ClearNudges)
+	games.SetNudgeExpirer(socialSvc.ExpireNudges)
 	// Reap per-game disguised-robot friend requests once their game is long finished
 	// (the robot ignores them; the row only pins the in-game "request sent" state).
 	robotReqReaper := social.NewRobotFriendRequestReaper(socialSvc, logger)
@@ -192,6 +214,16 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 	feedbackSvc := feedback.NewService(feedback.NewStore(db), accounts)
 	feedbackSvc.SetNotifier(hub)
 
+	// Operator alert emails on new feedback / word complaints, coalesced into one digest
+	// per interval. Inert unless a distinct admin sender and recipient are configured.
+	if cfg.SMTP.AdminFrom != "" && cfg.SMTP.AdminTo != "" {
+		// The alert digest carries no admin-console link on purpose — an admin URL must not
+		// travel in an email (a mail provider could cache or index it); see adminalert.New.
+		alerts := adminalert.New(mailer, feedbackSvc, games, cfg.SMTP.AdminFrom, cfg.SMTP.AdminTo, logger)
+		go alerts.Run(ctx, adminAlertInterval)
+		logger.Info("admin alert worker started", zap.Duration("interval", adminAlertInterval))
+	}
+
 	// Robot opponent: provision its durable account pool (a hard startup
 	// dependency, like the dictionaries) and start its move driver. The matchmaker
 	// substitutes a pooled robot for a missing human after the wait window.
@@ -230,6 +262,28 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 	// block and the banner admin console section.
 	adsSvc := ads.NewService(ads.NewStore(db))
 
+	// In-game currency domain (data foundation): the payments schema behind a
+	// narrow interface. A boot-time reachability check fails fast if the schema
+	// did not migrate; the wallet routes are registered when that surface lands.
+	paymentsSvc := payments.NewService(payments.NewStore(db))
+	if err := paymentsSvc.Ping(ctx); err != nil {
+		return fmt.Errorf("payments schema unreachable: %w", err)
+	}
+	logger.Info("payments domain ready")
+
+	// Wire the payments surface into the domains that consume it: the online-game hint wallet
+	// and the account-merge wallet fold. Done after the reachability check so a broken payments
+	// schema fails boot before anything depends on it.
+	games.SetHintWallet(paymentsSvc)
+	merger.SetPayments(paymentsSvc)
+
+	// The image-render sidecar client for the PNG export artifact; nil (PNG
+	// download answers 404) when BACKEND_RENDERER_URL is unset.
+	var renderer *render.Client
+	if cfg.RendererURL != "" {
+		renderer = render.New(cfg.RendererURL)
+	}
+
 	srv := server.New(cfg.HTTPAddr, server.Deps{
 		Logger:        logger,
 		DB:            db,
@@ -250,7 +304,10 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 		RateWatch:     rateWatch,
 		BanView:       banView,
 		Ads:           adsSvc,
+		Payments:      paymentsSvc,
 		Notifier:      hub,
+		ExportSignKey: cfg.ExportSignKey,
+		Renderer:      renderer,
 	})
 	pushSrv := pushgrpc.NewServer(cfg.GRPCAddr, hub, logger)
 

backend/cmd/dictgen/main.go

@@ -0,0 +1,193 @@
+// Command dictgen dumps golden parity vectors from the committed dawg
+// dictionaries so the TypeScript dawg reader can be checked byte-for-byte
+// against the authoritative Go dafsa reader.
+//
+// For each *.dawg file it writes, into the output directory:
+//
+//   - <name>.words.bin — every stored word as alphabet-index bytes, in index
+//     order, framed as [1-byte length][length index bytes]. The word at stream
+//     position k has IndexOfB == k.
+//   - <name>.neg.bin — negative lookups (sequences whose IndexOfB is -1), same
+//     framing, to exercise the not-found path at varying depths.
+//   - <name>.meta.json — NumAdded/NumNodes/NumEdges plus the alphabet size, for
+//     a header-parse sanity cross-check on the TS side.
+//
+// It is a development tool (not built into any service), analogous to
+// cmd/jetgen. Run it from the repository root:
+//
+//	go run ./backend/cmd/dictgen -dawg-dir ../scrabble-solver/dawg -out <dir>
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"math/rand"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	dawg "github.com/iliadenisov/dafsa"
+)
+
+// meta is the per-dictionary sanity payload cross-checked by the TS reader.
+type meta struct {
+	NumAdded int `json:"numAdded"`
+	NumNodes int `json:"numNodes"`
+	NumEdges int `json:"numEdges"`
+	Alphabet int `json:"alphabet"`
+}
+
+func main() {
+	dawgDir := flag.String("dawg-dir", "../scrabble-solver/dawg", "directory holding the .dawg files")
+	outDir := flag.String("out", "", "output directory for the golden files (required)")
+	negCount := flag.Int("neg", 20000, "number of negative lookups to emit per dictionary")
+	flag.Parse()
+
+	if *outDir == "" {
+		fail("-out is required")
+	}
+	if err := os.MkdirAll(*outDir, 0o755); err != nil {
+		fail("mkdir out: %v", err)
+	}
+
+	files, err := filepath.Glob(filepath.Join(*dawgDir, "*.dawg"))
+	if err != nil {
+		fail("glob: %v", err)
+	}
+	sort.Strings(files)
+	if len(files) == 0 {
+		fail("no .dawg files in %s", *dawgDir)
+	}
+
+	for _, f := range files {
+		if err := process(f, *outDir, *negCount); err != nil {
+			fail("%s: %v", filepath.Base(f), err)
+		}
+	}
+}
+
+// process emits the golden files for a single dawg dictionary.
+func process(path, outDir string, negCount int) error {
+	name := strings.TrimSuffix(filepath.Base(path), ".dawg")
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return err
+	}
+	finder, err := dawg.Read(bytes.NewReader(data), 0)
+	if err != nil {
+		return fmt.Errorf("read dawg: %w", err)
+	}
+	defer finder.Close()
+
+	// Stream every stored word in index order; keep a decimated sample and the
+	// maximum alphabet index for negative generation.
+	wf, err := os.Create(filepath.Join(outDir, name+".words.bin"))
+	if err != nil {
+		return err
+	}
+	bw := bufio.NewWriter(wf)
+
+	var (
+		count  int
+		maxIx  byte
+		sample [][]byte
+	)
+	finder.EnumerateB(func(index int, word []byte, final bool) int {
+		if !final {
+			return 0 // Continue
+		}
+		if index != count {
+			panic(fmt.Sprintf("%s: enumerate index gap: got %d want %d", name, index, count))
+		}
+		writeWord(bw, word)
+		for _, b := range word {
+			if b > maxIx {
+				maxIx = b
+			}
+		}
+		if count%4 == 0 && len(sample) < 60000 {
+			sample = append(sample, append([]byte(nil), word...))
+		}
+		count++
+		return 0 // Continue
+	})
+	if err := bw.Flush(); err != nil {
+		return err
+	}
+	if err := wf.Close(); err != nil {
+		return err
+	}
+	if count != finder.NumAdded() {
+		return fmt.Errorf("word count %d != NumAdded %d", count, finder.NumAdded())
+	}
+
+	alphabet := int(maxIx) + 1
+
+	// Negatives: mutate sampled real words and keep the ones the reader rejects.
+	nf, err := os.Create(filepath.Join(outDir, name+".neg.bin"))
+	if err != nil {
+		return err
+	}
+	nbw := bufio.NewWriter(nf)
+	rng := rand.New(rand.NewSource(1))
+	neg := 0
+	for neg < negCount && len(sample) > 0 {
+		base := sample[rng.Intn(len(sample))]
+		cand := append([]byte(nil), base...)
+		switch rng.Intn(3) {
+		case 0: // extend by one index
+			cand = append(cand, byte(rng.Intn(alphabet)))
+		case 1: // flip one index
+			if len(cand) > 0 {
+				cand[rng.Intn(len(cand))] = byte(rng.Intn(alphabet))
+			}
+		case 2: // drop the tail and flip the new last index
+			if len(cand) > 1 {
+				cand = cand[:len(cand)-1]
+				cand[len(cand)-1] = byte(rng.Intn(alphabet))
+			}
+		}
+		if finder.IndexOfB(cand) == -1 {
+			writeWord(nbw, cand)
+			neg++
+		}
+	}
+	if err := nbw.Flush(); err != nil {
+		return err
+	}
+	if err := nf.Close(); err != nil {
+		return err
+	}
+
+	m := meta{NumAdded: finder.NumAdded(), NumNodes: finder.NumNodes(), NumEdges: finder.NumEdges(), Alphabet: alphabet}
+	mb, err := json.MarshalIndent(m, "", "  ")
+	if err != nil {
+		return err
+	}
+	if err := os.WriteFile(filepath.Join(outDir, name+".meta.json"), mb, 0o644); err != nil {
+		return err
+	}
+
+	fmt.Printf("%-12s words=%d negatives=%d alphabet=%d nodes=%d edges=%d\n",
+		name, count, neg, alphabet, finder.NumNodes(), finder.NumEdges())
+	return nil
+}
+
+// writeWord frames one index-byte word as [length][bytes].
+func writeWord(w *bufio.Writer, word []byte) {
+	if len(word) > 255 {
+		panic(fmt.Sprintf("word too long to frame: %d", len(word)))
+	}
+	w.WriteByte(byte(len(word)))
+	w.Write(word)
+}
+
+func fail(format string, args ...any) {
+	fmt.Fprintf(os.Stderr, "dictgen: "+format+"\n", args...)
+	os.Exit(1)
+}

backend/cmd/jetgen/main.go

@@ -9,7 +9,8 @@
 //  1. start a postgres:17-alpine container via testcontainers-go
 //  2. open it with search_path=backend and apply the embedded goose migrations
 //  3. drop goose's bookkeeping table so jet does not generate a model for it
-//  4. run jet's PostgreSQL generator for schema=backend into internal/postgres/jet
+//  4. run jet's PostgreSQL generator for the backend and payments schemas into
+//     internal/postgres/jet (one subdirectory per schema)
 package main
 
 import (
@@ -36,6 +37,7 @@ const (
 	superuserPassword  = "scrabble"
 	superuserDatabase  = "scrabble_backend"
 	backendSchema      = "backend"
+	paymentsSchema     = "payments"
 	containerStartup   = 90 * time.Second
 	jetOutputDirSuffix = "internal/postgres/jet"
 )
@@ -105,11 +107,16 @@ func run(ctx context.Context) error {
 		return fmt.Errorf("drop goose_db_version: %w", err)
 	}
 
-	if err := jetpostgres.GenerateDB(db, backendSchema, outputDir); err != nil {
-		return fmt.Errorf("jet generate: %w", err)
+	// Each schema generates into its own jet/<schema>/ subdirectory (the
+	// generator wipes only that subtree), so the two calls do not clobber each
+	// other. GenerateDB takes the schema explicitly, so the connection's
+	// search_path=backend does not affect the payments introspection.
+	for _, schema := range []string{backendSchema, paymentsSchema} {
+		if err := jetpostgres.GenerateDB(db, schema, outputDir); err != nil {
+			return fmt.Errorf("jet generate schema=%s: %w", schema, err)
+		}
+		log.Printf("jetgen: generated jet code into %s (schema=%s)", outputDir, schema)
 	}
-
-	log.Printf("jetgen: generated jet code into %s (schema=%s)", outputDir, backendSchema)
 	return nil
 }
 

backend/cmd/movegen/main.go

@@ -0,0 +1,417 @@
+// Command movegen emits golden conformance fixtures for the client-side move
+// generator port (ui/src/lib/dict). It is a dev tool, run by hand; its output is
+// committed so the TypeScript parity tests run without a Go toolchain.
+//
+// For each small sample dictionary (English and Russian — the latter reaches
+// alphabet index 32, exercising the 33-letter cross-set boundary) it writes:
+//
+//   - sample_<tag>.dawg           the serialized dictionary (the reader/cursor fixture)
+//   - sample_<tag>.words.json     the stored words + their alphabet indexes
+//   - sample_<tag>.gen.json       ranked move-generation results from the real solver,
+//     for a handful of positions, plus the ruleset the TS
+//     side rebuilds to score identically
+//
+// Positions are built with only the solver's public API: an empty board, and
+// two-ply positions reached by applying the solver's own top move (so no internal
+// encoding is needed). Regenerate with:
+//
+//	go run ./backend/cmd/movegen -out ui/src/lib/dict/testdata
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"flag"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"gitea.iliadenisov.ru/developer/scrabble-solver/board"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/rack"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/rules"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/scrabble"
+	dawg "github.com/iliadenisov/dafsa"
+)
+
+// sampleWordsEN is the English sample dictionary, in strictly increasing
+// alphabet-index order (the builder requires it). Shared prefixes (car/care/cars),
+// shared suffixes (cats/dogs), internal-final nodes (do, an) and a one-letter word.
+var sampleWordsEN = []string{
+	"a", "an", "and", "ant",
+	"car", "care", "cared", "cares", "cars", "cat", "cats",
+	"do", "doe", "does", "dog", "dogs", "done", "dot",
+}
+
+// sampleWordsRU is the Russian sample dictionary, in strictly increasing index
+// order. It deliberately includes words starting with я (index 32) so the ported
+// cross-set handles alphabet indexes past JS's 31-bit shift boundary.
+var sampleWordsRU = []string{"ад", "ар", "оса", "я", "яд", "яр"}
+
+// sampleFixture is the JSON committed with the .dawg so the TypeScript cursor test
+// knows the exact word set (as alphabet indexes) to expect from enumeration.
+type sampleFixture struct {
+	Alphabet string   `json:"alphabet"`
+	NumAdded int      `json:"numAdded"`
+	Words    []string `json:"words"`
+	Indexes  [][]int  `json:"indexes"`
+}
+
+// genFixture is the move-generation golden set for one sample dictionary.
+type genFixture struct {
+	Ruleset genRuleset `json:"ruleset"`
+	Cases   []genCase  `json:"cases"`
+}
+
+// genRuleset is the scoring data the TS side rebuilds so evaluate() matches the Go
+// solver: letter values, premium multipliers per square, the centre, rack size and bonus.
+type genRuleset struct {
+	Size       int     `json:"size"`
+	Cols       int     `json:"cols"`
+	Center     int     `json:"center"`
+	RackSize   int     `json:"rackSize"`
+	Bingo      int     `json:"bingo"`
+	Values     []int   `json:"values"`
+	LetterMult [][]int `json:"letterMult"`
+	WordMult   [][]int `json:"wordMult"`
+}
+
+// genTile is one placed tile (a board tile or a move placement).
+type genTile struct {
+	Row    int  `json:"row"`
+	Col    int  `json:"col"`
+	Letter int  `json:"letter"`
+	Blank  bool `json:"blank"`
+}
+
+// genRack is a rack as a multiset of letter indexes plus a blank count.
+type genRack struct {
+	Letters []int `json:"letters"`
+	Blanks  int   `json:"blanks"`
+}
+
+// genMove is one ranked generated play: its orientation, placed tiles and total score.
+type genMove struct {
+	Dir   int       `json:"dir"`
+	Tiles []genTile `json:"tiles"`
+	Score int       `json:"score"`
+}
+
+// genCase is one generation position: the tiles already on the board (empty when
+// none), the rack, the mode/rule and the ranked moves the solver returns.
+type genCase struct {
+	Name             string    `json:"name"`
+	Placed           []genTile `json:"placed"`
+	Rack             genRack   `json:"rack"`
+	Mode             int       `json:"mode"`
+	IgnoreCrossWords bool      `json:"ignoreCrossWords"`
+	Moves            []genMove `json:"moves"`
+}
+
+func main() {
+	out := flag.String("out", "ui/src/lib/dict/testdata", "output directory for fixtures")
+	dawgDir := flag.String("dawg-dir", "", "when set, emit real-dictionary move-gen golden from the .dawg files in this dir (conformance mode) instead of the committed samples")
+	flag.Parse()
+
+	if err := os.MkdirAll(*out, 0o755); err != nil {
+		log.Fatalf("movegen: mkdir %s: %v", *out, err)
+	}
+
+	if *dawgDir != "" {
+		buildReal(*dawgDir, *out)
+		return
+	}
+
+	emitRulesets()
+
+	buildSample(*out, "en", rules.English(), sampleWordsEN, []genCase{
+		emptyCase("empty-cared", englishRack("caredts", 0), scrabble.Both, false),
+		emptyCase("empty-dogs", englishRack("dogsent", 0), scrabble.Both, false),
+		emptyCase("empty-blank", englishRack("caret", 1), scrabble.Both, false),
+		emptyCase("empty-single-word", englishRack("caredts", 0), scrabble.Both, true),
+	})
+
+	buildSample(*out, "ru", rules.RussianScrabble(), sampleWordsRU, []genCase{
+		emptyCase("empty-yad", russianRack("ядрасо", 0), scrabble.Both, false),
+	})
+}
+
+// buildSample writes the dawg, the word fixture and the generation golden set for
+// one sample dictionary. Two-ply cases are appended: the solver's own top move from
+// the first non-empty result is applied, then generation runs again on the new rack.
+func buildSample(out, tag string, rs *rules.Ruleset, words []string, cases []genCase) {
+	idx := rs.Alphabet
+	b := dawg.New(idx)
+	indexes := make([][]int, 0, len(words))
+	for _, w := range words {
+		if err := b.Add(w); err != nil {
+			log.Fatalf("movegen[%s]: add %q: %v", tag, w, err)
+		}
+		enc, err := idx.Encode(w)
+		if err != nil {
+			log.Fatalf("movegen[%s]: encode %q: %v", tag, w, err)
+		}
+		ints := make([]int, len(enc))
+		for i, x := range enc {
+			ints[i] = int(x)
+		}
+		indexes = append(indexes, ints)
+	}
+	finder := b.Finish()
+
+	writeJSON(filepath.Join(out, "sample_"+tag+".words.json"), sampleFixture{
+		Alphabet: tag, NumAdded: finder.NumAdded(), Words: words, Indexes: indexes,
+	})
+	dawgPath := filepath.Join(out, "sample_"+tag+".dawg")
+	if _, err := finder.Save(dawgPath); err != nil {
+		log.Fatalf("movegen[%s]: save %s: %v", tag, dawgPath, err)
+	}
+
+	s := scrabble.NewSolver(rs, finder)
+	for i := range cases {
+		runCase(s, rs, &cases[i], nil)
+	}
+	// A two-ply position from the first standard case that produced a move.
+	if two := twoPly(s, rs, cases); two != nil {
+		cases = append(cases, *two)
+	}
+
+	writeJSON(filepath.Join(out, "sample_"+tag+".gen.json"), genFixture{
+		Ruleset: rulesetOf(rs), Cases: cases,
+	})
+	log.Printf("movegen[%s]: %d words, %d cases", tag, finder.NumAdded(), len(cases))
+}
+
+// realVariant maps a shipped dictionary file to the ruleset that scores it and the racks
+// the conformance positions use. smallRack/blankRack keep the first-move (empty board)
+// lists bounded on a dense dictionary; fullRack drives a deep 7-tile mid-game position,
+// kept small by the anchors around the already-placed word.
+type realVariant struct {
+	file, variant, smallRack, blankRack, fullRack string
+	rs                                            *rules.Ruleset
+}
+
+// buildReal emits move-generation golden from the real shipped dictionaries in dawgDir —
+// the full alphabets and deep graphs the tiny samples cannot reach — one
+// <variant>.movegen.json per variant. Like the dictgen/validategen vectors it is
+// regenerated in CI and never committed, so it pins no dictionary version into the repo.
+func buildReal(dawgDir, out string) {
+	reals := []realVariant{
+		{"en_sowpods", "scrabble_en", "aine", "ain", "aeinrst", rules.English()},
+		{"ru_scrabble", "scrabble_ru", "аеин", "аен", "аеиноср", rules.RussianScrabble()},
+		{"ru_erudit", "erudit_ru", "аеин", "аен", "аеиноср", rules.Erudit()},
+	}
+	for _, v := range reals {
+		data, err := os.ReadFile(filepath.Join(dawgDir, v.file+".dawg"))
+		if err != nil {
+			log.Fatalf("movegen[%s]: read dawg: %v", v.variant, err)
+		}
+		finder, err := dawg.Read(bytes.NewReader(data), 0)
+		if err != nil {
+			log.Fatalf("movegen[%s]: parse dawg: %v", v.variant, err)
+		}
+		s := scrabble.NewSolver(v.rs, finder)
+
+		cases := []genCase{
+			emptyCase("first-move", encRack(v.rs, v.smallRack, 0), scrabble.Both, false),
+			emptyCase("first-move-blank", encRack(v.rs, v.blankRack, 1), scrabble.Both, false),
+		}
+		for i := range cases {
+			runCase(s, v.rs, &cases[i], nil)
+		}
+		// A deep 7-tile mid-game: place the top first move, then generate again. The
+		// anchors around the placed word bound the list while still exercising a full rack,
+		// deep left/right extension and wide cross-sets over the real graph.
+		full := encRack(v.rs, v.fullRack, 0)
+		b := board.New(v.rs.Rows, v.rs.Cols)
+		if m1 := s.GenerateMovesOpts(b, toRack(v.rs.Size(), full), scrabble.Both, scrabble.PlayOptions{}); len(m1) > 0 {
+			mid := genCase{Name: "mid-game", Rack: full, Mode: int(scrabble.Both)}
+			runCase(s, v.rs, &mid, tilesOf(m1[0].Tiles))
+			cases = append(cases, mid)
+		}
+
+		writeJSON(filepath.Join(out, v.variant+".movegen.json"), genFixture{Ruleset: rulesetOf(v.rs), Cases: cases})
+		total := 0
+		for _, c := range cases {
+			total += len(c.Moves)
+		}
+		_ = finder.Close()
+		log.Printf("movegen[%s]: %d cases, %d golden moves", v.variant, len(cases), total)
+	}
+}
+
+// encRack encodes a rack given as the variant's letters (plus a blank count) into the
+// index-based genRack the fixtures carry.
+func encRack(rs *rules.Ruleset, letters string, blanks int) genRack {
+	enc, err := rs.Alphabet.Encode(letters)
+	if err != nil {
+		log.Fatalf("movegen: encode rack %q: %v", letters, err)
+	}
+	idx := make([]int, len(enc))
+	for i, b := range enc {
+		idx[i] = int(b)
+	}
+	return genRack{Letters: idx, Blanks: blanks}
+}
+
+// runCase fills a case's Moves by generating on a board holding the given placed
+// tiles (nil = empty board).
+func runCase(s *scrabble.Solver, rs *rules.Ruleset, c *genCase, placed []genTile) {
+	bd := board.New(rs.Rows, rs.Cols)
+	for _, t := range placed {
+		bd.Set(t.Row, t.Col, cellByte(t.Letter, t.Blank))
+	}
+	c.Placed = placed
+	rk := toRack(rs.Size(), c.Rack)
+	moves := s.GenerateMovesOpts(bd, rk, scrabble.Mode(c.Mode), scrabble.PlayOptions{IgnoreCrossWords: c.IgnoreCrossWords})
+	c.Moves = movesOf(moves)
+}
+
+// twoPly reaches a mid-game position by applying the top move of the first standard
+// case that generated one, then generates again with a fresh rack of the same tiles.
+func twoPly(s *scrabble.Solver, rs *rules.Ruleset, cases []genCase) *genCase {
+	for _, c := range cases {
+		if c.IgnoreCrossWords || len(c.Moves) == 0 {
+			continue
+		}
+		placed := c.Moves[0].Tiles
+		next := genCase{Name: "two-ply", Rack: c.Rack, Mode: int(scrabble.Both)}
+		runCase(s, rs, &next, placed)
+		return &next
+	}
+	return nil
+}
+
+// cellByte encodes a board cell the way internal/encoding.Cell does (bits 0-5 hold
+// letter+1, bit 7 marks a blank). Duplicated here because that package is internal
+// to the solver module and cannot be imported.
+func cellByte(letter int, blank bool) byte {
+	v := byte(letter+1) & 0x3f
+	if blank {
+		v |= 0x80
+	}
+	return v
+}
+
+func toRack(size int, r genRack) rack.Rack {
+	rk := rack.New(size)
+	for _, l := range r.Letters {
+		rk.Add(byte(l))
+	}
+	for i := 0; i < r.Blanks; i++ {
+		rk.AddBlank()
+	}
+	return rk
+}
+
+func rulesetOf(rs *rules.Ruleset) genRuleset {
+	lm := make([][]int, rs.Rows)
+	wm := make([][]int, rs.Rows)
+	for r := 0; r < rs.Rows; r++ {
+		lm[r] = make([]int, rs.Cols)
+		wm[r] = make([]int, rs.Cols)
+		for c := 0; c < rs.Cols; c++ {
+			p := rs.Premium(r, c)
+			lm[r][c] = p.LetterMult()
+			wm[r][c] = p.WordMult()
+		}
+	}
+	return genRuleset{
+		Size: rs.Size(), Cols: rs.Cols, Center: rs.Center, RackSize: rs.RackSize,
+		Bingo: rs.Bingo, Values: rs.Values, LetterMult: lm, WordMult: wm,
+	}
+}
+
+func movesOf(ms []scrabble.Move) []genMove {
+	out := make([]genMove, len(ms))
+	for i, m := range ms {
+		out[i] = genMove{Dir: int(m.Dir), Tiles: tilesOf(m.Tiles), Score: m.Score}
+	}
+	return out
+}
+
+func tilesOf(ps []scrabble.Placement) []genTile {
+	out := make([]genTile, len(ps))
+	for i, p := range ps {
+		out[i] = genTile{Row: p.Row, Col: p.Col, Letter: int(p.Letter), Blank: p.Blank}
+	}
+	return out
+}
+
+// emptyCase builds an empty-board case (Moves filled later by runCase).
+func emptyCase(name string, r genRack, mode scrabble.Mode, ignoreCross bool) genCase {
+	return genCase{Name: name, Rack: r, Mode: int(mode), IgnoreCrossWords: ignoreCross}
+}
+
+// englishRack builds a rack from lowercase a-z letters (index = letter-'a').
+func englishRack(letters string, blanks int) genRack {
+	idx := make([]int, 0, len(letters))
+	for _, ch := range letters {
+		idx = append(idx, int(ch-'a'))
+	}
+	return genRack{Letters: idx, Blanks: blanks}
+}
+
+// russianRack builds a rack from the Russian sample letters used above.
+func russianRack(letters string, blanks int) genRack {
+	m := map[rune]int{'а': 0, 'д': 4, 'о': 15, 'р': 17, 'с': 18, 'я': 32}
+	idx := make([]int, 0, len([]rune(letters)))
+	for _, ch := range letters {
+		i, ok := m[ch]
+		if !ok {
+			log.Fatalf("movegen: russianRack: no index for %q", string(ch))
+		}
+		idx = append(idx, i)
+	}
+	return genRack{Letters: idx, Blanks: blanks}
+}
+
+// emitRulesets writes the per-variant static ruleset data (tile values, bag counts, blanks,
+// bingo, rack size) the offline engine mirrors in ui/src/lib/localgame/ruleset.ts, so a TS
+// parity test can pin that hand-copied table to the Go rulesets (scrabble-solver/rules).
+func emitRulesets() {
+	type rsFix struct {
+		Size     int      `json:"size"`
+		RackSize int      `json:"rackSize"`
+		Bingo    int      `json:"bingo"`
+		Blanks   int      `json:"blanks"`
+		Values   []int    `json:"values"`
+		Counts   []int    `json:"counts"`
+		Letters  []string `json:"letters"`
+	}
+	out := map[string]rsFix{}
+	for _, v := range []struct {
+		name string
+		rs   *rules.Ruleset
+	}{
+		{"scrabble_en", rules.English()},
+		{"scrabble_ru", rules.RussianScrabble()},
+		{"erudit_ru", rules.Erudit()},
+	} {
+		letters := make([]string, v.rs.Size())
+		for i := range letters {
+			ch, err := v.rs.Alphabet.Character(byte(i))
+			if err != nil {
+				log.Fatalf("movegen: %s letter %d: %v", v.name, i, err)
+			}
+			letters[i] = strings.ToUpper(ch)
+		}
+		out[v.name] = rsFix{Size: v.rs.Size(), RackSize: v.rs.RackSize, Bingo: v.rs.Bingo, Blanks: v.rs.Blanks, Values: v.rs.Values, Counts: v.rs.Counts, Letters: letters}
+	}
+	dir := filepath.Join("ui", "src", "lib", "localgame", "testdata")
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		log.Fatalf("movegen: mkdir %s: %v", dir, err)
+	}
+	writeJSON(filepath.Join(dir, "rulesets.json"), out)
+	log.Printf("movegen: wrote %s (3 variants)", filepath.Join(dir, "rulesets.json"))
+}
+
+func writeJSON(path string, v any) {
+	data, err := json.MarshalIndent(v, "", "  ")
+	if err != nil {
+		log.Fatalf("movegen: marshal %s: %v", path, err)
+	}
+	if err := os.WriteFile(path, append(data, '\n'), 0o644); err != nil {
+		log.Fatalf("movegen: write %s: %v", path, err)
+	}
+}

backend/cmd/validategen/main.go

@@ -0,0 +1,486 @@
+// Command validategen produces golden conformance fixtures for the TypeScript
+// move validator (ui/src/lib/dict/validate.ts). For each variant it self-plays
+// greedy games with the authoritative scrabble-solver engine to build realistic
+// board positions, then records a battery of candidate plays — the engine's own
+// top move, letter-mutated variants, random scatters and (on the empty board) an
+// off-centre translation — each paired with the ground-truth result of
+// ValidatePlayOpts (legal, score, the words formed). The TS conformance test
+// replays these and must agree exactly.
+//
+// It is a development tool (not built into any service), analogous to
+// cmd/dictgen. Run it from the repository root:
+//
+//	go run ./backend/cmd/validategen -dawg-dir ../scrabble-solver/dawg -out <dir>
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"math/rand"
+	"os"
+	"path/filepath"
+
+	"gitea.iliadenisov.ru/developer/scrabble-solver/board"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/rack"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/rules"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/scrabble"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/selfplay"
+	dawg "github.com/iliadenisov/dafsa"
+)
+
+// blankTile marks a blank tile in a drawn hand (matches selfplay).
+const blankTile byte = 0xff
+
+// variantSpec pairs a variant label with its ruleset and dawg file.
+type variantSpec struct {
+	name  string
+	rules *rules.Ruleset
+	dawg  string
+}
+
+// cell is an occupied board square or a placement (alphabet-index letter).
+type cell struct {
+	R, C, Letter int
+	Blank        bool
+}
+
+// word mirrors scrabble.Word in index space.
+type word struct {
+	Row, Col, Dir int
+	Letters       []int
+	Blanks        []bool
+	Score         int
+}
+
+// fixture is one candidate play with the engine's ground-truth verdict.
+type fixture struct {
+	Board            int    `json:"board"` // index into the boards list
+	Dir              int    `json:"dir"`
+	IgnoreCrossWords bool   `json:"ignoreCrossWords"`
+	Tiles            []cell `json:"tiles"`
+	Legal            bool   `json:"legal"`
+	Score            int    `json:"score"`
+	Bonus            int    `json:"bonus"`
+	Main             *word  `json:"main,omitempty"`
+	Cross            []word `json:"cross,omitempty"`
+}
+
+// alphaEntry mirrors one row of the per-variant alphabet table the server sends the
+// client (index, concrete letter as the ruleset emits it, tile value), so the adapter
+// cross-test can drive the letter-space client path exactly as production does.
+type alphaEntry struct {
+	Index  int    `json:"index"`
+	Letter string `json:"letter"`
+	Value  int    `json:"value"`
+}
+
+// variantFile is the whole conformance payload for one variant.
+type variantFile struct {
+	Variant  string       `json:"variant"`
+	Rows     int          `json:"rows"`
+	Cols     int          `json:"cols"`
+	Center   int          `json:"center"`
+	RackSize int          `json:"rackSize"`
+	Bingo    int          `json:"bingo"`
+	Values   []int        `json:"values"`
+	Premiums []int        `json:"premiums"` // row-major rules.Premium codes
+	Alphabet []alphaEntry `json:"alphabet"`
+	Boards   [][]cell     `json:"boards"`
+	Fixtures []fixture    `json:"fixtures"`
+}
+
+func main() {
+	dawgDir := flag.String("dawg-dir", "../scrabble-solver/dawg", "directory holding the .dawg files")
+	outDir := flag.String("out", "", "output directory for the fixture files (required)")
+	games := flag.Int("games", 6, "self-play games per (variant, rule)")
+	plies := flag.Int("plies", 40, "maximum plies captured per game")
+	flag.Parse()
+	if *outDir == "" {
+		fail("-out is required")
+	}
+	if err := os.MkdirAll(*outDir, 0o755); err != nil {
+		fail("mkdir out: %v", err)
+	}
+
+	specs := []variantSpec{
+		{"scrabble_en", rules.English(), "en_sowpods.dawg"},
+		{"scrabble_ru", rules.RussianScrabble(), "ru_scrabble.dawg"},
+		{"erudit_ru", rules.Erudit(), "ru_erudit.dawg"},
+	}
+	for _, sp := range specs {
+		if err := generate(sp, *dawgDir, *outDir, *games, *plies); err != nil {
+			fail("%s: %v", sp.name, err)
+		}
+	}
+}
+
+func generate(sp variantSpec, dawgDir, outDir string, games, plies int) error {
+	data, err := os.ReadFile(filepath.Join(dawgDir, sp.dawg))
+	if err != nil {
+		return err
+	}
+	finder, err := dawg.Read(bytes.NewReader(data), 0)
+	if err != nil {
+		return fmt.Errorf("read dawg: %w", err)
+	}
+	defer finder.Close()
+
+	rs := sp.rules
+	solver := scrabble.NewSolver(rs, finder)
+
+	out := variantFile{
+		Variant: sp.name, Rows: rs.Rows, Cols: rs.Cols, Center: rs.Center,
+		RackSize: rs.RackSize, Bingo: rs.Bingo, Values: rs.Values,
+		Premiums: premiumCodes(rs), Alphabet: alphabetOf(rs),
+	}
+
+	// Capture under both the standard rule and the single-word rule, building the
+	// board with the same rule so positions are reachable under it.
+	for _, ignore := range []bool{false, true} {
+		opts := scrabble.PlayOptions{IgnoreCrossWords: ignore}
+		for g := range games {
+			seed := int64(g*1000) + boolseed(ignore) + variantSeed(sp.name)
+			playAndCapture(&out, rs, solver, opts, seed, plies)
+		}
+	}
+
+	b, err := json.Marshal(&out)
+	if err != nil {
+		return err
+	}
+	if err := os.WriteFile(filepath.Join(outDir, sp.name+".fixtures.json"), b, 0o644); err != nil {
+		return err
+	}
+	fmt.Printf("%-12s boards=%d fixtures=%d\n", sp.name, len(out.Boards), len(out.Fixtures))
+	return nil
+}
+
+// playAndCapture greedily self-plays one game, recording candidate plays against
+// each board position along the way.
+func playAndCapture(out *variantFile, rs *rules.Ruleset, solver *scrabble.Solver, opts scrabble.PlayOptions, seed int64, plies int) {
+	rng := rand.New(rand.NewSource(seed))
+	bag := selfplay.NewBag(rs, seed)
+	b := board.New(rs.Rows, rs.Cols)
+	hands := [2][]byte{bag.Draw(rs.RackSize), bag.Draw(rs.RackSize)}
+
+	passes := 0
+	for turn := range plies {
+		p := turn % 2
+		rk := rackOf(hands[p], rs.Size())
+		moves := solver.GenerateMovesOpts(b, rk, scrabble.Both, opts)
+		if len(moves) == 0 {
+			if passes++; passes >= 4 {
+				break
+			}
+			continue
+		}
+		passes = 0
+		top := moves[0]
+
+		boardIdx := len(out.Boards)
+		out.Boards = append(out.Boards, boardCells(b))
+		captureCandidates(out, rs, solver, opts, b, boardIdx, top, rng)
+
+		scrabble.Apply(b, top)
+		hands[p] = removeUsed(hands[p], top)
+		if need := rs.RackSize - len(hands[p]); need > 0 {
+			hands[p] = append(hands[p], bag.Draw(need)...)
+		}
+		if len(hands[p]) == 0 && bag.Len() == 0 {
+			break
+		}
+	}
+}
+
+// captureCandidates records the engine's top move plus derived candidates for one
+// board, each with its ValidatePlayOpts verdict.
+func captureCandidates(out *variantFile, rs *rules.Ruleset, solver *scrabble.Solver, opts scrabble.PlayOptions, b *board.Board, boardIdx int, top scrabble.Move, rng *rand.Rand) {
+	size := rs.Size()
+	record := func(tiles []scrabble.Placement) {
+		if len(tiles) == 0 {
+			return
+		}
+		out.Fixtures = append(out.Fixtures, makeFixture(solver, opts, b, boardIdx, tiles))
+	}
+
+	// The engine's own top move (legal).
+	record(top.Tiles)
+
+	// Letter-mutated variants: usually reject on the dictionary, occasionally form
+	// a different legal word.
+	for range 3 {
+		mut := clonePlacements(top.Tiles)
+		i := rng.Intn(len(mut))
+		mut[i].Letter = byte((int(mut[i].Letter) + 1 + rng.Intn(size-1)) % size)
+		record(mut)
+	}
+
+	// Random scatters: exercise geometry, dictionary and connectivity paths.
+	for range 3 {
+		record(randomScatter(b, size, 2+rng.Intn(4), rng))
+	}
+
+	// Single tiles abutting the board exercise the direction inference — a single
+	// tile is ambiguous, its orientation resolved from which axis it extends.
+	for range 3 {
+		if t, ok := randomAdjacentSingle(b, size, rng); ok {
+			record([]scrabble.Placement{t})
+		}
+	}
+
+	// On the empty board, an off-centre translation of the first move exercises the
+	// first-move centre rule.
+	if b.IsEmpty() {
+		shifted := clonePlacements(top.Tiles)
+		ok := true
+		for i := range shifted {
+			shifted[i].Row++
+			shifted[i].Col++
+			if !b.InBounds(shifted[i].Row, shifted[i].Col) {
+				ok = false
+				break
+			}
+		}
+		if ok {
+			record(shifted)
+		}
+	}
+}
+
+// makeFixture validates a candidate against board b and serializes it with its
+// ground truth. Word breakdown is recorded only for legal plays (the TS test
+// checks words only then); an illegal play records legal=false alone.
+func makeFixture(solver *scrabble.Solver, opts scrabble.PlayOptions, b *board.Board, boardIdx int, tiles []scrabble.Placement) fixture {
+	// Infer the orientation exactly as the backend evaluate does (dir-less), so the
+	// fixture matches the real eval path and pins the client's ported inference.
+	dir := playDirectionMirror(solver, b, tiles, opts)
+	fx := fixture{
+		Board:            boardIdx,
+		Dir:              int(dir),
+		IgnoreCrossWords: opts.IgnoreCrossWords,
+		Tiles:            placementCells(tiles),
+	}
+	m, err := solver.ValidatePlayOpts(b, dir, tiles, opts)
+	if err == nil {
+		fx.Legal = true
+		fx.Score = m.Score
+		fx.Bonus = m.Bonus
+		fx.Main = toWord(m.Main)
+		for _, cw := range m.Cross {
+			fx.Cross = append(fx.Cross, *toWord(cw))
+		}
+	}
+	return fx
+}
+
+func placementCells(ts []scrabble.Placement) []cell {
+	cs := make([]cell, len(ts))
+	for i, t := range ts {
+		cs[i] = cell{R: t.Row, C: t.Col, Letter: int(t.Letter), Blank: t.Blank}
+	}
+	return cs
+}
+
+func toWord(w scrabble.Word) *word {
+	letters := make([]int, len(w.Letters))
+	for i, l := range w.Letters {
+		letters[i] = int(l)
+	}
+	return &word{
+		Row: w.Row, Col: w.Col, Dir: int(w.Dir),
+		Letters: letters, Blanks: append([]bool(nil), w.Blanks...), Score: w.Score,
+	}
+}
+
+func alphabetOf(rs *rules.Ruleset) []alphaEntry {
+	n := rs.Alphabet.Size()
+	out := make([]alphaEntry, n)
+	for i := range n {
+		ch, _ := rs.Alphabet.Character(byte(i))
+		out[i] = alphaEntry{Index: i, Letter: ch, Value: rs.Values[i]}
+	}
+	return out
+}
+
+func premiumCodes(rs *rules.Ruleset) []int {
+	codes := make([]int, rs.Rows*rs.Cols)
+	for i := range codes {
+		codes[i] = int(rs.PremiumAt(i))
+	}
+	return codes
+}
+
+func boardCells(b *board.Board) []cell {
+	var cs []cell
+	for r := 0; r < b.Rows(); r++ {
+		for c := 0; c < b.Cols(); c++ {
+			if b.Filled(r, c) {
+				v := b.At(r, c)
+				cs = append(cs, cell{R: r, C: c, Letter: int(v&0x3f) - 1, Blank: v&0x80 != 0})
+			}
+		}
+	}
+	return cs
+}
+
+func clonePlacements(ts []scrabble.Placement) []scrabble.Placement {
+	return append([]scrabble.Placement(nil), ts...)
+}
+
+// randomScatter picks n distinct empty in-bounds squares with random letters.
+func randomScatter(b *board.Board, size, n int, rng *rand.Rand) []scrabble.Placement {
+	seen := map[[2]int]bool{}
+	var ts []scrabble.Placement
+	for tries := 0; tries < n*20 && len(ts) < n; tries++ {
+		r := rng.Intn(b.Rows())
+		c := rng.Intn(b.Cols())
+		if seen[[2]int{r, c}] || b.Filled(r, c) {
+			continue
+		}
+		seen[[2]int{r, c}] = true
+		ts = append(ts, scrabble.Placement{Row: r, Col: c, Letter: byte(rng.Intn(size)), Blank: rng.Intn(10) == 0})
+	}
+	return ts
+}
+
+// randomAdjacentSingle picks a random empty in-bounds square abutting at least one
+// filled square, with a random letter — a single-tile play whose orientation the
+// inference must resolve. It returns ok=false on an empty board.
+func randomAdjacentSingle(b *board.Board, size int, rng *rand.Rand) (scrabble.Placement, bool) {
+	var cands [][2]int
+	for r := 0; r < b.Rows(); r++ {
+		for c := 0; c < b.Cols(); c++ {
+			if b.Filled(r, c) {
+				continue
+			}
+			if b.Filled(r-1, c) || b.Filled(r+1, c) || b.Filled(r, c-1) || b.Filled(r, c+1) {
+				cands = append(cands, [2]int{r, c})
+			}
+		}
+	}
+	if len(cands) == 0 {
+		return scrabble.Placement{}, false
+	}
+	rc := cands[rng.Intn(len(cands))]
+	return scrabble.Placement{Row: rc[0], Col: rc[1], Letter: byte(rng.Intn(size)), Blank: rng.Intn(10) == 0}, true
+}
+
+// playDirectionMirror mirrors engine (*Game).playDirection: the geometric
+// resolution, except a single tile under the single-word rule tries both
+// orientations through the solver and keeps the higher-scoring legal one (H wins
+// ties). It reproduces the orientation the backend evaluate infers.
+func playDirectionMirror(solver *scrabble.Solver, b *board.Board, placements []scrabble.Placement, opts scrabble.PlayOptions) scrabble.Direction {
+	geo := resolveDirectionMirror(b, placements)
+	if len(placements) != 1 || !opts.IgnoreCrossWords {
+		return geo
+	}
+	best, found, bestScore := geo, false, 0
+	for _, dir := range [...]scrabble.Direction{scrabble.Horizontal, scrabble.Vertical} {
+		m, err := solver.ValidatePlayOpts(b, dir, placements, opts)
+		if err != nil {
+			continue
+		}
+		if !found || m.Score > bestScore {
+			best, found, bestScore = dir, true, m.Score
+		}
+	}
+	return best
+}
+
+// resolveDirectionMirror mirrors engine.resolveDirection.
+func resolveDirectionMirror(b *board.Board, placements []scrabble.Placement) scrabble.Direction {
+	if len(placements) >= 2 {
+		row := placements[0].Row
+		for _, p := range placements[1:] {
+			if p.Row != row {
+				return scrabble.Vertical
+			}
+		}
+		return scrabble.Horizontal
+	}
+	if len(placements) == 1 {
+		p := placements[0]
+		h := runLengthMirror(b, p.Row, p.Col, scrabble.Horizontal)
+		v := runLengthMirror(b, p.Row, p.Col, scrabble.Vertical)
+		if v >= 2 && v > h {
+			return scrabble.Vertical
+		}
+		if h >= 2 {
+			return scrabble.Horizontal
+		}
+		if v >= 2 {
+			return scrabble.Vertical
+		}
+	}
+	return scrabble.Horizontal
+}
+
+// runLengthMirror mirrors engine.runLength.
+func runLengthMirror(b *board.Board, row, col int, dir scrabble.Direction) int {
+	dr, dc := 0, 1
+	if dir == scrabble.Vertical {
+		dr, dc = 1, 0
+	}
+	n := 1
+	for r, c := row-dr, col-dc; b.Filled(r, c); r, c = r-dr, c-dc {
+		n++
+	}
+	for r, c := row+dr, col+dc; b.Filled(r, c); r, c = r+dr, c+dc {
+		n++
+	}
+	return n
+}
+
+// rackOf builds a generation rack from a hand of tiles (reimplemented from the
+// unexported selfplay helper).
+func rackOf(tiles []byte, size int) rack.Rack {
+	r := rack.New(size)
+	for _, t := range tiles {
+		if t == blankTile {
+			r.AddBlank()
+		} else {
+			r.Add(t)
+		}
+	}
+	return r
+}
+
+// removeUsed returns the hand with the tiles consumed by m removed.
+func removeUsed(tiles []byte, m scrabble.Move) []byte {
+	out := append([]byte(nil), tiles...)
+	for _, p := range m.Tiles {
+		want := p.Letter
+		if p.Blank {
+			want = blankTile
+		}
+		for i, t := range out {
+			if t == want {
+				out = append(out[:i], out[i+1:]...)
+				break
+			}
+		}
+	}
+	return out
+}
+
+func boolseed(b bool) int64 {
+	if b {
+		return 500000
+	}
+	return 0
+}
+
+func variantSeed(name string) int64 {
+	var s int64
+	for _, r := range name {
+		s = s*131 + int64(r)
+	}
+	return s
+}
+
+func fail(format string, args ...any) {
+	fmt.Fprintf(os.Stderr, "validategen: "+format+"\n", args...)
+	os.Exit(1)
+}

backend/go.mod

@@ -13,6 +13,7 @@ require (
 	github.com/pressly/goose/v3 v3.27.1
 	github.com/testcontainers/testcontainers-go v0.42.0
 	github.com/testcontainers/testcontainers-go/modules/postgres v0.42.0
+	github.com/wneessen/go-mail v0.7.3
 	go.opentelemetry.io/otel v1.43.0
 	go.opentelemetry.io/otel/exporters/stdout/stdoutmetric v1.43.0
 	go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.43.0
@@ -109,7 +110,7 @@ require (
 	golang.org/x/net v0.53.0 // indirect
 	golang.org/x/sync v0.20.0 // indirect
 	golang.org/x/sys v0.43.0 // indirect
-	golang.org/x/text v0.36.0 // indirect
+	golang.org/x/text v0.37.0 // indirect
 	google.golang.org/grpc v1.80.0
 	google.golang.org/protobuf v1.36.11 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

backend/go.sum

@@ -279,6 +279,8 @@ github.com/twitchyliquid64/golang-asm v0.15.1 h1:SU5vSMR7hnwNxj24w34ZyCi/FmDZTkS
 github.com/twitchyliquid64/golang-asm v0.15.1/go.mod h1:a1lVb/DtPvCB8fslRZhAngC2+aY1QWCk3Cedj/Gdt08=
 github.com/ugorji/go/codec v1.3.1 h1:waO7eEiFDwidsBN6agj1vJQ4AG7lh2yqXyOXqhgQuyY=
 github.com/ugorji/go/codec v1.3.1/go.mod h1:pRBVtBSKl77K30Bv8R2P+cLSGaTtex6fsA2Wjqmfxj4=
+github.com/wneessen/go-mail v0.7.3 h1:g3DravXC5SMlVdboFrQA8Jx95A8sOzoBeS5F+vzNRK0=
+github.com/wneessen/go-mail v0.7.3/go.mod h1:QGhBX0yNbc1J+Mkjcu7z2rpj4B4l+BmDY8gYznPC9sk=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 github.com/yusufpapurcu/wmi v1.2.4 h1:zFUKzehAFReQwLys1b/iSMl+JQGSCSjtVqQn9bBrPo0=
 github.com/yusufpapurcu/wmi v1.2.4/go.mod h1:SBZ9tNy3G9/m5Oi98Zks0QjeHVDvuK0qfxQmPyzfmi0=
@@ -400,6 +402,8 @@ golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 golang.org/x/text v0.36.0 h1:JfKh3XmcRPqZPKevfXVpI1wXPTqbkE5f7JA92a55Yxg=
 golang.org/x/text v0.36.0/go.mod h1:NIdBknypM8iqVmPiuco0Dh6P5Jcdk8lJL0CUebqK164=
+golang.org/x/text v0.37.0 h1:Cqjiwd9eSg8e0QAkyCaQTNHFIIzWtidPahFWR83rTrc=
+golang.org/x/text v0.37.0/go.mod h1:a5sjxXGs9hsn/AJVwuElvCAo9v8QYLzvavO5z2PiM38=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 golang.org/x/tools v0.0.0-20190425163242-31fd60d6bfdc/go.mod h1:RgjU9mgBXZiqYHBnxXauZ1Gv1EHHAz9KjViQ78xBX0Q=

backend/internal/account/account.go

@@ -22,12 +22,13 @@ import (
 	"scrabble/backend/internal/postgres/jet/backend/table"
 )
 
-// Identity kinds recognised by the backend. Email is modelled as an identity
-// alongside platform identities; its confirmed flag is driven by the email
-// confirm-code flow. Robot is a synthetic kind: each pooled
-// robot opponent is a durable account bound to one robot identity.
+// Identity kinds recognised by the backend. Telegram and VK are platform identities,
+// auto-confirmed on first contact. Email is modelled as an identity alongside them; its
+// confirmed flag is driven by the email confirm-code flow. Robot is a synthetic kind:
+// each pooled robot opponent is a durable account bound to one robot identity.
 const (
 	KindTelegram = "telegram"
+	KindVK       = "vk"
 	KindEmail    = "email"
 	KindRobot    = "robot"
 )
@@ -120,13 +121,44 @@ func (s *Store) ProvisionByIdentity(ctx context.Context, kind, externalID string
 }
 
 // ProvisionEmail returns the account owning the email identity externalID, creating
-// it (unconfirmed) on first contact with browserTZ — the client's detected "±HH:MM"
-// UTC offset — seeded into its time zone. Like ProvisionByIdentity it is race-safe
-// and leaves an existing account untouched, so a returning user's saved zone is never
-// overwritten. The email account is created here (the code-request step), not at the
-// later login, so this is where its zone is seeded.
-func (s *Store) ProvisionEmail(ctx context.Context, externalID, browserTZ string) (Account, error) {
-	return s.provision(ctx, KindEmail, externalID, provisionSeed{timeZone: seedZone(browserTZ)})
+// it on first contact with browserTZ — the client's detected "±HH:MM" UTC offset —
+// seeded into its time zone, language seeded from the client's UI language, and its
+// display name seeded from the email's local part (so it is not left nameless). Like
+// ProvisionByIdentity it is race-safe and leaves an existing account untouched, so a
+// returning user's saved zone, language and name are never overwritten. The email account is
+// created here (the code-request step), not at the later login, so this is where its
+// zone and language are seeded. It is created flagged is_guest with an unconfirmed
+// email identity: an abandoned, never-confirmed login is then reaped like any guest,
+// freeing the reserved address, and confirming the code clears the guest flag.
+func (s *Store) ProvisionEmail(ctx context.Context, externalID, browserTZ, language string) (Account, error) {
+	return s.provision(ctx, KindEmail, externalID, provisionSeed{
+		displayName:       emailDisplayName(externalID),
+		timeZone:          seedZone(browserTZ),
+		preferredLanguage: supportedLanguage(language),
+		isGuest:           true,
+	})
+}
+
+// emailDisplayName derives a display name from an email address — the local part
+// before '@', trimmed and capped to the column width — so a new email account is not
+// left nameless. It is only the first-contact seed; the user can rename it later.
+func emailDisplayName(email string) string {
+	local, _, _ := strings.Cut(email, "@")
+	local = strings.TrimSpace(local)
+	if r := []rune(local); len(r) > maxDisplayName {
+		local = strings.TrimRight(string(r[:maxDisplayName]), " ")
+	}
+	return local
+}
+
+// supportedLanguage returns code normalised to a supported UI language ("en" or
+// "ru"), or "" when it maps to neither, so a new account keeps the 'en' default. It
+// accepts region-tagged codes ("ru-RU").
+func supportedLanguage(code string) string {
+	if lang, _, _ := strings.Cut(strings.ToLower(strings.TrimSpace(code)), "-"); lang == "en" || lang == "ru" {
+		return lang
+	}
+	return ""
 }
 
 // ProvisionRobot provisions (or finds) the durable account backing a robot pool
@@ -185,6 +217,28 @@ func (s *Store) ProvisionTelegram(ctx context.Context, externalID, languageCode,
 	return acc, created, err
 }
 
+// ProvisionVK provisions (or finds) the account bound to a VK identity, reporting
+// whether this call created it (first contact). On first contact only, it seeds the new
+// account's preferred language from the VK languageCode (vk_language, when it maps to a
+// supported language) and its display name sanitized from displayName — the name read
+// client-side via VKWebAppGetUserInfo, since VK omits it from the signed launch params —
+// falling back to a generated placeholder when it yields no letters; an already-existing
+// account is returned unchanged, so a later profile edit is never overwritten.
+func (s *Store) ProvisionVK(ctx context.Context, externalID, languageCode, displayName, browserTZ string) (Account, bool, error) {
+	// Pre-check whether the identity already exists so the caller can act on first
+	// contact (mirrors ProvisionTelegram); a create race only mis-reports created for
+	// that one call.
+	_, err := s.findByIdentity(ctx, KindVK, externalID)
+	created := errors.Is(err, ErrNotFound)
+	if err != nil && !created {
+		return Account{}, false, err
+	}
+	seed := vkSeed(languageCode, displayName)
+	seed.timeZone = seedZone(browserTZ)
+	acc, err := s.provision(ctx, KindVK, externalID, seed)
+	return acc, created, err
+}
+
 // provision finds the account for (kind, externalID) or creates it with seed,
 // collapsing a concurrent-create race on the identity unique constraint into a
 // re-read of the winner's account.
@@ -216,6 +270,11 @@ type provisionSeed struct {
 	preferredLanguage string
 	displayName       string
 	timeZone          string
+	// isGuest creates the account flagged is_guest. It is set for an email-login
+	// account, which stays a guest until the address is confirmed (so an abandoned,
+	// never-confirmed login is reaped and its address freed); confirming clears the
+	// flag. Platform identities (telegram/vk) are durable from creation.
+	isGuest bool
 }
 
 // seedZone returns browserTZ when it is a well-formed zone to persist at account
@@ -258,6 +317,24 @@ func telegramSeed(languageCode, username, firstName string) provisionSeed {
 	return seed
 }
 
+// vkSeed derives the create-time seed from VK launch fields: a supported preferred
+// language from languageCode (vk_language, normally a 2-letter code) and a display name
+// from displayName (sanitized to the editable format), falling back to a generated
+// placeholder in the seeded language when the name yields no usable letters. Unlike
+// telegramSeed there is no @username fallback — VK provides only the name.
+func vkSeed(languageCode, displayName string) provisionSeed {
+	var seed provisionSeed
+	if lang, _, _ := strings.Cut(strings.ToLower(strings.TrimSpace(languageCode)), "-"); lang == "en" || lang == "ru" {
+		seed.preferredLanguage = lang
+	}
+	name := sanitizeDisplayName(displayName)
+	if name == "" {
+		name = placeholderDisplayName(seed.preferredLanguage)
+	}
+	seed.displayName = name
+	return seed
+}
+
 // GetByID loads the account identified by id, or ErrNotFound when it is absent.
 func (s *Store) GetByID(ctx context.Context, id uuid.UUID) (Account, error) {
 	stmt := postgres.SELECT(table.Accounts.AllColumns).
@@ -406,8 +483,8 @@ func (s *Store) create(ctx context.Context, kind, externalID string, seed provis
 			tz = "UTC"
 		}
 		insertAccount := table.Accounts.
-			INSERT(table.Accounts.AccountID, table.Accounts.DisplayName, table.Accounts.PreferredLanguage, table.Accounts.TimeZone).
-			VALUES(accountID, seed.displayName, lang, tz).
+			INSERT(table.Accounts.AccountID, table.Accounts.DisplayName, table.Accounts.PreferredLanguage, table.Accounts.TimeZone, table.Accounts.IsGuest).
+			VALUES(accountID, seed.displayName, lang, tz, seed.isGuest).
 			RETURNING(table.Accounts.AllColumns)
 
 		var row model.Accounts
@@ -421,7 +498,7 @@ func (s *Store) create(ctx context.Context, kind, externalID string, seed provis
 			table.Identities.Kind,
 			table.Identities.ExternalID,
 			table.Identities.Confirmed,
-		).VALUES(identityID, accountID, kind, externalID, kind == KindTelegram)
+		).VALUES(identityID, accountID, kind, externalID, kind == KindTelegram || kind == KindVK)
 		if _, err := insertIdentity.ExecContext(ctx, tx); err != nil {
 			return err
 		}

backend/internal/account/email.go

@@ -5,6 +5,7 @@ import (
 	crand "crypto/rand"
 	"crypto/sha256"
 	"database/sql"
+	"encoding/base64"
 	"encoding/hex"
 	"errors"
 	"fmt"
@@ -26,6 +27,22 @@ const (
 	emailCodeTTL = 15 * time.Minute
 	// emailCodeMaxAttempts caps wrong-code submissions before a code is dead.
 	emailCodeMaxAttempts = 5
+	// linkTokenBytes is the entropy of a confirm deeplink token: 256 bits.
+	linkTokenBytes = 32
+	// emailConfirmPath is the SPA route the one-tap confirm deeplink opens (the token
+	// is appended). The SPA is served under /app/ behind a hash router.
+	emailConfirmPath = "/app/#/confirm/"
+)
+
+// Confirmation purposes recorded on a pending confirm-code row. They select what
+// verifying the code or the deeplink token does: sign in (login), link/confirm the
+// address on the current account (link), or replace the account's confirmed email with
+// a new address (change). Account deletion adds a further purpose in a later stage.
+const (
+	purposeLogin  = "login"
+	purposeLink   = "link"
+	purposeChange = "change"
+	purposeDelete = "delete"
 )
 
 // Errors returned by the email confirm-code flow.
@@ -46,6 +63,12 @@ var (
 	ErrTooManyAttempts = errors.New("account: too many confirmation attempts")
 	// ErrCodeMismatch is returned when the submitted code does not match.
 	ErrCodeMismatch = errors.New("account: confirmation code does not match")
+	// ErrTooManyRequests is returned when confirm-code sends to an address are being
+	// requested too frequently (the resend cooldown or the rolling-hour cap).
+	ErrTooManyRequests = errors.New("account: too many code requests")
+	// ErrNoEmail is returned when an email-code step-up is requested for an account that
+	// holds no confirmed email (the caller must use the typed-phrase path instead).
+	ErrNoEmail = errors.New("account: no confirmed email")
 )
 
 // EmailService runs the email confirm-code flow: it issues a 6-digit code over a
@@ -55,14 +78,82 @@ var (
 // account is refused (ErrEmailTaken) — merging two accounts is the link/merge flow —
 // and using an email as a login reuses this mechanism.
 type EmailService struct {
-	store  *Store
-	mailer Mailer
-	now    func() time.Time
+	store   *Store
+	mailer  Mailer
+	baseURL string
+	limiter *SendLimiter
+	now     func() time.Time
 }
 
-// NewEmailService constructs an EmailService over store, sending via mailer.
-func NewEmailService(store *Store, mailer Mailer) *EmailService {
-	return &EmailService{store: store, mailer: mailer, now: func() time.Time { return time.Now().UTC() }}
+// NewEmailService constructs an EmailService over store, sending via mailer. baseURL
+// is the canonical public origin (scheme + host) used to build the one-tap confirm
+// deeplink and the email footer landing link; an empty baseURL omits the deeplink
+// (development / log mailer).
+func NewEmailService(store *Store, mailer Mailer, baseURL string) *EmailService {
+	return &EmailService{store: store, mailer: mailer, baseURL: baseURL, now: func() time.Time { return time.Now().UTC() }}
+}
+
+// SetSendLimiter installs a per-recipient send throttle. When unset (nil), sends are
+// not throttled — production wires a limiter; tests leave it off.
+func (s *EmailService) SetSendLimiter(l *SendLimiter) { s.limiter = l }
+
+// allowSend reports whether a confirm-code send to email is permitted now, recording
+// it when so. A nil limiter permits every send.
+func (s *EmailService) allowSend(email string) bool {
+	return s.limiter == nil || s.limiter.Allow(email)
+}
+
+// issueCode generates a fresh confirm-code and one-tap deeplink token for (accountID,
+// email), replaces any prior pending confirmation, and mails the branded code in
+// locale; purpose selects the email wording and what verifying does. omitLink drops the
+// one-tap deeplink from the email (account deletion, or a login requested from an installed
+// PWA). Only the SHA-256 hashes of the code and token are stored.
+func (s *EmailService) issueCode(ctx context.Context, accountID uuid.UUID, email, purpose, locale string, omitLink bool) error {
+	code, codeHash, err := generateCode()
+	if err != nil {
+		return err
+	}
+	token, tokenHash, err := generateLinkToken()
+	if err != nil {
+		return err
+	}
+	if err := s.store.replacePendingConfirmation(ctx, accountID, email, codeHash, tokenHash, purpose, s.now().Add(emailCodeTTL)); err != nil {
+		return err
+	}
+	// Omit the one-tap deeplink when asked: for a login from an installed PWA (the link would
+	// open in a separate browser whose minted session cannot reach the PWA), or for account
+	// deletion (a prefetch or stray click must not delete an account — the delete code is entered
+	// in the app only, and ConfirmByToken refuses a delete token).
+	deeplink := s.confirmURL(token, locale)
+	if purpose == purposeDelete || omitLink {
+		deeplink = ""
+	}
+	msg, err := renderConfirmationEmail(purpose, code, deeplink, s.baseURL, locale)
+	if err != nil {
+		return err
+	}
+	msg.To = email
+	return s.mailer.Send(ctx, msg)
+}
+
+// confirmURL builds the absolute one-tap confirm deeplink for token in locale, or ""
+// when no public base URL is configured. The locale rides the fragment as ?lang so the
+// confirm screen (opened in a browser with no session) renders in the email's language.
+func (s *EmailService) confirmURL(token, locale string) string {
+	if s.baseURL == "" {
+		return ""
+	}
+	return strings.TrimRight(s.baseURL, "/") + emailConfirmPath + token + "?lang=" + normalizeLocale(locale)
+}
+
+// accountLocale returns the account's preferred UI language for localising email,
+// defaulting to "en" when the account cannot be loaded.
+func (s *EmailService) accountLocale(ctx context.Context, accountID uuid.UUID) string {
+	acc, err := s.store.GetByID(ctx, accountID)
+	if err != nil {
+		return "en"
+	}
+	return acc.PreferredLanguage
 }
 
 // RequestCode issues a fresh confirm-code for email to accountID and mails it,
@@ -73,6 +164,9 @@ func (s *EmailService) RequestCode(ctx context.Context, accountID uuid.UUID, ema
 	if err != nil {
 		return err
 	}
+	if !s.allowSend(addr) {
+		return ErrTooManyRequests
+	}
 	owner, ok, err := s.store.confirmedEmailAccount(ctx, addr)
 	if err != nil {
 		return err
@@ -83,16 +177,7 @@ func (s *EmailService) RequestCode(ctx context.Context, accountID uuid.UUID, ema
 		}
 		return ErrEmailTaken
 	}
-	code, hash, err := generateCode()
-	if err != nil {
-		return err
-	}
-	if err := s.store.replacePendingConfirmation(ctx, accountID, addr, hash, s.now().Add(emailCodeTTL)); err != nil {
-		return err
-	}
-	subject := "Your Scrabble confirmation code"
-	body := fmt.Sprintf("Your confirmation code is %s. It expires in %d minutes.", code, int(emailCodeTTL/time.Minute))
-	return s.mailer.Send(ctx, addr, subject, body)
+	return s.issueCode(ctx, accountID, addr, purposeLink, s.accountLocale(ctx, accountID), false)
 }
 
 // ConfirmCode verifies code for accountID and email. On success it attaches a
@@ -123,36 +208,38 @@ func (s *EmailService) ConfirmCode(ctx context.Context, accountID uuid.UUID, ema
 	if err := s.store.confirmEmailIdentity(ctx, conf.id, accountID, addr, s.now()); err != nil {
 		return Account{}, err
 	}
+	// Binding the first confirmed email promotes a guest to a durable account, matching the
+	// link and deeplink flows (defence-in-depth: no confirmed-email path leaves is_guest set).
+	if err := s.store.ClearGuest(ctx, accountID); err != nil {
+		return Account{}, err
+	}
 	return s.store.GetByID(ctx, accountID)
 }
 
 // RequestLoginCode issues a login confirm-code to the account that owns email,
-// provisioning a fresh (unconfirmed) durable account when the email is new. It is
-// the unauthenticated email-login entry point and, unlike RequestCode,
-// does not refuse an already-confirmed email — that is the ordinary returning-user
-// login. The code is mailed to the address, so only its real owner can complete
-// the login. On first contact browserTZ (the client's detected "±HH:MM" UTC offset)
-// seeds the new account's time zone. It returns the target account id for the
-// subsequent LoginWithCode.
-func (s *EmailService) RequestLoginCode(ctx context.Context, email, browserTZ string) (uuid.UUID, error) {
+// provisioning a fresh (unconfirmed) guest account when the email is new — it becomes
+// durable once the code is confirmed. It is the unauthenticated email-login entry
+// point and, unlike RequestCode, does not refuse an already-confirmed email — that is
+// the ordinary returning-user login. The code is mailed to the address, so only its
+// real owner can complete the login. On first contact browserTZ (the client's
+// detected "±HH:MM" UTC offset) seeds the new account's time zone and language its UI
+// language. When pwa is set (the request came from an installed PWA) the login email omits the
+// one-tap confirm link — it would open in a separate browser, out of the PWA's reach — so the
+// code is entered in the same window. It returns the target account id for the subsequent
+// LoginWithCode.
+func (s *EmailService) RequestLoginCode(ctx context.Context, email, browserTZ, language string, pwa bool) (uuid.UUID, error) {
 	addr, err := normalizeEmail(email)
 	if err != nil {
 		return uuid.UUID{}, err
 	}
-	acc, err := s.store.ProvisionEmail(ctx, addr, browserTZ)
+	if !s.allowSend(addr) {
+		return uuid.UUID{}, ErrTooManyRequests
+	}
+	acc, err := s.store.ProvisionEmail(ctx, addr, browserTZ, language)
 	if err != nil {
 		return uuid.UUID{}, err
 	}
-	code, hash, err := generateCode()
-	if err != nil {
-		return uuid.UUID{}, err
-	}
-	if err := s.store.replacePendingConfirmation(ctx, acc.ID, addr, hash, s.now().Add(emailCodeTTL)); err != nil {
-		return uuid.UUID{}, err
-	}
-	subject := "Your Scrabble login code"
-	body := fmt.Sprintf("Your login code is %s. It expires in %d minutes.", code, int(emailCodeTTL/time.Minute))
-	if err := s.mailer.Send(ctx, addr, subject, body); err != nil {
+	if err := s.issueCode(ctx, acc.ID, addr, purposeLogin, language, pwa); err != nil {
 		return uuid.UUID{}, err
 	}
 	return acc.ID, nil
@@ -191,9 +278,104 @@ func (s *EmailService) LoginWithCode(ctx context.Context, email, code string) (A
 	if err := s.store.confirmEmailLogin(ctx, conf.id, acc.ID, addr, s.now()); err != nil {
 		return Account{}, err
 	}
+	if err := s.store.ClearGuest(ctx, acc.ID); err != nil {
+		return Account{}, err
+	}
 	return s.store.GetByID(ctx, acc.ID)
 }
 
+// LinkConfirmation is the outcome of confirming a one-tap deeplink token: what the
+// transport layer must finish. Purpose is the pending row's purpose. For a login,
+// Account is the account to sign in. For a link, Account is the account the email was
+// (or would be) attached to; NeedsMerge is set when another account (MergeOwner)
+// already owns the address, so the caller drives the interactive merge instead of a
+// plain link — the token is left unconsumed for that merge step.
+type LinkConfirmation struct {
+	Purpose    string
+	Account    uuid.UUID
+	NeedsMerge bool
+	MergeOwner uuid.UUID
+}
+
+// IsLogin reports whether the confirmation is a login (the caller mints a session)
+// rather than a link (attach the identity, or drive a merge).
+func (r LinkConfirmation) IsLogin() bool { return r.Purpose == purposeLogin }
+
+// ConfirmByToken verifies a one-tap deeplink token and performs its purpose. A login
+// confirms the email identity, clears the guest flag and returns the account to sign
+// in. A link attaches the confirmed email to the pending account when the address is
+// free, or reports NeedsMerge when another account already owns it (leaving the token
+// live so the caller's merge step can re-verify). It returns ErrNoPendingCode when the
+// token matches no live confirmation and ErrCodeExpired when it has lapsed. The token
+// is high-entropy, so there is no wrong-attempt counter.
+func (s *EmailService) ConfirmByToken(ctx context.Context, token string) (LinkConfirmation, error) {
+	pend, err := s.store.pendingByTokenHash(ctx, hashCode(token))
+	if err != nil {
+		return LinkConfirmation{}, err
+	}
+	if s.now().After(pend.expiresAt) {
+		return LinkConfirmation{}, ErrCodeExpired
+	}
+	switch pend.purpose {
+	case purposeLogin:
+		if err := s.store.confirmEmailLogin(ctx, pend.id, pend.accountID, pend.email, s.now()); err != nil {
+			return LinkConfirmation{}, err
+		}
+		if err := s.store.ClearGuest(ctx, pend.accountID); err != nil {
+			return LinkConfirmation{}, err
+		}
+		return LinkConfirmation{Purpose: purposeLogin, Account: pend.accountID}, nil
+	case purposeLink:
+		owner, ok, err := s.store.confirmedEmailAccount(ctx, pend.email)
+		if err != nil {
+			return LinkConfirmation{}, err
+		}
+		if ok {
+			if owner == pend.accountID {
+				if err := s.store.consumeConfirmation(ctx, pend.id, s.now()); err != nil {
+					return LinkConfirmation{}, err
+				}
+				return LinkConfirmation{Purpose: purposeLink, Account: pend.accountID}, nil
+			}
+			return LinkConfirmation{Purpose: purposeLink, Account: pend.accountID, NeedsMerge: true, MergeOwner: owner}, nil
+		}
+		if err := s.store.confirmEmailIdentity(ctx, pend.id, pend.accountID, pend.email, s.now()); err != nil {
+			return LinkConfirmation{}, err
+		}
+		// Binding the first email promotes a guest to a durable account, matching the
+		// code-based link flow (which clears the guest flag in the link service).
+		if err := s.store.ClearGuest(ctx, pend.accountID); err != nil {
+			return LinkConfirmation{}, err
+		}
+		return LinkConfirmation{Purpose: purposeLink, Account: pend.accountID}, nil
+	case purposeChange:
+		owner, ok, err := s.store.confirmedEmailAccount(ctx, pend.email)
+		if err != nil {
+			return LinkConfirmation{}, err
+		}
+		if ok && owner != pend.accountID {
+			// The new address is confirmed by a different account: refuse without
+			// disclosing it (anti-enumeration). Unlike a link, a change never merges.
+			return LinkConfirmation{}, ErrEmailTaken
+		}
+		if ok && owner == pend.accountID {
+			if err := s.store.consumeConfirmation(ctx, pend.id, s.now()); err != nil {
+				return LinkConfirmation{}, err
+			}
+			return LinkConfirmation{Purpose: purposeChange, Account: pend.accountID}, nil
+		}
+		if err := s.store.replaceEmailIdentity(ctx, pend.id, pend.accountID, pend.email, s.now()); err != nil {
+			return LinkConfirmation{}, err
+		}
+		return LinkConfirmation{Purpose: purposeChange, Account: pend.accountID}, nil
+	case purposeDelete:
+		// Deletion is confirmed in the app with the code, never via a one-tap link.
+		return LinkConfirmation{}, fmt.Errorf("account: deletion cannot be confirmed by link")
+	default:
+		return LinkConfirmation{}, fmt.Errorf("account: unsupported confirmation purpose %q", pend.purpose)
+	}
+}
+
 // emailConfirmation is a pending confirm-code row in domain form.
 type emailConfirmation struct {
 	id        uuid.UUID
@@ -222,9 +404,30 @@ func (s *Store) confirmedEmailAccount(ctx context.Context, email string) (uuid.U
 	return row.AccountID, true, nil
 }
 
+// confirmedEmailOf returns the account's confirmed email address and true, or ("", false)
+// when it holds none. It backs the deletion step-up, which mails a code to the account's
+// own address.
+func (s *Store) confirmedEmailOf(ctx context.Context, accountID uuid.UUID) (string, bool, error) {
+	stmt := postgres.SELECT(table.Identities.ExternalID).
+		FROM(table.Identities).
+		WHERE(
+			table.Identities.AccountID.EQ(postgres.UUID(accountID)).
+				AND(table.Identities.Kind.EQ(postgres.String(KindEmail))).
+				AND(table.Identities.Confirmed.EQ(postgres.Bool(true))),
+		).LIMIT(1)
+	var row model.Identities
+	if err := stmt.QueryContext(ctx, s.db, &row); err != nil {
+		if errors.Is(err, qrm.ErrNoRows) {
+			return "", false, nil
+		}
+		return "", false, fmt.Errorf("account: confirmed email of %s: %w", accountID, err)
+	}
+	return row.ExternalID, true, nil
+}
+
 // replacePendingConfirmation clears any pending code for (accountID, email) and
 // inserts a fresh one, inside one transaction.
-func (s *Store) replacePendingConfirmation(ctx context.Context, accountID uuid.UUID, email, codeHash string, expiresAt time.Time) error {
+func (s *Store) replacePendingConfirmation(ctx context.Context, accountID uuid.UUID, email, codeHash, linkTokenHash, purpose string, expiresAt time.Time) error {
 	id, err := uuid.NewV7()
 	if err != nil {
 		return fmt.Errorf("account: new confirmation id: %w", err)
@@ -241,7 +444,8 @@ func (s *Store) replacePendingConfirmation(ctx context.Context, accountID uuid.U
 		ins := table.EmailConfirmations.INSERT(
 			table.EmailConfirmations.ConfirmationID, table.EmailConfirmations.AccountID,
 			table.EmailConfirmations.Email, table.EmailConfirmations.CodeHash, table.EmailConfirmations.ExpiresAt,
-		).VALUES(id, accountID, email, codeHash, expiresAt)
+			table.EmailConfirmations.LinkTokenHash, table.EmailConfirmations.Purpose,
+		).VALUES(id, accountID, email, codeHash, expiresAt, linkTokenHash, purpose)
 		if _, err := ins.ExecContext(ctx, tx); err != nil {
 			return fmt.Errorf("insert confirmation: %w", err)
 		}
@@ -274,6 +478,54 @@ func (s *Store) latestPendingConfirmation(ctx context.Context, accountID uuid.UU
 	}, nil
 }
 
+// pendingConfirmation is a pending confirm-code row loaded by its deeplink token, in
+// domain form.
+type pendingConfirmation struct {
+	id        uuid.UUID
+	accountID uuid.UUID
+	email     string
+	purpose   string
+	expiresAt time.Time
+}
+
+// pendingByTokenHash loads the unconsumed confirmation whose deeplink token hashes to
+// tokenHash, or ErrNoPendingCode. The high-entropy token needs no attempt counter, so
+// a partial-unique index guarantees at most one match.
+func (s *Store) pendingByTokenHash(ctx context.Context, tokenHash string) (pendingConfirmation, error) {
+	stmt := postgres.SELECT(table.EmailConfirmations.AllColumns).
+		FROM(table.EmailConfirmations).
+		WHERE(
+			table.EmailConfirmations.LinkTokenHash.EQ(postgres.String(tokenHash)).
+				AND(table.EmailConfirmations.ConsumedAt.IS_NULL()),
+		).LIMIT(1)
+	var row model.EmailConfirmations
+	if err := stmt.QueryContext(ctx, s.db, &row); err != nil {
+		if errors.Is(err, qrm.ErrNoRows) {
+			return pendingConfirmation{}, ErrNoPendingCode
+		}
+		return pendingConfirmation{}, fmt.Errorf("account: load confirmation by token: %w", err)
+	}
+	return pendingConfirmation{
+		id:        row.ConfirmationID,
+		accountID: row.AccountID,
+		email:     row.Email,
+		purpose:   row.Purpose,
+		expiresAt: row.ExpiresAt,
+	}, nil
+}
+
+// consumeConfirmation marks a confirmation consumed without writing an identity, used
+// for the idempotent already-linked deeplink path.
+func (s *Store) consumeConfirmation(ctx context.Context, id uuid.UUID, now time.Time) error {
+	upd := table.EmailConfirmations.UPDATE(table.EmailConfirmations.ConsumedAt).
+		SET(postgres.TimestampzT(now)).
+		WHERE(table.EmailConfirmations.ConfirmationID.EQ(postgres.UUID(id)))
+	if _, err := upd.ExecContext(ctx, s.db); err != nil {
+		return fmt.Errorf("account: consume confirmation: %w", err)
+	}
+	return nil
+}
+
 // bumpConfirmationAttempts increments a code's wrong-attempt counter by one.
 func (s *Store) bumpConfirmationAttempts(ctx context.Context, id uuid.UUID) error {
 	stmt := table.EmailConfirmations.
@@ -320,6 +572,69 @@ func (s *Store) confirmEmailIdentity(ctx context.Context, confirmationID, accoun
 	return nil
 }
 
+// replaceEmailIdentity consumes the confirmation, deletes the account's existing email
+// identity (freeing the old address) and inserts newEmail as its confirmed email, inside
+// one transaction. It backs the change-email flow. A unique-constraint violation — the
+// new address was confirmed elsewhere in the meantime — surfaces as ErrEmailTaken. When
+// the account holds no email identity yet the delete is a no-op, so this doubles as an
+// attach.
+func (s *Store) replaceEmailIdentity(ctx context.Context, confirmationID, accountID uuid.UUID, newEmail string, now time.Time) error {
+	identityID, err := uuid.NewV7()
+	if err != nil {
+		return fmt.Errorf("account: new identity id: %w", err)
+	}
+	err = withTx(ctx, s.db, func(tx *sql.Tx) error {
+		upd := table.EmailConfirmations.
+			UPDATE(table.EmailConfirmations.ConsumedAt).
+			SET(postgres.TimestampzT(now)).
+			WHERE(table.EmailConfirmations.ConfirmationID.EQ(postgres.UUID(confirmationID)))
+		if _, err := upd.ExecContext(ctx, tx); err != nil {
+			return fmt.Errorf("consume confirmation: %w", err)
+		}
+		// Journal the outgoing email before replacing it, so the legal dossier keeps the
+		// address the account used to hold (see retention.go).
+		var old model.Identities
+		sel := postgres.SELECT(
+			table.Identities.ExternalID, table.Identities.Confirmed, table.Identities.CreatedAt,
+		).FROM(table.Identities).WHERE(
+			table.Identities.AccountID.EQ(postgres.UUID(accountID)).
+				AND(table.Identities.Kind.EQ(postgres.String(KindEmail))),
+		).LIMIT(1)
+		switch err := sel.QueryContext(ctx, tx, &old); {
+		case err == nil:
+			if err := retainIdentityTx(ctx, tx, accountID, KindEmail, old.ExternalID, old.Confirmed, old.CreatedAt, retainChange); err != nil {
+				return err
+			}
+		case errors.Is(err, qrm.ErrNoRows):
+			// No prior email (this doubles as an attach); nothing to retain.
+		default:
+			return fmt.Errorf("load outgoing email identity: %w", err)
+		}
+		del := table.Identities.DELETE().WHERE(
+			table.Identities.AccountID.EQ(postgres.UUID(accountID)).
+				AND(table.Identities.Kind.EQ(postgres.String(KindEmail))),
+		)
+		if _, err := del.ExecContext(ctx, tx); err != nil {
+			return fmt.Errorf("delete old email identity: %w", err)
+		}
+		ins := table.Identities.INSERT(
+			table.Identities.IdentityID, table.Identities.AccountID, table.Identities.Kind,
+			table.Identities.ExternalID, table.Identities.Confirmed,
+		).VALUES(identityID, accountID, KindEmail, newEmail, true)
+		if _, err := ins.ExecContext(ctx, tx); err != nil {
+			return err
+		}
+		return nil
+	})
+	if err != nil {
+		if isUniqueViolation(err) {
+			return ErrEmailTaken
+		}
+		return fmt.Errorf("account: replace email identity: %w", err)
+	}
+	return nil
+}
+
 // confirmEmailLogin consumes the login code and marks the existing email
 // identity confirmed, inside one transaction. The identity already exists (a
 // login provisioned it), so this updates rather than inserts and is idempotent
@@ -367,6 +682,18 @@ func generateCode() (code, hash string, err error) {
 	return code, hashCode(code), nil
 }
 
+// generateLinkToken returns a fresh opaque one-tap confirm deeplink token (URL-safe
+// base64, 256-bit) and its hex SHA-256 hash. Only the hash is stored; the token
+// travels only in the emailed link, mirroring the session-token model.
+func generateLinkToken() (token, hash string, err error) {
+	buf := make([]byte, linkTokenBytes)
+	if _, err := crand.Read(buf); err != nil {
+		return "", "", fmt.Errorf("account: generate link token: %w", err)
+	}
+	token = base64.RawURLEncoding.EncodeToString(buf)
+	return token, hashCode(token), nil
+}
+
 // hashCode returns the hex-encoded SHA-256 of a confirm-code.
 func hashCode(code string) string {
 	sum := sha256.Sum256([]byte(code))

backend/internal/account/emailtemplate.go

@@ -0,0 +1,239 @@
+package account
+
+import (
+	"fmt"
+	"html/template"
+	"strings"
+	tmpltext "text/template"
+	"time"
+)
+
+// emailBrandColor is the single accent used in the confirmation email — a calm
+// tile green, matching the "no riot of colours" brief.
+const emailBrandColor = "#2f7d4f"
+
+// confirmEmailView is the fully-localised data the confirmation email templates
+// render. Every string is resolved before rendering, so the templates carry no
+// localisation logic.
+type confirmEmailView struct {
+	Brand        string
+	Heading      string
+	Intro        string
+	Code         string
+	Expiry       string
+	CTALabel     string
+	DeeplinkURL  string
+	FooterIgnore string
+	LandingURL   string
+	LandingLabel string
+	Preheader    string
+	Locale       string
+	Accent       string
+}
+
+// emailCopy is the purpose- and locale-specific wording of a confirmation email.
+type emailCopy struct {
+	Subject      string
+	Preheader    string
+	Heading      string
+	Intro        string
+	CTALabel     string
+	FooterIgnore string
+}
+
+// confirmEmailCopy holds the wording per (purpose, locale). Unknown purposes fall
+// back to the neutral link wording and unknown locales fall back to English.
+var confirmEmailCopy = map[string]map[string]emailCopy{
+	purposeLogin: {
+		"en": {
+			Subject:      "Your Erudit sign-in code",
+			Preheader:    "Your sign-in code",
+			Heading:      "Sign in to Erudit",
+			Intro:        "Enter this code to sign in:",
+			CTALabel:     "Sign in with one tap",
+			FooterIgnore: "If you didn't request this email, you can safely ignore it.",
+		},
+		"ru": {
+			Subject:      "Код для входа в Эрудит",
+			Preheader:    "Ваш код для входа",
+			Heading:      "Вход в Эрудит",
+			Intro:        "Введите этот код, чтобы войти в игру:",
+			CTALabel:     "Войти одним нажатием",
+			FooterIgnore: "Если вы не запрашивали это письмо, просто проигнорируйте его.",
+		},
+	},
+	purposeLink: {
+		"en": {
+			Subject:      "Your Erudit confirmation code",
+			Preheader:    "Your confirmation code",
+			Heading:      "Confirm your e-mail",
+			Intro:        "Enter this code to confirm your address:",
+			CTALabel:     "Confirm with one tap",
+			FooterIgnore: "If you didn't request this email, you can safely ignore it.",
+		},
+		"ru": {
+			Subject:      "Код подтверждения Эрудит",
+			Preheader:    "Ваш код подтверждения",
+			Heading:      "Подтверждение e-mail",
+			Intro:        "Введите этот код, чтобы подтвердить адрес:",
+			CTALabel:     "Подтвердить одним нажатием",
+			FooterIgnore: "Если вы не запрашивали это письмо, просто проигнорируйте его.",
+		},
+	},
+	purposeChange: {
+		"en": {
+			Subject:      "Confirm your new Erudit e-mail",
+			Preheader:    "Confirm your new address",
+			Heading:      "Confirm your new e-mail",
+			Intro:        "Enter this code to switch your account to this address:",
+			CTALabel:     "Confirm with one tap",
+			FooterIgnore: "If you didn't request this change, you can safely ignore it — your address stays the same.",
+		},
+		"ru": {
+			Subject:      "Подтвердите новый e-mail в Эрудит",
+			Preheader:    "Подтвердите новый адрес",
+			Heading:      "Смена e-mail",
+			Intro:        "Введите этот код, чтобы привязать аккаунт к новому адресу:",
+			CTALabel:     "Подтвердить одним нажатием",
+			FooterIgnore: "Если вы не запрашивали смену, просто проигнорируйте письмо — адрес останется прежним.",
+		},
+	},
+	purposeDelete: {
+		"en": {
+			Subject:      "Confirm your Erudit account deletion",
+			Preheader:    "Confirm account deletion",
+			Heading:      "Delete your account",
+			Intro:        "Enter this code in the app to permanently delete your account:",
+			CTALabel:     "",
+			FooterIgnore: "If you didn't request this, ignore it — your account stays as it is.",
+		},
+		"ru": {
+			Subject:      "Подтвердите удаление аккаунта Эрудит",
+			Preheader:    "Подтверждение удаления аккаунта",
+			Heading:      "Удаление аккаунта",
+			Intro:        "Введите этот код в приложении, чтобы удалить аккаунт без восстановления:",
+			CTALabel:     "",
+			FooterIgnore: "Если вы не запрашивали удаление, проигнорируйте письмо — аккаунт останется.",
+		},
+	},
+}
+
+// emailBrand is the brand wordmark per locale.
+var emailBrand = map[string]string{"en": "Erudit", "ru": "Эрудит"}
+
+// emailExpiry formats the code-lifetime line per locale (abbreviated minutes to
+// avoid plural agreement).
+func emailExpiry(locale string, d time.Duration) string {
+	min := int(d / time.Minute)
+	if locale == "ru" {
+		return fmt.Sprintf("Код действует %d мин.", min)
+	}
+	return fmt.Sprintf("The code is valid for %d minutes.", min)
+}
+
+// normalizeLocale maps an account language to a supported email locale, defaulting
+// to English.
+func normalizeLocale(locale string) string {
+	if locale == "ru" {
+		return "ru"
+	}
+	return "en"
+}
+
+// renderConfirmationEmail builds the branded confirmation email for purpose in
+// locale: a large readable code plus a one-tap deeplink button, with an
+// ignore-notice footer and a landing link. Both a plain-text body and an HTML
+// alternative are produced. deeplinkURL is the absolute /confirm link and
+// landingURL the public landing origin.
+func renderConfirmationEmail(purpose, code, deeplinkURL, landingURL, locale string) (Message, error) {
+	loc := normalizeLocale(locale)
+	byLocale, ok := confirmEmailCopy[purpose]
+	if !ok {
+		byLocale = confirmEmailCopy[purposeLink]
+	}
+	cp := byLocale[loc]
+	view := confirmEmailView{
+		Brand:        emailBrand[loc],
+		Heading:      cp.Heading,
+		Intro:        cp.Intro,
+		Code:         code,
+		Expiry:       emailExpiry(loc, emailCodeTTL),
+		CTALabel:     cp.CTALabel,
+		DeeplinkURL:  deeplinkURL,
+		FooterIgnore: cp.FooterIgnore,
+		LandingURL:   landingURL,
+		LandingLabel: emailBrand[loc],
+		Preheader:    cp.Preheader,
+		Locale:       loc,
+		Accent:       emailBrandColor,
+	}
+	var html strings.Builder
+	if err := confirmEmailHTML.Execute(&html, view); err != nil {
+		return Message{}, fmt.Errorf("account: render confirmation email (html): %w", err)
+	}
+	var text strings.Builder
+	if err := confirmEmailText.Execute(&text, view); err != nil {
+		return Message{}, fmt.Errorf("account: render confirmation email (text): %w", err)
+	}
+	return Message{Subject: cp.Subject, Text: text.String(), HTML: html.String()}, nil
+}
+
+// confirmEmailHTML is a compact, image-free, mobile-friendly HTML email. Layout is
+// table-based for broad mail-client compatibility and all styling is inlined
+// because clients strip <style> blocks.
+var confirmEmailHTML = template.Must(template.New("confirmEmailHTML").Parse(`<!DOCTYPE html>
+<html lang="{{.Locale}}">
+<head>
+<meta charset="utf-8">
+<meta name="viewport" content="width=device-width, initial-scale=1">
+<title>{{.Brand}}</title>
+</head>
+<body style="margin:0;padding:0;background:#f4f5f7;">
+<span style="display:none;max-height:0;overflow:hidden;opacity:0;">{{.Preheader}}</span>
+<table role="presentation" width="100%" cellpadding="0" cellspacing="0" style="background:#f4f5f7;padding:24px 12px;">
+<tr><td align="center">
+<table role="presentation" width="100%" cellpadding="0" cellspacing="0" style="max-width:460px;background:#ffffff;border:1px solid #e5e7eb;border-radius:14px;overflow:hidden;font-family:-apple-system,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;">
+<tr><td style="padding:28px 32px 4px;">
+<div style="font-size:15px;font-weight:700;letter-spacing:.04em;color:{{.Accent}};">{{.Brand}}</div>
+</td></tr>
+<tr><td style="padding:8px 32px 0;">
+<h1 style="margin:0;font-size:20px;line-height:1.3;color:#111827;font-weight:600;">{{.Heading}}</h1>
+<p style="margin:12px 0 0;font-size:15px;line-height:1.5;color:#374151;">{{.Intro}}</p>
+</td></tr>
+<tr><td style="padding:18px 32px 0;">
+<div style="font-size:34px;font-weight:700;letter-spacing:8px;text-align:center;color:#111827;background:#f3f4f6;border-radius:10px;padding:18px 0;font-family:'SFMono-Regular',Consolas,Menlo,monospace;">{{.Code}}</div>
+<p style="margin:10px 0 0;font-size:13px;line-height:1.5;color:#6b7280;text-align:center;">{{.Expiry}}</p>
+</td></tr>
+{{if .DeeplinkURL}}<tr><td style="padding:22px 32px 0;" align="center">
+<a href="{{.DeeplinkURL}}" style="display:inline-block;background:{{.Accent}};color:#ffffff;text-decoration:none;font-size:15px;font-weight:600;padding:12px 26px;border-radius:9px;">{{.CTALabel}}</a>
+</td></tr>
+{{end}}<tr><td style="padding:26px 32px 28px;">
+<hr style="border:none;border-top:1px solid #eceef1;margin:0 0 16px;">
+<p style="margin:0;font-size:12px;line-height:1.6;color:#9ca3af;">{{.FooterIgnore}}</p>
+<p style="margin:10px 0 0;font-size:12px;color:#9ca3af;"><a href="{{.LandingURL}}" style="color:#6b7280;text-decoration:none;">{{.LandingLabel}}</a></p>
+</td></tr>
+</table>
+</td></tr>
+</table>
+</body>
+</html>
+`))
+
+// confirmEmailText is the plain-text alternative (and multipart fallback).
+var confirmEmailText = tmpltext.Must(tmpltext.New("confirmEmailText").Parse(`{{.Brand}}
+
+{{.Heading}}
+
+{{.Intro}}
+
+    {{.Code}}
+
+{{.Expiry}}
+
+{{if .DeeplinkURL}}{{.CTALabel}}:
+{{.DeeplinkURL}}
+
+{{end}}—
+{{.FooterIgnore}}
+{{.LandingLabel}} — {{.LandingURL}}
+`))

backend/internal/account/emailtemplate_test.go

@@ -0,0 +1,54 @@
+package account
+
+import (
+	"strings"
+	"testing"
+)
+
+// TestRenderConfirmationEmail checks that each (purpose, locale) renders a localised
+// subject, embeds the code and the one-tap deeplink in both bodies, and produces HTML.
+func TestRenderConfirmationEmail(t *testing.T) {
+	const deeplink = "https://erudit-game.ru/app/#/confirm/tok123"
+	cases := []struct {
+		name, purpose, locale, subjectSub string
+	}{
+		{"login ru", purposeLogin, "ru", "вход"},
+		{"login en", purposeLogin, "en", "sign-in"},
+		{"link ru", purposeLink, "ru", "подтвержд"},
+		{"link en", purposeLink, "en", "confirmation"},
+		{"change ru", purposeChange, "ru", "новый"},
+		{"change en", purposeChange, "en", "new"},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			msg, err := renderConfirmationEmail(c.purpose, "123456", deeplink, "https://erudit-game.ru", c.locale)
+			if err != nil {
+				t.Fatalf("render: %v", err)
+			}
+			if !strings.Contains(strings.ToLower(msg.Subject), c.subjectSub) {
+				t.Errorf("subject %q does not contain %q", msg.Subject, c.subjectSub)
+			}
+			if !strings.Contains(msg.Text, "123456") || !strings.Contains(msg.HTML, "123456") {
+				t.Error("code missing from a body")
+			}
+			if !strings.Contains(msg.Text, deeplink) || !strings.Contains(msg.HTML, "confirm/tok123") {
+				t.Error("deeplink missing from a body")
+			}
+			if !strings.Contains(msg.HTML, "<html") {
+				t.Error("HTML body is not HTML")
+			}
+		})
+	}
+}
+
+// TestRenderConfirmationEmailUnknownLocaleDefaultsEnglish falls back to English for an
+// unsupported locale rather than erroring or emitting an empty subject.
+func TestRenderConfirmationEmailUnknownLocaleDefaultsEnglish(t *testing.T) {
+	msg, err := renderConfirmationEmail(purposeLogin, "000000", "", "https://erudit-game.ru", "de")
+	if err != nil {
+		t.Fatalf("render: %v", err)
+	}
+	if !strings.Contains(strings.ToLower(msg.Subject), "sign-in") {
+		t.Errorf("unknown locale should default to English, got subject %q", msg.Subject)
+	}
+}

backend/internal/account/link.go

@@ -2,6 +2,7 @@ package account
 
 import (
 	"context"
+	"database/sql"
 	"errors"
 	"fmt"
 	"time"
@@ -16,6 +17,68 @@ import (
 // belongs to another account; the caller turns it into a merge.
 var ErrIdentityTaken = errors.New("account: identity already linked to another account")
 
+// ErrLastIdentity is returned when removing an identity would leave the account with
+// none, making it unreachable after logout. The admin email-erase refuses it.
+var ErrLastIdentity = errors.New("account: cannot remove the last identity")
+
+// RemoveIdentity deletes the account's identity of the given kind (and, for an email,
+// any pending confirmations for it), freeing it for reuse. It refuses when that is the
+// account's only identity (ErrLastIdentity) — which would leave the account
+// unreachable — and returns ErrNotFound when the account has no identity of that kind.
+// It backs the profile Unlink control and the admin "erase email" action.
+func (s *Store) RemoveIdentity(ctx context.Context, accountID uuid.UUID, kind string) error {
+	ids, err := s.Identities(ctx, accountID)
+	if err != nil {
+		return err
+	}
+	var toRetain []Identity
+	others := 0
+	for _, id := range ids {
+		if id.Kind == kind {
+			toRetain = append(toRetain, id)
+		} else {
+			others++
+		}
+	}
+	if len(toRetain) == 0 {
+		return ErrNotFound
+	}
+	if others == 0 {
+		return ErrLastIdentity
+	}
+	return withTx(ctx, s.db, func(tx *sql.Tx) error {
+		// Journal the detached credential before removing it, so the legal dossier
+		// survives while the identity frees for reuse (see retention.go).
+		for _, id := range toRetain {
+			if err := retainIdentityTx(ctx, tx, accountID, id.Kind, id.ExternalID, id.Confirmed, id.CreatedAt, retainUnlink); err != nil {
+				return err
+			}
+		}
+		delID := table.Identities.DELETE().WHERE(
+			table.Identities.AccountID.EQ(postgres.UUID(accountID)).
+				AND(table.Identities.Kind.EQ(postgres.String(kind))),
+		)
+		if _, err := delID.ExecContext(ctx, tx); err != nil {
+			return fmt.Errorf("account: delete %s identity %s: %w", kind, accountID, err)
+		}
+		if kind == KindEmail {
+			delConf := table.EmailConfirmations.DELETE().WHERE(
+				table.EmailConfirmations.AccountID.EQ(postgres.UUID(accountID)),
+			)
+			if _, err := delConf.ExecContext(ctx, tx); err != nil {
+				return fmt.Errorf("account: delete email confirmations %s: %w", accountID, err)
+			}
+		}
+		return nil
+	})
+}
+
+// RemoveEmailIdentity erases the account's email identity. It backs the admin console's
+// "erase email" action; the user-facing profile never unlinks email (it is changed).
+func (s *Store) RemoveEmailIdentity(ctx context.Context, accountID uuid.UUID) error {
+	return s.RemoveIdentity(ctx, accountID, KindEmail)
+}
+
 // RequestLinkCode issues and mails a confirm-code for email to accountID,
 // replacing any prior pending code. Unlike RequestCode it never refuses up front
 // (taken or already-confirmed): possession of the address is the authorization for
@@ -26,16 +89,10 @@ func (s *EmailService) RequestLinkCode(ctx context.Context, accountID uuid.UUID,
 	if err != nil {
 		return err
 	}
-	code, hash, err := generateCode()
-	if err != nil {
-		return err
+	if !s.allowSend(addr) {
+		return ErrTooManyRequests
 	}
-	if err := s.store.replacePendingConfirmation(ctx, accountID, addr, hash, s.now().Add(emailCodeTTL)); err != nil {
-		return err
-	}
-	subject := "Your Scrabble confirmation code"
-	body := fmt.Sprintf("Your confirmation code is %s. It expires in %d minutes.", code, int(emailCodeTTL/time.Minute))
-	return s.mailer.Send(ctx, addr, subject, body)
+	return s.issueCode(ctx, accountID, addr, purposeLink, s.accountLocale(ctx, accountID), false)
 }
 
 // ConfirmLink verifies code for (accountID, email) and reports the address's
@@ -70,6 +127,100 @@ func (s *EmailService) ConfirmLink(ctx context.Context, accountID uuid.UUID, ema
 	return accountID, true, nil
 }
 
+// RequestChangeCode issues and mails a confirm-code to newEmail for an authenticated
+// email change on accountID, replacing any prior pending code. Like RequestLinkCode it
+// never refuses up front on "taken" (anti-enumeration): possession of newEmail is the
+// authorization, and a conflict with another account is revealed only at confirm — as a
+// non-disclosing refusal, never a merge.
+func (s *EmailService) RequestChangeCode(ctx context.Context, accountID uuid.UUID, newEmail string) error {
+	addr, err := normalizeEmail(newEmail)
+	if err != nil {
+		return err
+	}
+	if !s.allowSend(addr) {
+		return ErrTooManyRequests
+	}
+	return s.issueCode(ctx, accountID, addr, purposeChange, s.accountLocale(ctx, accountID), false)
+}
+
+// ConfirmChange verifies code for (accountID, newEmail) and atomically replaces the
+// account's confirmed email with newEmail, freeing the old address. When newEmail is
+// already confirmed by another account it refuses with ErrEmailTaken (surfaced to the
+// user as a non-disclosing "check the address or contact support"), never merging; when
+// the account already owns newEmail it is an idempotent no-op. It returns the usual
+// confirm-code errors (ErrNoPendingCode, ErrCodeExpired, ErrTooManyAttempts,
+// ErrCodeMismatch) and the updated account on success.
+func (s *EmailService) ConfirmChange(ctx context.Context, accountID uuid.UUID, newEmail, code string) (Account, error) {
+	addr, err := normalizeEmail(newEmail)
+	if err != nil {
+		return Account{}, err
+	}
+	conf, err := s.verifyPendingCode(ctx, accountID, addr, code)
+	if err != nil {
+		return Account{}, err
+	}
+	owner, ok, err := s.store.confirmedEmailAccount(ctx, addr)
+	if err != nil {
+		return Account{}, err
+	}
+	if ok && owner != accountID {
+		return Account{}, ErrEmailTaken
+	}
+	if ok && owner == accountID {
+		if err := s.store.consumeConfirmation(ctx, conf.id, s.now()); err != nil {
+			return Account{}, err
+		}
+		return s.store.GetByID(ctx, accountID)
+	}
+	if err := s.store.replaceEmailIdentity(ctx, conf.id, accountID, addr, s.now()); err != nil {
+		return Account{}, err
+	}
+	return s.store.GetByID(ctx, accountID)
+}
+
+// HasEmail reports whether accountID owns a confirmed email. The account-deletion step-up
+// mails a confirm-code when it does, and falls back to a typed phrase otherwise.
+func (s *EmailService) HasEmail(ctx context.Context, accountID uuid.UUID) (bool, error) {
+	_, ok, err := s.store.confirmedEmailOf(ctx, accountID)
+	return ok, err
+}
+
+// RequestDeleteCode mails an account-deletion confirm-code to the account's own confirmed
+// email (no deeplink — deletion is confirmed in the app). It returns ErrNoEmail when the
+// account holds no email, ErrTooManyRequests when throttled.
+func (s *EmailService) RequestDeleteCode(ctx context.Context, accountID uuid.UUID) error {
+	addr, ok, err := s.store.confirmedEmailOf(ctx, accountID)
+	if err != nil {
+		return err
+	}
+	if !ok {
+		return ErrNoEmail
+	}
+	if !s.allowSend(addr) {
+		return ErrTooManyRequests
+	}
+	return s.issueCode(ctx, accountID, addr, purposeDelete, s.accountLocale(ctx, accountID), false)
+}
+
+// VerifyDeleteCode verifies the account-deletion code against the account's own email and
+// consumes it on success. It returns ErrNoEmail (no email), the usual confirm-code errors
+// (ErrNoPendingCode, ErrCodeExpired, ErrTooManyAttempts, ErrCodeMismatch), or nil when the
+// code is valid — the caller then performs the deletion.
+func (s *EmailService) VerifyDeleteCode(ctx context.Context, accountID uuid.UUID, code string) error {
+	addr, ok, err := s.store.confirmedEmailOf(ctx, accountID)
+	if err != nil {
+		return err
+	}
+	if !ok {
+		return ErrNoEmail
+	}
+	conf, err := s.verifyPendingCode(ctx, accountID, addr, code)
+	if err != nil {
+		return err
+	}
+	return s.store.consumeConfirmation(ctx, conf.id, s.now())
+}
+
 // verifyPendingCode loads and checks the pending confirm-code for (accountID,
 // addr), counting a wrong attempt. It returns the confirmation on success.
 func (s *EmailService) verifyPendingCode(ctx context.Context, accountID uuid.UUID, addr, code string) (emailConfirmation, error) {

backend/internal/account/mailer.go

@@ -3,33 +3,99 @@ package account
 import (
 	"context"
 	"fmt"
-	"net"
-	"net/smtp"
+	"strconv"
+	"strings"
+	"time"
 
+	"github.com/wneessen/go-mail"
 	"go.uber.org/zap"
 )
 
+// Message is a transactional email to send through a Mailer. Text is the
+// required plain-text body and doubles as the multipart/alternative fallback;
+// HTML, when non-empty, is the preferred body a capable client renders instead.
+type Message struct {
+	// To is the recipient address, or several comma-separated (all get the one message).
+	To string
+	// From, when non-empty, overrides the configured sender for this message — the admin
+	// alert path uses a distinct From from the user-facing confirm-code sender.
+	From    string
+	Subject string
+	Text    string
+	HTML    string
+}
+
 // Mailer delivers a transactional email. It is the seam behind which the email
 // confirm-code flow sends codes, so the relay is swappable and unit tests use a
-// fixture (see docs/TESTING.md: no real network in tests). The context is offered
-// for cancellation; the standard-library SMTP implementation sends synchronously
-// and ignores it.
+// fixture (see docs/TESTING.md: no real network in tests). The context bounds the
+// delivery and is honoured by the SMTP implementation.
 type Mailer interface {
-	Send(ctx context.Context, to, subject, body string) error
+	Send(ctx context.Context, msg Message) error
+}
+
+// splitAddrs splits a comma-separated recipient list into trimmed, non-empty addresses.
+func splitAddrs(list string) []string {
+	parts := strings.Split(list, ",")
+	out := make([]string, 0, len(parts))
+	for _, p := range parts {
+		if a := strings.TrimSpace(p); a != "" {
+			out = append(out, a)
+		}
+	}
+	return out
 }
 
 // SMTPConfig configures the SMTP relay. An empty Host selects the LogMailer
 // instead, so a deployment without a relay still runs (the code lands in the log).
+// TLS is always used and no client certificate is required — only the server
+// certificate is validated against the system roots.
 type SMTPConfig struct {
 	Host     string
 	Port     string
 	Username string
 	Password string
 	From     string
+	// TLS selects the transport security: "ssl" for implicit TLS from connect, or
+	// "starttls" to upgrade a plaintext connection. Empty derives the mode from the
+	// port (implicit TLS on 465, STARTTLS otherwise); set it explicitly for a relay on
+	// a non-standard port (e.g. Selectel's 1127 = SSL, 1126 = STARTTLS).
+	TLS string
+	// AdminFrom / AdminTo drive the operator alert emails (new feedback / word complaints),
+	// distinct from the user-facing confirm-code sender. AdminTo may be several
+	// comma-separated addresses. Both empty disables the alert worker.
+	AdminFrom string
+	AdminTo   string
 }
 
-// SMTPMailer sends mail through an SMTP relay using the standard library. When a
-// username is set it authenticates with PLAIN; otherwise it relays unauthenticated.
+const (
+	// SMTP transport-security modes for SMTPConfig.TLS.
+	smtpTLSImplicit = "ssl"
+	smtpTLSSTARTTLS = "starttls"
+	// smtpDialTimeout bounds a single relay connect-and-send. The confirm-code send
+	// is synchronous on the request path, so an unreachable relay must fail fast
+	// rather than hold the request open.
+	smtpDialTimeout = 15 * time.Second
+)
+
+// tlsMode resolves the transport-security mode for the relay: the explicitly
+// configured SMTPConfig.TLS, or — when unset — implicit TLS on the conventional SSL
+// port 465 and STARTTLS on any other port.
+func (cfg SMTPConfig) tlsMode(port int) string {
+	switch strings.ToLower(strings.TrimSpace(cfg.TLS)) {
+	case smtpTLSImplicit, "tls":
+		return smtpTLSImplicit
+	case smtpTLSSTARTTLS:
+		return smtpTLSSTARTTLS
+	}
+	if port == 465 {
+		return smtpTLSImplicit
+	}
+	return smtpTLSSTARTTLS
+}
+
+// SMTPMailer sends mail through an SMTP relay using go-mail. When a username is
+// set it authenticates, auto-discovering the strongest mechanism the relay
+// advertises; otherwise it relays unauthenticated.
 type SMTPMailer struct {
 	cfg SMTPConfig
 }
@@ -39,29 +105,55 @@ func NewSMTPMailer(cfg SMTPConfig) SMTPMailer {
 	return SMTPMailer{cfg: cfg}
 }
 
-// Send delivers a plain-text UTF-8 message to to via the configured relay.
-func (m SMTPMailer) Send(_ context.Context, to, subject, body string) error {
-	addr := net.JoinHostPort(m.cfg.Host, m.cfg.Port)
-	var auth smtp.Auth
-	if m.cfg.Username != "" {
-		auth = smtp.PlainAuth("", m.cfg.Username, m.cfg.Password, m.cfg.Host)
+// Send delivers a UTF-8 message to msg.To via the configured relay. When msg.HTML
+// is set the message is multipart/alternative (plain text plus HTML); otherwise
+// it is plain text only.
+func (m SMTPMailer) Send(ctx context.Context, msg Message) error {
+	port, err := strconv.Atoi(m.cfg.Port)
+	if err != nil {
+		return fmt.Errorf("account: invalid SMTP port %q: %w", m.cfg.Port, err)
 	}
-	if err := smtp.SendMail(addr, auth, m.cfg.From, []string{to}, message(m.cfg.From, to, subject, body)); err != nil {
-		return fmt.Errorf("account: send mail to %s: %w", to, err)
+	opts := []mail.Option{mail.WithPort(port), mail.WithTimeout(smtpDialTimeout)}
+	if m.cfg.tlsMode(port) == smtpTLSImplicit {
+		opts = append(opts, mail.WithSSL())
+	} else {
+		opts = append(opts, mail.WithTLSPortPolicy(mail.TLSMandatory))
+	}
+	if m.cfg.Username != "" {
+		opts = append(opts,
+			mail.WithSMTPAuth(mail.SMTPAuthAutoDiscover),
+			mail.WithUsername(m.cfg.Username),
+			mail.WithPassword(m.cfg.Password),
+		)
+	}
+	client, err := mail.NewClient(m.cfg.Host, opts...)
+	if err != nil {
+		return fmt.Errorf("account: build mail client: %w", err)
+	}
+	out := mail.NewMsg()
+	from := m.cfg.From
+	if msg.From != "" {
+		from = msg.From
+	}
+	if err := out.From(from); err != nil {
+		return fmt.Errorf("account: set From %q: %w", from, err)
+	}
+	// To may carry several comma-separated recipients; go-mail wants them as separate
+	// arguments (a single joined string parses as one malformed address).
+	if err := out.To(splitAddrs(msg.To)...); err != nil {
+		return fmt.Errorf("account: set To %q: %w", msg.To, err)
+	}
+	out.Subject(msg.Subject)
+	out.SetBodyString(mail.TypeTextPlain, msg.Text)
+	if msg.HTML != "" {
+		out.AddAlternativeString(mail.TypeTextHTML, msg.HTML)
+	}
+	if err := client.DialAndSendWithContext(ctx, out); err != nil {
+		return fmt.Errorf("account: send mail to %s: %w", msg.To, err)
 	}
 	return nil
 }
 
-// message renders a minimal RFC 5322 plain-text email.
-func message(from, to, subject, body string) []byte {
-	return []byte("From: " + from + "\r\n" +
-		"To: " + to + "\r\n" +
-		"Subject: " + subject + "\r\n" +
-		"MIME-Version: 1.0\r\n" +
-		"Content-Type: text/plain; charset=UTF-8\r\n" +
-		"\r\n" + body + "\r\n")
-}
-
 // LogMailer logs the message instead of sending it. It is the default when no
 // SMTP relay is configured and is intended for development only: it logs the body,
 // which carries the confirm-code, so it must not be used in production.
@@ -74,11 +166,12 @@ func NewLogMailer(log *zap.Logger) LogMailer {
 	return LogMailer{log: log}
 }
 
-// Send logs the message at info level and reports success.
-func (m LogMailer) Send(_ context.Context, to, subject, body string) error {
+// Send logs the message at info level and reports success. It logs the plain-text
+// body only (which carries the confirm-code); the HTML alternative is omitted.
+func (m LogMailer) Send(_ context.Context, msg Message) error {
 	if m.log != nil {
 		m.log.Info("email not sent (log mailer)",
-			zap.String("to", to), zap.String("subject", subject), zap.String("body", body))
+			zap.String("to", msg.To), zap.String("subject", msg.Subject), zap.String("body", msg.Text))
 	}
 	return nil
 }

backend/internal/account/mailer_test.go

@@ -0,0 +1,51 @@
+package account
+
+import (
+	"slices"
+	"testing"
+)
+
+// TestSplitAddrs covers the comma-separated recipient parsing used for the admin alert
+// To (several operator mailboxes in one message), including trimming and empty entries.
+func TestSplitAddrs(t *testing.T) {
+	cases := []struct {
+		in   string
+		want []string
+	}{
+		{"a@x.ru", []string{"a@x.ru"}},
+		{"a@x.ru, b@y.ru", []string{"a@x.ru", "b@y.ru"}},
+		{" a@x.ru ,, b@y.ru ,", []string{"a@x.ru", "b@y.ru"}},
+		{"", nil},
+	}
+	for _, c := range cases {
+		if got := splitAddrs(c.in); !slices.Equal(got, c.want) {
+			t.Errorf("splitAddrs(%q) = %v, want %v", c.in, got, c.want)
+		}
+	}
+}
+
+// TestSMTPTLSMode covers the explicit TLS mode and the port-based fallback, including
+// the non-standard Selectel ports (1127 = SSL, 1126 = STARTTLS) that the 465 heuristic
+// alone cannot classify.
+func TestSMTPTLSMode(t *testing.T) {
+	cases := []struct {
+		name string
+		tls  string
+		port int
+		want string
+	}{
+		{"explicit ssl on a custom port (Selectel 1127)", "ssl", 1127, smtpTLSImplicit},
+		{"explicit starttls on a custom port (Selectel 1126)", "starttls", 1126, smtpTLSSTARTTLS},
+		{"tls is an alias for ssl", "TLS", 2525, smtpTLSImplicit},
+		{"empty derives implicit TLS on 465", "", 465, smtpTLSImplicit},
+		{"empty derives STARTTLS on 587", "", 587, smtpTLSSTARTTLS},
+		{"an unknown value falls back to the port heuristic", "bogus", 465, smtpTLSImplicit},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			if got := (SMTPConfig{TLS: c.tls}).tlsMode(c.port); got != c.want {
+				t.Errorf("tlsMode(TLS=%q, port=%d) = %q, want %q", c.tls, c.port, got, c.want)
+			}
+		})
+	}
+}

backend/internal/account/profile.go

@@ -101,6 +101,66 @@ func validateVariantPreferences(prefs []string) ([]string, error) {
 	return out, nil
 }
 
+// variantSeedPrefix marks a Telegram start-param payload that seeds a brand-new
+// account's variant preferences (e.g. "verudit_ru-scrabble_en"): the prefix, then the
+// canonical variant labels joined by "-". It is deliberately distinct from the routing
+// deep links (g/i/f; see platform/telegram .../deeplink) so the client's start-param
+// router falls through to the lobby for it.
+const variantSeedPrefix = "v"
+
+// SeedVariantsFromStartParam decodes a promo deep-link start-param into the variant
+// preference set to seed onto a brand-new account: the variantSeedPrefix followed by
+// the canonical variant labels joined by "-" (e.g. "verudit_ru-scrabble_en"). It
+// returns nil for any payload that is not a variant-seed link or that fails validation
+// against the known variants, so a malformed, empty or unrelated start-param simply
+// leaves the account on its default preferences rather than failing the login.
+func SeedVariantsFromStartParam(startParam string) []string {
+	if !strings.HasPrefix(startParam, variantSeedPrefix) {
+		return nil
+	}
+	body := strings.TrimPrefix(startParam, variantSeedPrefix)
+	if body == "" {
+		return nil
+	}
+	prefs, err := validateVariantPreferences(strings.Split(body, "-"))
+	if err != nil {
+		return nil
+	}
+	return prefs
+}
+
+// SetVariantPreferences overwrites only the variant-preference set of the account,
+// cleaning it to a deduplicated, canonically ordered subset of the known variants
+// (rejecting an empty or unknown set with ErrInvalidProfile) and bumping updated_at; it
+// reports ErrNotFound when no account matches id. It is the narrow counterpart to
+// UpdateProfile used to seed a promo-onboarded account's variants at first contact
+// without disturbing its other profile fields.
+func (s *Store) SetVariantPreferences(ctx context.Context, id uuid.UUID, prefs []string) (Account, error) {
+	clean, err := validateVariantPreferences(prefs)
+	if err != nil {
+		return Account{}, err
+	}
+	stmt := table.Accounts.UPDATE(
+		table.Accounts.VariantPreferences, table.Accounts.UpdatedAt,
+	).SET(
+		// clean is validated against the closed knownVariants set; bind as a text[]
+		// parameter (lib/pq encodes the array, the cast pins the column type), mirroring
+		// UpdateProfile.
+		postgres.Raw("#variant_prefs::text[]", map[string]interface{}{"#variant_prefs": pq.StringArray(clean)}),
+		postgres.TimestampzT(time.Now().UTC()),
+	).WHERE(table.Accounts.AccountID.EQ(postgres.UUID(id))).
+		RETURNING(table.Accounts.AllColumns)
+
+	var row model.Accounts
+	if err := stmt.QueryContext(ctx, s.db, &row); err != nil {
+		if errors.Is(err, qrm.ErrNoRows) {
+			return Account{}, ErrNotFound
+		}
+		return Account{}, fmt.Errorf("account: set variant preferences %s: %w", id, err)
+	}
+	return modelToAccount(row), nil
+}
+
 // UpdateProfile validates and overwrites the editable fields of the account, then
 // returns the stored row. It reports ErrInvalidProfile for a bad language,
 // timezone or display name and ErrNotFound when no account matches id.

backend/internal/account/provision_test.go

@@ -75,3 +75,55 @@ func TestTelegramSeedTruncatesLongName(t *testing.T) {
 		t.Errorf("display name rune count = %d, want %d", n, maxDisplayName)
 	}
 }
+
+// TestVKSeed covers the pure mapping from VK launch fields to the create-time account
+// seed: supported-language detection from vk_language (bare and region-tagged) and the
+// display name sanitized from the client-supplied name. Unlike Telegram there is no
+// @username fallback — VK provides only the name.
+func TestVKSeed(t *testing.T) {
+	cases := map[string]struct {
+		languageCode, displayName string
+		wantLang, wantName        string
+	}{
+		"ru bare":          {"ru", "Иван", "ru", "Иван"},
+		"en region-tagged": {"en-US", "John", "en", "John"},
+		"full name kept":   {"ru", "Иван Петров", "ru", "Иван Петров"},
+		"unknown language": {"uk", "Тарас", "", "Тарас"},
+		"empty language":   {"", "Neo", "", "Neo"},
+		"trimmed":          {" RU ", "  Anna  ", "ru", "Anna"},
+		"emoji stripped":   {"en", "🎮Kaya🎮", "en", "Kaya"},
+	}
+	for name, tc := range cases {
+		t.Run(name, func(t *testing.T) {
+			got := vkSeed(tc.languageCode, tc.displayName)
+			if got.preferredLanguage != tc.wantLang {
+				t.Errorf("preferredLanguage = %q, want %q", got.preferredLanguage, tc.wantLang)
+			}
+			if got.displayName != tc.wantName {
+				t.Errorf("displayName = %q, want %q", got.displayName, tc.wantName)
+			}
+		})
+	}
+}
+
+// TestVKSeedPlaceholder checks a VK name with no usable letters falls back to a
+// generated placeholder in the seeded language ("Player-NNNNN" / "Игрок-NNNNN").
+func TestVKSeedPlaceholder(t *testing.T) {
+	cases := map[string]struct {
+		languageCode, displayName string
+		wantRe                    string
+	}{
+		"en empty":     {"en", "", `^Player-\d{5}$`},
+		"ru empty":     {"ru", "", `^Игрок-\d{5}$`},
+		"default en":   {"uk", "", `^Player-\d{5}$`},
+		"name garbage": {"ru", "123!@#", `^Игрок-\d{5}$`},
+	}
+	for name, tc := range cases {
+		t.Run(name, func(t *testing.T) {
+			got := vkSeed(tc.languageCode, tc.displayName).displayName
+			if !regexp.MustCompile(tc.wantRe).MatchString(got) {
+				t.Errorf("displayName = %q, want match %s", got, tc.wantRe)
+			}
+		})
+	}
+}

backend/internal/account/ratelimit.go

@@ -0,0 +1,66 @@
+package account
+
+import (
+	"sync"
+	"time"
+)
+
+// SendLimiter throttles confirm-code sends per recipient address: it enforces a
+// minimum cooldown between two sends and a cap over a rolling hour. It guards against
+// email bombing and protects the relay's own quota. State is in-memory (per process,
+// reset on restart) and keyed by the normalised recipient address, which is adequate
+// for the single-instance backend. Safe for concurrent use.
+type SendLimiter struct {
+	mu       sync.Mutex
+	cooldown time.Duration
+	perHour  int
+	now      func() time.Time
+	sends    map[string][]time.Time
+}
+
+// NewSendLimiter returns a SendLimiter allowing at most one send per cooldown and at
+// most perHour sends over any rolling hour, to the same recipient.
+func NewSendLimiter(cooldown time.Duration, perHour int) *SendLimiter {
+	return &SendLimiter{
+		cooldown: cooldown,
+		perHour:  perHour,
+		now:      func() time.Time { return time.Now() },
+		sends:    make(map[string][]time.Time),
+	}
+}
+
+// Allow reports whether a send to key is permitted now, recording the send when it is.
+// It is denied when the last send was within the cooldown or the rolling-hour cap is
+// already reached.
+func (l *SendLimiter) Allow(key string) bool {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	now := l.now()
+	cutoff := now.Add(-time.Hour)
+	kept := l.sends[key][:0]
+	for _, t := range l.sends[key] {
+		if t.After(cutoff) {
+			kept = append(kept, t)
+		}
+	}
+	if n := len(kept); n > 0 && now.Sub(kept[n-1]) < l.cooldown {
+		l.set(key, kept)
+		return false
+	}
+	if len(kept) >= l.perHour {
+		l.set(key, kept)
+		return false
+	}
+	l.set(key, append(kept, now))
+	return true
+}
+
+// set stores the retained send times for key, dropping the entry entirely once empty
+// so the map stays bounded to recipients active within the last hour.
+func (l *SendLimiter) set(key string, times []time.Time) {
+	if len(times) == 0 {
+		delete(l.sends, key)
+		return
+	}
+	l.sends[key] = times
+}

backend/internal/account/ratelimit_test.go

@@ -0,0 +1,43 @@
+package account
+
+import (
+	"testing"
+	"time"
+)
+
+// TestSendLimiter checks the per-recipient cooldown and the rolling-hour cap, and
+// that recipients are throttled independently.
+func TestSendLimiter(t *testing.T) {
+	base := time.Now()
+	now := base
+	l := NewSendLimiter(time.Minute, 3)
+	l.now = func() time.Time { return now }
+
+	if !l.Allow("a") {
+		t.Fatal("send 1 should be allowed")
+	}
+	if l.Allow("a") {
+		t.Fatal("immediate resend must be blocked by the cooldown")
+	}
+	if !l.Allow("b") {
+		t.Fatal("a different recipient is independent")
+	}
+
+	now = base.Add(time.Minute)
+	if !l.Allow("a") {
+		t.Fatal("send 2 after the cooldown should be allowed")
+	}
+	now = base.Add(2 * time.Minute)
+	if !l.Allow("a") {
+		t.Fatal("send 3 should be allowed")
+	}
+	now = base.Add(3 * time.Minute)
+	if l.Allow("a") {
+		t.Fatal("send 4 within the hour must be blocked by the cap")
+	}
+
+	now = base.Add(time.Hour + time.Minute)
+	if !l.Allow("a") {
+		t.Fatal("after the rolling hour the cap resets")
+	}
+}

backend/internal/account/retention.go

@@ -0,0 +1,224 @@
+package account
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/go-jet/jet/v2/postgres"
+	"github.com/go-jet/jet/v2/qrm"
+	"github.com/google/uuid"
+	"go.uber.org/zap"
+
+	"scrabble/backend/internal/postgres/jet/backend/model"
+	"scrabble/backend/internal/postgres/jet/backend/table"
+)
+
+// RetentionTTL bounds how long the account-deletion legal dossier is kept before the
+// reaper purges it: two years from the detach/deletion event (owner policy, 2026-07-03).
+const RetentionTTL = 2 * 365 * 24 * time.Hour
+
+// Reasons recorded on a retained_identities row: what detached the credential from its
+// account (unlink / email change / account deletion here; an account merge that drops a
+// same-kind colliding identity writes reason "merge" from the accountmerge package). The
+// row is written just before the live identities row is removed, preserving the legal
+// dossier (which email/vk/tg was linked, and when) even as the identity frees for reuse.
+// See docs/ARCHITECTURE.md §9.1.
+const (
+	retainUnlink = "unlink"
+	retainChange = "change"
+	retainDelete = "delete"
+)
+
+// retainIdentityTx appends a retention-journal row for one identity being detached, inside
+// tx. linkedAt is the identity's original creation time; detached_at defaults to now(). It
+// must run in the same transaction as the identity removal, so the dossier and the live
+// state can never diverge.
+func retainIdentityTx(ctx context.Context, tx *sql.Tx, accountID uuid.UUID, kind, externalID string, confirmed bool, linkedAt time.Time, reason string) error {
+	id, err := uuid.NewV7()
+	if err != nil {
+		return fmt.Errorf("account: new retained id: %w", err)
+	}
+	ins := table.RetainedIdentities.INSERT(
+		table.RetainedIdentities.RetainedID, table.RetainedIdentities.AccountID,
+		table.RetainedIdentities.Kind, table.RetainedIdentities.ExternalID,
+		table.RetainedIdentities.Confirmed, table.RetainedIdentities.LinkedAt,
+		table.RetainedIdentities.Reason,
+	).VALUES(id, accountID, kind, externalID, confirmed, linkedAt, reason)
+	if _, err := ins.ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("account: retain identity (%s, %s): %w", kind, externalID, err)
+	}
+	return nil
+}
+
+// StampLastLogin records the account's last cold-load time and client IP, but only when
+// the stored value is missing or older than an hour — so it costs at most one write per
+// account per hour (its caller, the profile fetch, runs once per cold app-load). It is a
+// best-effort audit signal that feeds the account-deletion dossier.
+func (s *Store) StampLastLogin(ctx context.Context, accountID uuid.UUID, ip string) error {
+	now := time.Now().UTC()
+	upd := table.Accounts.UPDATE(table.Accounts.LastLoginAt, table.Accounts.LastLoginIP).
+		SET(postgres.TimestampzT(now), postgres.String(ip)).
+		WHERE(
+			table.Accounts.AccountID.EQ(postgres.UUID(accountID)).
+				AND(
+					table.Accounts.LastLoginAt.IS_NULL().
+						OR(table.Accounts.LastLoginAt.LT(postgres.TimestampzT(now.Add(-time.Hour)))),
+				),
+		)
+	if _, err := upd.ExecContext(ctx, s.db); err != nil {
+		return fmt.Errorf("account: stamp last login %s: %w", accountID, err)
+	}
+	return nil
+}
+
+// ReapExpiredRetention purges retention data whose event is older than cutoff: every
+// retained_identities row by its detached_at (covering unlink/change on live accounts as
+// well as deleted ones), plus — for accounts tombstoned before cutoff — the retained
+// feedback thread and the dossier PII (deleted_display_name, last_login_ip). Chat is kept
+// (a shared game artifact), and the tombstone account row itself stays (its no-cascade
+// foreign keys). It returns how many journal rows and feedback messages were removed.
+func (s *Store) ReapExpiredRetention(ctx context.Context, cutoff time.Time) (identities, feedback int64, err error) {
+	cut := postgres.TimestampzT(cutoff)
+	delJournal := table.RetainedIdentities.DELETE().
+		WHERE(table.RetainedIdentities.DetachedAt.LT(cut))
+	res, err := delJournal.ExecContext(ctx, s.db)
+	if err != nil {
+		return 0, 0, fmt.Errorf("account: reap retained identities: %w", err)
+	}
+	identities, _ = res.RowsAffected()
+
+	expired := postgres.SELECT(table.Accounts.AccountID).
+		FROM(table.Accounts).
+		WHERE(table.Accounts.DeletedAt.IS_NOT_NULL().AND(table.Accounts.DeletedAt.LT(cut)))
+	delFeedback := table.FeedbackMessages.DELETE().
+		WHERE(table.FeedbackMessages.AccountID.IN(expired))
+	fbRes, err := delFeedback.ExecContext(ctx, s.db)
+	if err != nil {
+		return identities, 0, fmt.Errorf("account: reap deleted feedback: %w", err)
+	}
+	feedback, _ = fbRes.RowsAffected()
+
+	clearPII := table.Accounts.UPDATE(table.Accounts.DeletedDisplayName, table.Accounts.LastLoginIP).
+		SET(postgres.NULL, postgres.NULL).
+		WHERE(
+			table.Accounts.DeletedAt.IS_NOT_NULL().
+				AND(table.Accounts.DeletedAt.LT(cut)).
+				AND(table.Accounts.DeletedDisplayName.IS_NOT_NULL().
+					OR(table.Accounts.LastLoginIP.IS_NOT_NULL())),
+		)
+	if _, err := clearPII.ExecContext(ctx, s.db); err != nil {
+		return identities, feedback, fmt.Errorf("account: clear expired dossier PII: %w", err)
+	}
+	return identities, feedback, nil
+}
+
+// RetainedIdentity is one row of the retention journal, for the admin dossier.
+type RetainedIdentity struct {
+	Kind       string
+	ExternalID string
+	Reason     string
+	Confirmed  bool
+	LinkedAt   time.Time
+	DetachedAt time.Time
+}
+
+// RetainedIdentities returns the account's retention-journal rows (the legal dossier of
+// detached credentials), newest detach first, for the admin console.
+func (s *Store) RetainedIdentities(ctx context.Context, accountID uuid.UUID) ([]RetainedIdentity, error) {
+	var rows []model.RetainedIdentities
+	err := postgres.SELECT(table.RetainedIdentities.AllColumns).
+		FROM(table.RetainedIdentities).
+		WHERE(table.RetainedIdentities.AccountID.EQ(postgres.UUID(accountID))).
+		ORDER_BY(table.RetainedIdentities.DetachedAt.DESC()).
+		QueryContext(ctx, s.db, &rows)
+	if err != nil && !errors.Is(err, qrm.ErrNoRows) {
+		return nil, fmt.Errorf("account: retained identities %s: %w", accountID, err)
+	}
+	out := make([]RetainedIdentity, 0, len(rows))
+	for _, r := range rows {
+		out = append(out, RetainedIdentity{
+			Kind: r.Kind, ExternalID: r.ExternalID, Reason: r.Reason,
+			Confirmed: r.Confirmed, LinkedAt: r.LinkedAt, DetachedAt: r.DetachedAt,
+		})
+	}
+	return out, nil
+}
+
+// DeletionInfo is a tombstoned account's dossier header, for the admin console.
+type DeletionInfo struct {
+	DeletedAt          *time.Time
+	DeletedDisplayName string
+	LastLoginAt        *time.Time
+	LastLoginIP        string
+}
+
+// DeletionInfo reads the account's deletion tombstone + last-login dossier fields.
+func (s *Store) DeletionInfo(ctx context.Context, accountID uuid.UUID) (DeletionInfo, error) {
+	var row model.Accounts
+	err := postgres.SELECT(
+		table.Accounts.DeletedAt, table.Accounts.DeletedDisplayName,
+		table.Accounts.LastLoginAt, table.Accounts.LastLoginIP,
+	).FROM(table.Accounts).
+		WHERE(table.Accounts.AccountID.EQ(postgres.UUID(accountID))).
+		QueryContext(ctx, s.db, &row)
+	if err != nil {
+		if errors.Is(err, qrm.ErrNoRows) {
+			return DeletionInfo{}, ErrNotFound
+		}
+		return DeletionInfo{}, fmt.Errorf("account: deletion info %s: %w", accountID, err)
+	}
+	info := DeletionInfo{DeletedAt: row.DeletedAt, LastLoginAt: row.LastLoginAt}
+	if row.DeletedDisplayName != nil {
+		info.DeletedDisplayName = *row.DeletedDisplayName
+	}
+	if row.LastLoginIP != nil {
+		info.LastLoginIP = *row.LastLoginIP
+	}
+	return info, nil
+}
+
+// RetentionReaper periodically purges expired account-deletion retention data via
+// Store.ReapExpiredRetention, mirroring GuestReaper: one background goroutine started once
+// from main.
+type RetentionReaper struct {
+	store *Store
+	ttl   time.Duration
+	clock func() time.Time
+	log   *zap.Logger
+}
+
+// NewRetentionReaper constructs a reaper purging retention data older than ttl. log may be
+// nil.
+func NewRetentionReaper(store *Store, ttl time.Duration, log *zap.Logger) *RetentionReaper {
+	if log == nil {
+		log = zap.NewNop()
+	}
+	return &RetentionReaper{
+		store: store,
+		ttl:   ttl,
+		clock: func() time.Time { return time.Now().UTC() },
+		log:   log,
+	}
+}
+
+// Run purges expired retention data on each tick until ctx is cancelled.
+func (r *RetentionReaper) Run(ctx context.Context, interval time.Duration) {
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			idn, fb, err := r.store.ReapExpiredRetention(ctx, r.clock().Add(-r.ttl))
+			if err != nil {
+				r.log.Warn("retention reap failed", zap.Error(err))
+			} else if idn > 0 || fb > 0 {
+				r.log.Info("reaped expired retention", zap.Int64("identities", idn), zap.Int64("feedback", fb))
+			}
+		}
+	}
+}

backend/internal/account/userlist.go

@@ -19,6 +19,9 @@ type UserListItem struct {
 	PreferredLanguage string
 	IsGuest           bool
 	IsRobot           bool
+	// IsDeleted marks a tombstoned account (deleted_at set), shown as a badge — a search
+	// spans both lists, so a result can be either live or deleted.
+	IsDeleted bool
 	// FlaggedHighRateAt is the soft high-rate marker (zero when unflagged), shown
 	// as a badge in the console list.
 	FlaggedHighRateAt time.Time
@@ -26,13 +29,17 @@ type UserListItem struct {
 }
 
 // UserFilter narrows the admin user list: Robots selects robot accounts (otherwise the
-// non-robot "people"); NameMask and ExternalIDMask are glob masks ('*' = any run, '?' =
-// one char) matched case-insensitively against the display name / any identity's external
-// id. An empty mask means no filter on that field.
+// non-robot "people"); Deleted selects tombstoned accounts (every other scope hides them);
+// NameMask and ExternalIDMask are glob masks ('*' = any run, '?' = one char) matched
+// case-insensitively against the display name / any identity's external id; EmailExact is a
+// strict (exact) match against an account's email identity. An empty value means no filter
+// on that field.
 type UserFilter struct {
 	Robots         bool
+	Deleted        bool
 	NameMask       string
 	ExternalIDMask string
+	EmailExact     string
 }
 
 // robotExists is the correlated subquery testing whether account a is a robot.
@@ -51,17 +58,42 @@ func (s *Store) IsRobot(ctx context.Context, accountID uuid.UUID) (bool, error)
 	return ok, nil
 }
 
-// userListWhere builds the shared WHERE clause and its positional args (from $1).
+// userListWhere builds the shared WHERE clause and its positional args (from $1). On the
+// Robots tab it lists/searches robots only. Otherwise a search (any of the name /
+// external-id / email filters) spans live and deleted people alike — never robots — so the
+// operator finds a match from one query regardless of the People / Deleted tab; the search
+// also looks in the retention journal, so a deleted account is still found by the email /
+// external id it held (those rows moved from identities to retained_identities on deletion)
+// and by its retained real name. With no search, the People / Deleted tab scope applies.
 func userListWhere(f UserFilter) (string, []any) {
-	args := []any{f.Robots}
-	where := robotExists + ` = $1`
-	if name := LikePattern(f.NameMask); name != "" {
-		args = append(args, name)
-		where += fmt.Sprintf(` AND a.display_name ILIKE $%d ESCAPE '\'`, len(args))
+	name := LikePattern(f.NameMask)
+	ext := LikePattern(f.ExternalIDMask)
+	email := strings.ToLower(strings.TrimSpace(f.EmailExact))
+	searching := name != "" || ext != "" || email != ""
+
+	var args []any
+	var where string
+	switch {
+	case f.Robots:
+		where = robotExists + ` = true`
+	case searching:
+		where = robotExists + ` = false`
+	case f.Deleted:
+		where = robotExists + ` = false AND a.deleted_at IS NOT NULL`
+	default:
+		where = robotExists + ` = false AND a.deleted_at IS NULL`
 	}
-	if ext := LikePattern(f.ExternalIDMask); ext != "" {
+	if name != "" {
+		args = append(args, name)
+		where += fmt.Sprintf(` AND (a.display_name ILIKE $%d ESCAPE '\' OR a.deleted_display_name ILIKE $%d ESCAPE '\')`, len(args), len(args))
+	}
+	if ext != "" {
 		args = append(args, ext)
-		where += fmt.Sprintf(` AND EXISTS (SELECT 1 FROM backend.identities i WHERE i.account_id = a.account_id AND i.external_id ILIKE $%d ESCAPE '\')`, len(args))
+		where += fmt.Sprintf(` AND (EXISTS (SELECT 1 FROM backend.identities i WHERE i.account_id = a.account_id AND i.external_id ILIKE $%d ESCAPE '\') OR EXISTS (SELECT 1 FROM backend.retained_identities r WHERE r.account_id = a.account_id AND r.external_id ILIKE $%d ESCAPE '\'))`, len(args), len(args))
+	}
+	if email != "" {
+		args = append(args, email)
+		where += fmt.Sprintf(` AND (EXISTS (SELECT 1 FROM backend.identities i WHERE i.account_id = a.account_id AND i.kind = 'email' AND i.external_id = $%d) OR EXISTS (SELECT 1 FROM backend.retained_identities r WHERE r.account_id = a.account_id AND r.kind = 'email' AND r.external_id = $%d))`, len(args), len(args))
 	}
 	return where, args
 }
@@ -69,7 +101,7 @@ func userListWhere(f UserFilter) (string, []any) {
 // ListUsers returns the filtered admin user list, newest first, paginated.
 func (s *Store) ListUsers(ctx context.Context, f UserFilter, limit, offset int) ([]UserListItem, error) {
 	where, args := userListWhere(f)
-	q := `SELECT a.account_id, a.display_name, a.preferred_language, a.is_guest, a.flagged_high_rate_at, a.created_at, ` + robotExists + ` AS is_robot
+	q := `SELECT a.account_id, a.display_name, a.preferred_language, a.is_guest, a.flagged_high_rate_at, a.created_at, ` + robotExists + ` AS is_robot, (a.deleted_at IS NOT NULL) AS is_deleted
 FROM backend.accounts a WHERE ` + where +
 		fmt.Sprintf(` ORDER BY a.created_at DESC LIMIT $%d OFFSET $%d`, len(args)+1, len(args)+2)
 	args = append(args, limit, offset)
@@ -82,7 +114,7 @@ FROM backend.accounts a WHERE ` + where +
 	for rows.Next() {
 		var it UserListItem
 		var flagged sql.NullTime
-		if err := rows.Scan(&it.ID, &it.DisplayName, &it.PreferredLanguage, &it.IsGuest, &flagged, &it.CreatedAt, &it.IsRobot); err != nil {
+		if err := rows.Scan(&it.ID, &it.DisplayName, &it.PreferredLanguage, &it.IsGuest, &flagged, &it.CreatedAt, &it.IsRobot, &it.IsDeleted); err != nil {
 			return nil, fmt.Errorf("account: scan user: %w", err)
 		}
 		if flagged.Valid {

backend/internal/account/variant_seed_test.go

@@ -0,0 +1,37 @@
+package account
+
+import (
+	"slices"
+	"testing"
+)
+
+// TestSeedVariantsFromStartParam covers decoding a promo deep-link start-param into the
+// variant-preference set to seed: a valid "v"-prefixed, "-"-joined label list is cleaned
+// to the canonical order and deduplicated, while anything that is not a variant-seed link
+// or that names an unknown variant yields nil (leaving the account on its defaults).
+func TestSeedVariantsFromStartParam(t *testing.T) {
+	tests := []struct {
+		name  string
+		param string
+		want  []string
+	}{
+		{"english promo", "verudit_ru-scrabble_en", []string{"erudit_ru", "scrabble_en"}},
+		{"single variant", "vscrabble_en", []string{"scrabble_en"}},
+		{"canonical order regardless of payload order", "vscrabble_en-erudit_ru", []string{"erudit_ru", "scrabble_en"}},
+		{"deduplicated", "verudit_ru-erudit_ru", []string{"erudit_ru"}},
+		{"empty", "", nil},
+		{"prefix only", "v", nil},
+		{"routing game link is not a seed", "g0190abcd", nil},
+		{"friend code link is not a seed", "f123456", nil},
+		{"unknown variant rejected", "vscrabble_de", nil},
+		{"one unknown label rejects the whole set", "verudit_ru-scrabble_de", nil},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := SeedVariantsFromStartParam(tc.param)
+			if !slices.Equal(got, tc.want) {
+				t.Errorf("SeedVariantsFromStartParam(%q) = %v, want %v", tc.param, got, tc.want)
+			}
+		})
+	}
+}

backend/internal/accountdelete/delete.go

@@ -0,0 +1,223 @@
+// Package accountdelete deactivates an account as legal retention, not erasure: it keeps
+// the account row as a tombstone (its chat/complaint foreign keys have no cascade, so a
+// hard delete is impossible) while journalling and freeing the account's credentials,
+// anonymising the live surfaces, and dropping the account's own social/ephemeral rows.
+// The retained_identities journal plus the tombstone (deleted_at, deleted_display_name,
+// last_login_at/ip) form the admin/legal dossier; messages are deliberately kept. Session
+// revocation and active-game forfeit are orchestrated one layer up (they need the session
+// cache and the game service). See docs/ARCHITECTURE.md §9.1 and the retention TTL reaper.
+package accountdelete
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/go-jet/jet/v2/postgres"
+	"github.com/go-jet/jet/v2/qrm"
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/postgres/jet/backend/model"
+	"scrabble/backend/internal/postgres/jet/backend/table"
+)
+
+// AnonymizedName is the label a deleted account shows to opponents. Display names are
+// stored strings resolved identically for every viewer (no per-viewer localisation in this
+// codebase), so a single canonical label is used. The brackets are deliberate: the
+// editable-name rule (account.displayNameRe) forbids them, so a live player can never set a
+// name that impersonates a deleted account.
+const AnonymizedName = "[Deleted]"
+
+// retainDelete is the retained_identities reason written when a credential is journalled
+// because its account is being deleted.
+const retainDelete = "delete"
+
+// Deleter performs the SQL-atomic part of account deletion over a Postgres handle.
+type Deleter struct {
+	db  *sql.DB
+	now func() time.Time
+}
+
+// NewDeleter constructs a Deleter over db.
+func NewDeleter(db *sql.DB) *Deleter {
+	return &Deleter{db: db, now: func() time.Time { return time.Now().UTC() }}
+}
+
+// AnonymizeAndTombstone retires accountID atomically: it journals every live identity into
+// retained_identities (reason=delete) then removes them so the credentials free for reuse,
+// snapshots the real display name into deleted_display_name and scrubs the live one to
+// AnonymizedName, sets deleted_at, anonymises the account's game-seat snapshots, and drops
+// its friendships, blocks, invitations, friend codes, drafts and pending codes. Chat,
+// feedback and complaints are kept (the surviving tombstone keeps their no-cascade foreign
+// keys valid). It is idempotent-safe on an already-tombstoned account (re-journalling
+// nothing, since the identities are already gone).
+func (d *Deleter) AnonymizeAndTombstone(ctx context.Context, accountID uuid.UUID) error {
+	now := d.now()
+	return withTx(ctx, d.db, func(tx *sql.Tx) error {
+		if err := journalAndDropIdentities(ctx, tx, accountID, now); err != nil {
+			return err
+		}
+		if err := tombstone(ctx, tx, accountID, now); err != nil {
+			return err
+		}
+		if _, err := table.GamePlayers.UPDATE(table.GamePlayers.DisplayName).
+			SET(postgres.String(AnonymizedName)).
+			WHERE(table.GamePlayers.AccountID.EQ(postgres.UUID(accountID))).
+			ExecContext(ctx, tx); err != nil {
+			return fmt.Errorf("accountdelete: anonymise seats: %w", err)
+		}
+		return dropSocialAndEphemerals(ctx, tx, accountID)
+	})
+}
+
+// dropAllRobotGamesSQL deletes every game in which the account plays and no other seat is a
+// human — a robot seat is one whose account holds a 'robot' identity, so this covers both
+// honest vs-AI games and disguised auto-match substitutes. The game rows are deleted; their
+// moves/chat/players/complaints fall away through ON DELETE CASCADE.
+const dropAllRobotGamesSQL = `
+DELETE FROM games g
+WHERE EXISTS (
+    SELECT 1 FROM game_players p WHERE p.game_id = g.game_id AND p.account_id = $1
+) AND NOT EXISTS (
+    SELECT 1 FROM game_players o
+    WHERE o.game_id = g.game_id AND o.account_id <> $1
+      AND NOT EXISTS (
+          SELECT 1 FROM identities i WHERE i.account_id = o.account_id AND i.kind = 'robot'
+      )
+)`
+
+// DropAllRobotGames deletes the account's games that have no human opponent (solo vs-AI or
+// auto-match-robot games), returning how many were removed. Games with any human seat are
+// kept — their seat is anonymised by AnonymizeAndTombstone instead. Run it after the
+// account's active games are resigned, so no live game is removed under the robot driver.
+func (d *Deleter) DropAllRobotGames(ctx context.Context, accountID uuid.UUID) (int64, error) {
+	res, err := d.db.ExecContext(ctx, dropAllRobotGamesSQL, accountID)
+	if err != nil {
+		return 0, fmt.Errorf("accountdelete: drop all-robot games: %w", err)
+	}
+	n, err := res.RowsAffected()
+	if err != nil {
+		return 0, fmt.Errorf("accountdelete: dropped games count: %w", err)
+	}
+	return n, nil
+}
+
+// journalAndDropIdentities copies the account's live identities into the retention journal
+// (reason=delete) and then removes them, freeing each (kind, external_id) for reuse.
+func journalAndDropIdentities(ctx context.Context, tx *sql.Tx, accountID uuid.UUID, now time.Time) error {
+	var ids []model.Identities
+	err := postgres.SELECT(table.Identities.AllColumns).
+		FROM(table.Identities).
+		WHERE(table.Identities.AccountID.EQ(postgres.UUID(accountID))).
+		QueryContext(ctx, tx, &ids)
+	if err != nil && !errors.Is(err, qrm.ErrNoRows) {
+		return fmt.Errorf("accountdelete: load identities: %w", err)
+	}
+	for _, id := range ids {
+		rid, err := uuid.NewV7()
+		if err != nil {
+			return fmt.Errorf("accountdelete: new retained id: %w", err)
+		}
+		ins := table.RetainedIdentities.INSERT(
+			table.RetainedIdentities.RetainedID, table.RetainedIdentities.AccountID,
+			table.RetainedIdentities.Kind, table.RetainedIdentities.ExternalID,
+			table.RetainedIdentities.Confirmed, table.RetainedIdentities.LinkedAt,
+			table.RetainedIdentities.DetachedAt, table.RetainedIdentities.Reason,
+		).VALUES(rid, accountID, id.Kind, id.ExternalID, id.Confirmed, id.CreatedAt, now, retainDelete)
+		if _, err := ins.ExecContext(ctx, tx); err != nil {
+			return fmt.Errorf("accountdelete: retain identity %s: %w", id.Kind, err)
+		}
+	}
+	if _, err := table.Identities.DELETE().
+		WHERE(table.Identities.AccountID.EQ(postgres.UUID(accountID))).
+		ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("accountdelete: delete identities: %w", err)
+	}
+	return nil
+}
+
+// tombstone marks the account deleted, snapshotting the real display name into
+// deleted_display_name (evaluated from the old row) before scrubbing the live one.
+func tombstone(ctx context.Context, tx *sql.Tx, accountID uuid.UUID, now time.Time) error {
+	upd := table.Accounts.UPDATE(
+		table.Accounts.DeletedAt, table.Accounts.DeletedDisplayName,
+		table.Accounts.DisplayName, table.Accounts.UpdatedAt,
+	).SET(
+		postgres.TimestampzT(now), table.Accounts.DisplayName,
+		postgres.String(AnonymizedName), postgres.TimestampzT(now),
+	).WHERE(table.Accounts.AccountID.EQ(postgres.UUID(accountID)))
+	if _, err := upd.ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("accountdelete: tombstone account: %w", err)
+	}
+	return nil
+}
+
+// dropSocialAndEphemerals removes the account's own friendships, blocks, invitations
+// (as inviter and as invitee), friend codes, drafts and pending confirm-codes. These are
+// the deleting user's private data with no dossier value; chat and feedback are kept.
+func dropSocialAndEphemerals(ctx context.Context, tx *sql.Tx, accountID uuid.UUID) error {
+	id := postgres.UUID(accountID)
+	// Friendships and blocks are two-account edges keyed on either endpoint.
+	if _, err := table.Friendships.DELETE().
+		WHERE(table.Friendships.RequesterID.EQ(id).OR(table.Friendships.AddresseeID.EQ(id))).
+		ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("accountdelete: delete friendships: %w", err)
+	}
+	if _, err := table.Blocks.DELETE().
+		WHERE(table.Blocks.BlockerID.EQ(id).OR(table.Blocks.BlockedID.EQ(id))).
+		ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("accountdelete: delete blocks: %w", err)
+	}
+	// Invitations: drop the account's invitee rows, then its own invitations' invitees and
+	// the invitations themselves (children first, to respect the foreign key).
+	if _, err := table.GameInvitationInvitees.DELETE().
+		WHERE(table.GameInvitationInvitees.AccountID.EQ(id)).
+		ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("accountdelete: delete invitee rows: %w", err)
+	}
+	ownInvitations := postgres.SELECT(table.GameInvitations.InvitationID).
+		FROM(table.GameInvitations).
+		WHERE(table.GameInvitations.InviterID.EQ(id))
+	if _, err := table.GameInvitationInvitees.DELETE().
+		WHERE(table.GameInvitationInvitees.InvitationID.IN(ownInvitations)).
+		ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("accountdelete: delete own invitation invitees: %w", err)
+	}
+	if _, err := table.GameInvitations.DELETE().
+		WHERE(table.GameInvitations.InviterID.EQ(id)).
+		ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("accountdelete: delete invitations: %w", err)
+	}
+	// Ephemerals: friend codes, move drafts, pending confirm-codes.
+	if _, err := table.FriendCodes.DELETE().
+		WHERE(table.FriendCodes.AccountID.EQ(id)).ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("accountdelete: delete friend codes: %w", err)
+	}
+	if _, err := table.GameDrafts.DELETE().
+		WHERE(table.GameDrafts.AccountID.EQ(id)).ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("accountdelete: delete drafts: %w", err)
+	}
+	if _, err := table.EmailConfirmations.DELETE().
+		WHERE(table.EmailConfirmations.AccountID.EQ(id)).ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("accountdelete: delete confirmations: %w", err)
+	}
+	return nil
+}
+
+// withTx runs fn inside a transaction, committing on success and rolling back on error.
+func withTx(ctx context.Context, db *sql.DB, fn func(tx *sql.Tx) error) error {
+	tx, err := db.BeginTx(ctx, nil)
+	if err != nil {
+		return fmt.Errorf("accountdelete: begin tx: %w", err)
+	}
+	if err := fn(tx); err != nil {
+		_ = tx.Rollback()
+		return err
+	}
+	if err := tx.Commit(); err != nil {
+		return fmt.Errorf("accountdelete: commit tx: %w", err)
+	}
+	return nil
+}

backend/internal/accountmerge/merge.go

@@ -27,6 +27,11 @@ import (
 // without taking a dependency on the game package.
 const statusActive = "active"
 
+// retainReasonMerge is the retained_identities.reason for a credential dropped by a merge
+// collision (both accounts held the same kind). It mirrors the account package's retain
+// reasons, kept local to avoid importing that package's unexported constants.
+const retainReasonMerge = "merge"
+
 // Friendship statuses, highest precedence first, mirroring internal/social.
 const (
 	friendAccepted = "accepted"
@@ -46,8 +51,24 @@ var ErrSameAccount = errors.New("accountmerge: primary and secondary are the sam
 type Merger struct {
 	db  *sql.DB
 	now func() time.Time
+	// payments, when set, merges the two accounts' chip segments and benefits by origin inside
+	// the merge transaction (SetPayments). Nil leaves payments untouched (tests that do not
+	// exercise the wallet).
+	payments PaymentsMerger
 }
 
+// PaymentsMerger is the payments surface the account merge enlists: fold the secondary's
+// segments and benefits into the primary within the merge transaction, then invalidate the
+// affected read caches after the commit. *payments.Service satisfies it.
+type PaymentsMerger interface {
+	MergeTx(ctx context.Context, tx *sql.Tx, primary, secondary uuid.UUID) error
+	Invalidate(ids ...uuid.UUID)
+}
+
+// SetPayments installs the payments merge hook. It must be called during startup wiring; the
+// default (nil) merges no wallet state.
+func (m *Merger) SetPayments(p PaymentsMerger) { m.payments = p }
+
 // NewMerger constructs a Merger over db.
 func NewMerger(db *sql.DB) *Merger {
 	return &Merger{db: db, now: func() time.Time { return time.Now().UTC() }}
@@ -62,7 +83,7 @@ func (m *Merger) Merge(ctx context.Context, primary, secondary uuid.UUID) error
 		return ErrSameAccount
 	}
 	now := m.now()
-	return withTx(ctx, m.db, func(tx *sql.Tx) error {
+	if err := withTx(ctx, m.db, func(tx *sql.Tx) error {
 		if err := guardActiveSharedGame(ctx, tx, primary, secondary); err != nil {
 			return err
 		}
@@ -75,6 +96,9 @@ func (m *Merger) Merge(ctx context.Context, primary, secondary uuid.UUID) error
 		if err := mergeAccountFields(ctx, tx, primary, secondary, now); err != nil {
 			return err
 		}
+		if err := dedupeIdentities(ctx, tx, primary, secondary); err != nil {
+			return err
+		}
 		if err := reassignColumn(ctx, tx, table.Identities, table.Identities.AccountID, primary, secondary); err != nil {
 			return fmt.Errorf("accountmerge: identities: %w", err)
 		}
@@ -99,8 +123,21 @@ func (m *Merger) Merge(ctx context.Context, primary, secondary uuid.UUID) error
 		if err := deleteEphemerals(ctx, tx, secondary); err != nil {
 			return err
 		}
+		if m.payments != nil {
+			if err := m.payments.MergeTx(ctx, tx, primary, secondary); err != nil {
+				return fmt.Errorf("accountmerge: payments: %w", err)
+			}
+		}
 		return tombstone(ctx, tx, primary, secondary, now)
-	})
+	}); err != nil {
+		return err
+	}
+	// The payments read cache is invalidated only after the merge commits, so a read racing the
+	// transaction cannot re-cache pre-merge state (both accounts' rows are moved or dropped).
+	if m.payments != nil {
+		m.payments.Invalidate(primary, secondary)
+	}
+	return nil
 }
 
 // guardActiveSharedGame returns ErrActiveGameConflict when primary and secondary
@@ -240,25 +277,16 @@ func mergeBestMoves(ctx context.Context, tx *sql.Tx, primary, secondary uuid.UUI
 	return nil
 }
 
-// mergeAccountFields adds secondary's hint wallet to primary and ORs the paid flag;
-// all other profile fields stay the primary's.
-func mergeAccountFields(ctx context.Context, tx *sql.Tx, primary, secondary uuid.UUID, now time.Time) error {
-	var sec model.Accounts
-	if err := postgres.SELECT(table.Accounts.AllColumns).
-		FROM(table.Accounts).
-		WHERE(table.Accounts.AccountID.EQ(postgres.UUID(secondary))).
-		QueryContext(ctx, tx, &sec); err != nil {
-		return fmt.Errorf("accountmerge: load secondary account: %w", err)
-	}
-	upd := table.Accounts.UPDATE(
-		table.Accounts.HintBalance, table.Accounts.PaidAccount, table.Accounts.UpdatedAt,
-	).SET(
-		table.Accounts.HintBalance.ADD(postgres.Int(int64(sec.HintBalance))),
-		table.Accounts.PaidAccount.OR(postgres.Bool(sec.PaidAccount)),
-		postgres.TimestampzT(now),
-	).WHERE(table.Accounts.AccountID.EQ(postgres.UUID(primary)))
+// mergeAccountFields bumps the primary account's updated_at to reflect the merge. The former
+// hint-wallet and paid-flag merge moved to the payments domain, where segments and benefits
+// merge by origin (see the payments MergeTx step and docs/PAYMENTS.md §6); the legacy
+// accounts.hint_balance / paid_account columns are deprecated and no longer read or written.
+func mergeAccountFields(ctx context.Context, tx *sql.Tx, primary, _ uuid.UUID, now time.Time) error {
+	upd := table.Accounts.UPDATE(table.Accounts.UpdatedAt).
+		SET(postgres.TimestampzT(now)).
+		WHERE(table.Accounts.AccountID.EQ(postgres.UUID(primary)))
 	if _, err := upd.ExecContext(ctx, tx); err != nil {
-		return fmt.Errorf("accountmerge: update primary account: %w", err)
+		return fmt.Errorf("accountmerge: touch primary account: %w", err)
 	}
 	return nil
 }
@@ -300,6 +328,77 @@ func reassignColumn(ctx context.Context, tx *sql.Tx, tbl postgres.Table, col pos
 	return err
 }
 
+// dedupeIdentities resolves a same-kind identity collision before the blanket identity
+// reassign: when both accounts already hold an identity of the same kind (e.g. each has a
+// confirmed email — reachable when two email-bearing accounts merge), the primary keeps
+// its own and the secondary's is journaled to retained_identities (reason=merge) and
+// removed. Without this the blanket reassign would leave the survivor with two identities
+// of one kind (there is no per-account-kind unique on identities), which the profile and
+// the retention dossier both treat as singular. Non-colliding identities are untouched and
+// move with the blanket reassign.
+func dedupeIdentities(ctx context.Context, tx *sql.Tx, primary, secondary uuid.UUID) error {
+	var prows []model.Identities
+	if err := postgres.SELECT(table.Identities.Kind).
+		FROM(table.Identities).
+		WHERE(table.Identities.AccountID.EQ(postgres.UUID(primary))).
+		QueryContext(ctx, tx, &prows); err != nil && !errors.Is(err, qrm.ErrNoRows) {
+		return fmt.Errorf("accountmerge: primary identity kinds: %w", err)
+	}
+	occupied := make(map[string]struct{}, len(prows))
+	for _, r := range prows {
+		occupied[r.Kind] = struct{}{}
+	}
+	if len(occupied) == 0 {
+		return nil
+	}
+	var srows []model.Identities
+	if err := postgres.SELECT(
+		table.Identities.Kind, table.Identities.ExternalID,
+		table.Identities.Confirmed, table.Identities.CreatedAt,
+	).FROM(table.Identities).
+		WHERE(table.Identities.AccountID.EQ(postgres.UUID(secondary))).
+		QueryContext(ctx, tx, &srows); err != nil && !errors.Is(err, qrm.ErrNoRows) {
+		return fmt.Errorf("accountmerge: secondary identities: %w", err)
+	}
+	for _, s := range srows {
+		if _, dup := occupied[s.Kind]; !dup {
+			continue
+		}
+		if err := retainMergedIdentity(ctx, tx, secondary, s); err != nil {
+			return err
+		}
+		del := table.Identities.DELETE().WHERE(
+			table.Identities.AccountID.EQ(postgres.UUID(secondary)).
+				AND(table.Identities.Kind.EQ(postgres.String(s.Kind))).
+				AND(table.Identities.ExternalID.EQ(postgres.String(s.ExternalID))),
+		)
+		if _, err := del.ExecContext(ctx, tx); err != nil {
+			return fmt.Errorf("accountmerge: drop colliding %s identity: %w", s.Kind, err)
+		}
+	}
+	return nil
+}
+
+// retainMergedIdentity appends a retained_identities row for a secondary identity dropped
+// by a merge collision (reason=merge), preserving it in the legal dossier. It mirrors
+// account.retainIdentityTx, which is unexported; detached_at falls to the column default.
+func retainMergedIdentity(ctx context.Context, tx *sql.Tx, accountID uuid.UUID, id model.Identities) error {
+	rid, err := uuid.NewV7()
+	if err != nil {
+		return fmt.Errorf("accountmerge: new retained id: %w", err)
+	}
+	ins := table.RetainedIdentities.INSERT(
+		table.RetainedIdentities.RetainedID, table.RetainedIdentities.AccountID,
+		table.RetainedIdentities.Kind, table.RetainedIdentities.ExternalID,
+		table.RetainedIdentities.Confirmed, table.RetainedIdentities.LinkedAt,
+		table.RetainedIdentities.Reason,
+	).VALUES(rid, accountID, id.Kind, id.ExternalID, id.Confirmed, id.CreatedAt, retainReasonMerge)
+	if _, err := ins.ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("accountmerge: retain merged %s identity: %w", id.Kind, err)
+	}
+	return nil
+}
+
 // friendRank ranks a friendship status for dedupe precedence (higher wins).
 func friendRank(status string) int {
 	switch status {

backend/internal/adminalert/notify.go

@@ -0,0 +1,115 @@
+// Package adminalert emails the operator when new player feedback or word complaints
+// arrive, coalescing a burst into a single digest per interval so a flood is one email,
+// not N. It is inert unless an admin sender and recipient are configured. The sender is
+// distinct from the user-facing confirm-code From, and the recipient may be several
+// comma-separated addresses (the mailer splits them).
+package adminalert
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	"go.uber.org/zap"
+
+	"scrabble/backend/internal/account"
+)
+
+// FeedbackCounter counts feedback created since a time (satisfied by feedback.Service).
+type FeedbackCounter interface {
+	CountSince(ctx context.Context, since time.Time) (int, error)
+}
+
+// ComplaintCounter counts word complaints filed since a time (satisfied by game.Service).
+type ComplaintCounter interface {
+	CountComplaintsSince(ctx context.Context, since time.Time) (int, error)
+}
+
+// Notifier polls for new feedback and complaints and emails the operator a digest.
+type Notifier struct {
+	mailer     account.Mailer
+	feedback   FeedbackCounter
+	complaints ComplaintCounter
+	from       string
+	to         string
+	clock      func() time.Time
+	log        *zap.Logger
+	last       time.Time
+}
+
+// New constructs a Notifier. from and to are the alert sender and recipient(s); log may be
+// nil. The watermark starts at "now", so only items arriving after start-up are reported. The
+// digest deliberately carries no admin-console link — an admin URL must never travel in an
+// email, where a mail provider could cache or index it.
+func New(mailer account.Mailer, fb FeedbackCounter, cp ComplaintCounter, from, to string, log *zap.Logger) *Notifier {
+	if log == nil {
+		log = zap.NewNop()
+	}
+	return &Notifier{
+		mailer: mailer, feedback: fb, complaints: cp, from: from, to: to,
+		clock: func() time.Time { return time.Now().UTC() }, log: log, last: time.Now().UTC(),
+	}
+}
+
+// Run polls on each tick until ctx is cancelled.
+func (n *Notifier) Run(ctx context.Context, interval time.Duration) {
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			n.tick(ctx)
+		}
+	}
+}
+
+// tick counts what arrived since the last watermark and, if anything did, emails one
+// digest. The watermark only advances after a successful send (or a quiet tick), so a
+// transient send failure is retried on the next tick — the counts simply grow.
+func (n *Notifier) tick(ctx context.Context) {
+	now := n.clock()
+	fb, err := n.feedback.CountSince(ctx, n.last)
+	if err != nil {
+		n.log.Warn("admin alert: count feedback failed", zap.Error(err))
+		return
+	}
+	cp, err := n.complaints.CountComplaintsSince(ctx, n.last)
+	if err != nil {
+		n.log.Warn("admin alert: count complaints failed", zap.Error(err))
+		return
+	}
+	if fb == 0 && cp == 0 {
+		n.last = now
+		return
+	}
+	if err := n.mailer.Send(ctx, n.digest(fb, cp)); err != nil {
+		n.log.Warn("admin alert: send failed", zap.Error(err))
+		return
+	}
+	n.log.Info("admin alert sent", zap.Int("feedback", fb), zap.Int("complaints", cp))
+	n.last = now
+}
+
+// digest builds the operator alert email for fb new feedback and cp new complaints.
+func (n *Notifier) digest(fb, cp int) account.Message {
+	var parts []string
+	if fb > 0 {
+		parts = append(parts, fmt.Sprintf("%d new feedback message(s)", fb))
+	}
+	if cp > 0 {
+		parts = append(parts, fmt.Sprintf("%d new word complaint(s)", cp))
+	}
+	summary := strings.Join(parts, ", ")
+	// No admin-console link in the body: an admin URL must never travel in an email (a mail
+	// provider could cache or index it). The operator opens the console directly.
+	text := summary + "."
+	return account.Message{
+		From:    n.from,
+		To:      n.to,
+		Subject: "Erudit — " + summary,
+		Text:    text,
+	}
+}

backend/internal/adminalert/notify_test.go

@@ -0,0 +1,57 @@
+package adminalert
+
+import (
+	"context"
+	"strings"
+	"testing"
+	"time"
+
+	"scrabble/backend/internal/account"
+)
+
+// The fakes ignore the watermark and return a fixed count, which is all the digest logic
+// needs.
+type fbCounter struct{ n int }
+
+func (f fbCounter) CountSince(context.Context, time.Time) (int, error) { return f.n, nil }
+
+type cpCounter struct{ n int }
+
+func (c cpCounter) CountComplaintsSince(context.Context, time.Time) (int, error) { return c.n, nil }
+
+type recordingMailer struct{ sent []account.Message }
+
+func (m *recordingMailer) Send(_ context.Context, msg account.Message) error {
+	m.sent = append(m.sent, msg)
+	return nil
+}
+
+func TestNotifierSkipsWhenNothingNew(t *testing.T) {
+	mailer := &recordingMailer{}
+	n := New(mailer, fbCounter{0}, cpCounter{0}, "alerts@erudit-game.ru", "op@x.ru", nil)
+	n.tick(context.Background())
+	if len(mailer.sent) != 0 {
+		t.Fatalf("sent %d emails, want 0 when nothing is new", len(mailer.sent))
+	}
+}
+
+func TestNotifierDigestsNewItems(t *testing.T) {
+	mailer := &recordingMailer{}
+	n := New(mailer, fbCounter{2}, cpCounter{1}, "alerts@erudit-game.ru", "op@x.ru, two@x.ru", nil)
+	n.tick(context.Background())
+	if len(mailer.sent) != 1 {
+		t.Fatalf("sent %d emails, want 1 digest", len(mailer.sent))
+	}
+	msg := mailer.sent[0]
+	if msg.From != "alerts@erudit-game.ru" || msg.To != "op@x.ru, two@x.ru" {
+		t.Errorf("digest addressing = From %q To %q", msg.From, msg.To)
+	}
+	if !strings.Contains(msg.Subject, "2 new feedback") || !strings.Contains(msg.Subject, "1 new word complaint") {
+		t.Errorf("digest subject = %q, want the feedback + complaint counts", msg.Subject)
+	}
+	// The digest must never carry an admin-console link — an admin URL in an email is a leak
+	// (mail providers cache/index it).
+	if strings.Contains(msg.Text, "/_gm") || strings.Contains(strings.ToLower(msg.Text), "admin console") {
+		t.Errorf("digest body = %q, must not carry an admin-console link", msg.Text)
+	}
+}

backend/internal/adminconsole/assets/console.css

@@ -193,3 +193,24 @@ code { background: var(--bg); padding: 0.05rem 0.3rem; border-radius: 4px; }
 .replay-log { margin: 0.4rem 0 0; padding-left: 1.4rem; max-height: 14rem; overflow: auto; font-size: 0.85rem; }
 .replay-log li { color: var(--ink-dim); padding: 0.1rem 0; }
 .replay-log li.cur { color: var(--ink); font-weight: 600; }
+
+/* Banner colour override editor + live preview (banner_detail). The override
+   fieldsets group the enable toggle with the native colour swatches; the preview
+   renders a sample strip on both themes from those inputs (see the inline script). */
+.ovr { border: 1px solid var(--line); border-radius: 6px; padding: 0.3rem 0.8rem 0.7rem; margin: 0.2rem 0; }
+.ovr legend { padding: 0 0.3rem; font-size: 0.85rem; color: var(--ink); }
+.ovr legend label { flex-direction: row; align-items: center; gap: 0.4rem; color: var(--ink); }
+.ovr .note { margin: 0.2rem 0 0.4rem; }
+.ovr .swatches { display: flex; flex-wrap: wrap; gap: 1rem; }
+.ovr .swatches label { flex-direction: column; gap: 0.25rem; align-items: flex-start; }
+.ovr input[type=color] { width: 3rem; height: 1.8rem; padding: 0; border: 1px solid var(--line); border-radius: 4px; background: var(--bg); cursor: pointer; }
+.ovr input[type=color]:disabled { opacity: 0.4; cursor: default; }
+.ovr .hex { font-size: 0.72rem; color: var(--ink-dim); font-variant-numeric: tabular-nums; }
+.banner-preview { display: flex; flex-wrap: wrap; gap: 0.8rem; margin: 0.7rem 0 0.2rem; }
+.banner-preview .bp { flex: 1 1 18rem; }
+.banner-preview .bp-label { display: block; font-size: 0.75rem; color: var(--ink-dim); margin-bottom: 0.25rem; }
+.ad-frame { padding: 0.7rem; border-radius: 6px; border: 1px solid var(--line); }
+.ad-frame.light { background: #f4f6f9; }
+.ad-frame.dark { background: #0f1420; }
+.ad-sample { padding: 0.35rem 0.7rem; font-size: 0.85rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
+.ad-sample .ad-link { text-decoration: underline; }

backend/internal/adminconsole/render_test.go

@@ -24,6 +24,7 @@ func TestRendererRendersEveryPage(t *testing.T) {
 		{"dashboard", DashboardView{Accounts: 3, Variants: []VariantVersions{{Variant: "scrabble_en", Latest: "v1", Versions: []string{"v1"}}}}, "Dashboard"},
 		{"users", UsersView{Items: []UserRow{{ID: "a1", DisplayName: "Kaya", FlaggedHighRate: true}}, Pager: NewPager(1, 50, 1)}, "high-rate"},
 		{"user_detail", UserDetailView{ID: "a1", DisplayName: "Kaya", HasStats: true, Stats: StatsRow{Wins: 2}, TelegramID: "123", ConnectorEnabled: true}, "Send Telegram message"},
+		{"user_detail", UserDetailView{ID: "a1", DisplayName: "Kaya", VKID: "494075"}, "vk.com/id494075"},
 		{"user_detail", UserDetailView{ID: "a1", DisplayName: "Kaya", FlaggedHighRateAt: "2026-06-10 12:00"}, "Clear high-rate flag"},
 		{"user_detail", UserDetailView{ID: "a1", DisplayName: "Kaya", Roles: []string{"feedback_banned"}, KnownRoles: []string{"feedback_banned"}}, "feedback_banned"},
 		{"user_detail", UserDetailView{ID: "a1", DisplayName: "Kaya",

backend/internal/adminconsole/templates/pages/banner_detail.gohtml

@@ -11,10 +11,72 @@
 <label>Starts (UTC) <input type="datetime-local" name="starts_at" value="{{.StartsAt}}"></label>
 <label>Ends (UTC) <input type="datetime-local" name="ends_at" value="{{.EndsAt}}"></label>
 <label><input type="checkbox" name="enabled"{{if .Enabled}} checked{{end}}> Enabled</label>
+<fieldset class="ovr">
+<legend><label><input type="checkbox" name="urgent"{{if .Urgent}} checked{{end}}> Urgent</label></legend>
+<p class="note">Shows to <em>everyone</em>, always — bypassing paid accounts, hint wallets and the no-banner role. While any urgent campaign is live it is the only thing the strip shows (other campaigns and the default are suppressed). For system alerts.</p>
+</fieldset>
+<fieldset class="ovr" data-ovr-group>
+<legend><label><input type="checkbox" name="override_all_on" data-ovr="all"{{if .OverrideAllOn}} checked{{end}}> Colour override — all themes</label></legend>
+<div class="swatches">
+<label>Background <input type="color" name="override_bg" value="{{.AllBg}}" data-ovr-color{{if not .OverrideAllOn}} disabled{{end}}><span class="hex"></span></label>
+<label>Text <input type="color" name="override_fg" value="{{.AllFg}}" data-ovr-color{{if not .OverrideAllOn}} disabled{{end}}><span class="hex"></span></label>
+<label>Link <input type="color" name="override_link" value="{{.AllLink}}" data-ovr-color{{if not .OverrideAllOn}} disabled{{end}}><span class="hex"></span></label>
+</div>
+</fieldset>
+<fieldset class="ovr" data-ovr-group>
+<legend><label><input type="checkbox" name="override_dark_on" data-ovr="dark"{{if .OverrideDarkOn}} checked{{end}}> Colour override — dark theme only</label></legend>
+<div class="swatches">
+<label>Background <input type="color" name="override_bg_dark" value="{{.DarkBg}}" data-ovr-color{{if not .OverrideDarkOn}} disabled{{end}}><span class="hex"></span></label>
+<label>Text <input type="color" name="override_fg_dark" value="{{.DarkFg}}" data-ovr-color{{if not .OverrideDarkOn}} disabled{{end}}><span class="hex"></span></label>
+<label>Link <input type="color" name="override_link_dark" value="{{.DarkLink}}" data-ovr-color{{if not .OverrideDarkOn}} disabled{{end}}><span class="hex"></span></label>
+</div>
+</fieldset>
 {{end}}
 <div><button type="submit">Save</button></div>
 </form>
 {{if not .IsDefault}}
+<div class="banner-preview">
+<div class="bp"><span class="bp-label">Light theme</span><div class="ad-frame light"><div class="ad-sample" id="prev-light"><span>Sample banner text — <span class="ad-link">a link</span></span></div></div></div>
+<div class="bp"><span class="bp-label">Dark theme</span><div class="ad-frame dark"><div class="ad-sample" id="prev-dark"><span>Sample banner text — <span class="ad-link">a link</span></span></div></div></div>
+</div>
+<p class="note">Live preview of the strip on both themes. An empty override falls back to the neutral theme colours; the top/bottom border is derived from the background.</p>
+<script>
+(function(){
+  // Neutral fallbacks — mirror ui/src/app.css (--ad-bg / --text-muted / --accent).
+  var TOK={light:{bg:'#e3e7ee',fg:'#6b7280',link:'#2f6df6'},dark:{bg:'#272f3c',fg:'#9aa3b2',link:'#5b8cff'}};
+  function byName(n){return document.querySelector('[name="'+n+'"]');}
+  var allOn=byName('override_all_on'), darkOn=byName('override_dark_on');
+  if(!allOn||!darkOn){return;}
+  var f={ab:byName('override_bg'),af:byName('override_fg'),al:byName('override_link'),db:byName('override_bg_dark'),df:byName('override_fg_dark'),dl:byName('override_link_dark')};
+  var lightEl=document.getElementById('prev-light'), darkEl=document.getElementById('prev-dark');
+  function hexToRgb(h){h=h.replace('#','');return [parseInt(h.slice(0,2),16),parseInt(h.slice(2,4),16),parseInt(h.slice(4,6),16)];}
+  function pad(x){x=Math.max(0,Math.min(255,Math.round(x))).toString(16);return x.length<2?'0'+x:x;}
+  function rgbToHex(r){return '#'+pad(r[0])+pad(r[1])+pad(r[2]);}
+  function mix(a,b,t){return [a[0]+(b[0]-a[0])*t,a[1]+(b[1]-a[1])*t,a[2]+(b[2]-a[2])*t];}
+  function lum(r){return (0.2126*r[0]+0.7152*r[1]+0.0722*r[2])/255;}
+  // Derived border: nudge the background 14% toward black on a light bg, toward white on a dark bg.
+  function border(bg){var r=hexToRgb(bg);return rgbToHex(mix(r, lum(r)>0.5?[0,0,0]:[255,255,255], 0.14));}
+  function paint(el,c){
+    el.style.background=c.bg; el.style.color=c.fg;
+    el.style.borderTop='1px solid '+border(c.bg); el.style.borderBottom='1px solid '+border(c.bg);
+    var a=el.querySelector('.ad-link'); if(a){a.style.color=c.link;}
+  }
+  function resolve(){
+    var light=allOn.checked?{bg:f.ab.value,fg:f.af.value,link:f.al.value}:TOK.light;
+    var dark=darkOn.checked?{bg:f.db.value,fg:f.df.value,link:f.dl.value}
+            :(allOn.checked?{bg:f.ab.value,fg:f.af.value,link:f.al.value}:TOK.dark);
+    paint(lightEl,light); paint(darkEl,dark);
+    document.querySelectorAll('.ovr .swatches label').forEach(function(lab){
+      var inp=lab.querySelector('input[type=color]'), hx=lab.querySelector('.hex');
+      if(inp&&hx){hx.textContent=inp.value;}
+    });
+  }
+  function toggleGroup(chk){chk.closest('fieldset').querySelectorAll('[data-ovr-color]').forEach(function(inp){inp.disabled=!chk.checked;});}
+  [allOn,darkOn].forEach(function(chk){chk.addEventListener('change',function(){toggleGroup(chk);resolve();});});
+  Object.keys(f).forEach(function(k){f[k].addEventListener('input',resolve);});
+  resolve();
+})();
+</script>
 <form class="form" method="post" action="/_gm/banners/{{.ID}}/delete" onsubmit="return confirm('Delete this campaign and its messages?')">
 <button type="submit" class="danger">Delete campaign</button>
 </form>

backend/internal/adminconsole/templates/pages/user_detail.gohtml

@@ -101,6 +101,29 @@
 {{else}}<tr><td colspan="4"><span class="note">no identities (guest)</span></td></tr>{{end}}
 </tbody>
 </table>
+{{if .HasEmail}}
+<form class="form" method="post" action="/_gm/users/{{.ID}}/remove-email" onsubmit="return confirm('Erase the email identity from this account? The address will be freed.')">
+<button type="submit">Erase email</button>
+</form>
+{{end}}
+</section>
+<section class="panel"><h2>Deletion &amp; retention</h2>
+{{if .LastLoginAt}}<p class="note">Last login: {{.LastLoginAt}}{{if .LastLoginIP}} — <code>{{.LastLoginIP}}</code>{{end}}</p>{{end}}
+{{if .Deleted}}<p><span class="warn">Deleted</span> at {{.DeletedAt}}{{if .DeletedName}} — was <code>{{.DeletedName}}</code>{{end}}</p>{{end}}
+{{if .Retained}}
+<h3>Retention journal (legal dossier of detached credentials)</h3>
+<table class="list">
+<thead><tr><th>Kind</th><th>Credential</th><th>Reason</th><th>Detached</th></tr></thead>
+<tbody>
+{{range .Retained}}<tr><td>{{.Kind}}</td><td><code>{{.ExternalID}}</code></td><td>{{.Reason}}</td><td>{{.DetachedAt}}</td></tr>{{end}}
+</tbody>
+</table>
+{{end}}
+{{if not .Deleted}}
+<form class="form" method="post" action="/_gm/users/{{.ID}}/delete" onsubmit="return confirm('Delete this account? Its credentials are journalled and freed, its data anonymised, and its sessions revoked. This cannot be undone.')">
+<button type="submit">Delete user</button>
+</form>
+{{end}}
 </section>
 <section class="panel"><h2>Friends</h2>
 <table class="list">
@@ -142,6 +165,11 @@
 {{else}}<p class="note">connector not configured (set BACKEND_CONNECTOR_ADDR)</p>{{end}}
 </section>
 {{end}}
+{{if .VKID}}
+<section class="panel"><h2>VK</h2>
+<p>VK ID: <code>{{.VKID}}</code> · <a href="https://vk.com/id{{.VKID}}" target="_blank" rel="noopener">open profile</a></p>
+</section>
+{{end}}
 <section class="panel"><h2>Games</h2>
 <table class="list">
 <thead><tr><th>Game</th><th>Variant</th><th>Status</th><th class="num">Players</th><th>Updated</th></tr></thead>

backend/internal/adminconsole/templates/pages/users.gohtml

@@ -2,13 +2,15 @@
 <h1>Users</h1>
 {{with .Data}}
 <nav class="subnav">
-<a href="/_gm/users"{{if not .Robots}} class="active"{{end}}>People</a> ·
+<a href="/_gm/users"{{if and (not .Robots) (not .Deleted)}} class="active"{{end}}>People</a> ·
+<a href="/_gm/users?kind=deleted"{{if .Deleted}} class="active"{{end}}>Deleted</a> ·
 <a href="/_gm/users?kind=robots"{{if .Robots}} class="active"{{end}}>Robots</a>
 </nav>
 <form class="form" method="get" action="/_gm/users">
-{{if .Robots}}<input type="hidden" name="kind" value="robots">{{end}}
+{{if .Robots}}<input type="hidden" name="kind" value="robots">{{end}}{{if .Deleted}}<input type="hidden" name="kind" value="deleted">{{end}}
 <input name="name" value="{{.NameMask}}" placeholder="display name mask (* ?)">
 <input name="ext" value="{{.ExternalIDMask}}" placeholder="external id mask (* ?)">
+<input name="email" value="{{.EmailExact}}" placeholder="email (exact)" type="search">
 <button type="submit">Filter</button>
 </form>
 <table class="list">
@@ -17,7 +19,7 @@
 {{range .Items}}
 <tr>
 <td><a href="/_gm/users/{{.ID}}">{{.ID}}</a></td>
-<td>{{.DisplayName}}{{if .Guest}} <span class="pill">guest</span>{{end}}{{if .FlaggedHighRate}} <span class="pill">high-rate</span>{{end}}</td>
+<td>{{.DisplayName}}{{if .Deleted}} <span class="pill">deleted</span>{{end}}{{if .Guest}} <span class="pill">guest</span>{{end}}{{if .FlaggedHighRate}} <span class="pill">high-rate</span>{{end}}</td>
 <td>{{.Kind}}</td>
 <td>{{.Language}}</td>
 <td>{{.CreatedAt}}</td>

backend/internal/adminconsole/views.go

@@ -60,8 +60,10 @@ type UsersView struct {
 	// be emitted verbatim — interpolated as a plain string it would have its "=" and "&"
 	// percent-encoded again by the contextual escaper.
 	Robots         bool
+	Deleted        bool
 	NameMask       string
 	ExternalIDMask string
+	EmailExact     string
 	FilterQuery    template.URL
 }
 
@@ -74,6 +76,7 @@ type UserRow struct {
 	Kind            string
 	Language        string
 	Guest           bool
+	Deleted         bool
 	FlaggedHighRate bool
 	CreatedAt       string
 	HasMoveStats    bool
@@ -150,19 +153,34 @@ type UserDetailView struct {
 	// MergedInto is the primary account id when this account has been retired by a
 	// merge, or empty for a live account.
 	MergedInto string
+	// The account-deletion dossier. Deleted marks a tombstoned account; DeletedAt and
+	// DeletedName are its deletion time and retained real name; LastLoginAt/IP are the
+	// last cold-load stamp (shown for any account); Retained is the credential journal.
+	Deleted     bool
+	DeletedAt   string
+	DeletedName string
+	LastLoginAt string
+	LastLoginIP string
+	Retained    []RetainedRow
 	// FlaggedHighRateAt is the pre-formatted soft high-rate marker timestamp,
 	// empty for an unflagged account; the card shows it with the Clear action.
 	FlaggedHighRateAt string
 	HintBalance       int
 	// HintGrantMax is the per-grant cap the operator's "add hints" form enforces (it mirrors the
 	// server's maxHintGrant), passed through so the policy value lives in one place.
-	HintGrantMax     int
-	CreatedAt        string
-	HasStats         bool
-	Stats            StatsRow
-	Identities       []IdentityRow
-	Games            []GameRow
+	HintGrantMax int
+	CreatedAt    string
+	HasStats     bool
+	Stats        StatsRow
+	Identities   []IdentityRow
+	// HasEmail gates the "Erase email" action; set when the account carries an email identity.
+	HasEmail bool
+	Games    []GameRow
+	// TelegramID and VKID are the account's platform external ids (empty when absent).
+	// TelegramID gates the "Send Telegram message" operator action; VKID surfaces the VK
+	// user id with a link to the VK profile (there is no VK messaging to drive).
 	TelegramID       string
+	VKID             string
 	ConnectorEnabled bool
 	// MoveChart is the pre-rendered inline SVG of the account's per-move-number think
 	// time (min/mean/max), empty when the account has no timed move.
@@ -230,6 +248,17 @@ type IdentityRow struct {
 	CreatedAt  string
 }
 
+// RetainedRow is one credential in the account-deletion retention journal (the legal
+// dossier of detached credentials): what was detached, when, and why.
+type RetainedRow struct {
+	Kind       string
+	ExternalID string
+	Reason     string
+	Confirmed  bool
+	LinkedAt   string
+	DetachedAt string
+}
+
 // GameRow is one game row in a list.
 type GameRow struct {
 	ID        string
@@ -469,15 +498,30 @@ type BannerCampaignRow struct {
 
 // BannerDetailView is the campaign detail/edit page. StartsAt/EndsAt are the
 // "YYYY-MM-DDTHH:MM" (UTC) values for the datetime-local inputs, empty when open.
+//
+// The colour-override and urgent fields drive the non-default campaign's editor:
+// OverrideAllOn/OverrideDarkOn report whether each colour set is active, and the
+// six *Bg/*Fg/*Link values seed the native colour inputs — the stored override
+// when a set is on, otherwise the neutral theme token so the picker starts from a
+// sensible colour and the live preview shows the real fallback.
 type BannerDetailView struct {
-	ID        string
-	Name      string
-	Weight    int
-	IsDefault bool
-	Enabled   bool
-	StartsAt  string
-	EndsAt    string
-	Messages  []BannerMessageRow
+	ID             string
+	Name           string
+	Weight         int
+	IsDefault      bool
+	Enabled        bool
+	StartsAt       string
+	EndsAt         string
+	Urgent         bool
+	OverrideAllOn  bool
+	AllBg          string
+	AllFg          string
+	AllLink        string
+	OverrideDarkOn bool
+	DarkBg         string
+	DarkFg         string
+	DarkLink       string
+	Messages       []BannerMessageRow
 }
 
 // BannerMessageRow is one bilingual message of a campaign. First/Last drive the

backend/internal/ads/ads.go

@@ -30,6 +30,15 @@ var ErrDefaultImmutable = errors.New("ads: the default campaign cannot be modifi
 // window or message body).
 var ErrValidation = errors.New("ads: validation")
 
+// ColorSet is an optional per-campaign colour override for the banner strip:
+// background, foreground (text) and link, each a "#rrggbb" hex string. The three
+// are set together or the whole set is absent (a nil *ColorSet).
+type ColorSet struct {
+	Bg   string
+	Fg   string
+	Link string
+}
+
 // Campaign is one advertising placement order with its messages.
 type Campaign struct {
 	ID        uuid.UUID // uuid.Nil on create
@@ -40,6 +49,16 @@ type Campaign struct {
 	StartsAt  *time.Time // nil = open-ended start; always nil for the default
 	EndsAt    *time.Time // nil = open-ended end; always nil for the default
 	Messages  []Message
+	// OverrideAll paints the strip on every theme; OverrideDark, when set, further
+	// overrides the dark theme (the client resolves dark ← dark ?? all ?? token,
+	// light ← all ?? token). Both are nil for the default campaign and for a
+	// campaign that keeps the neutral theme tokens. Non-default only.
+	OverrideAll  *ColorSet
+	OverrideDark *ColorSet
+	// Urgent forces the banner on every viewer (bypassing eligibility) and, while
+	// any urgent campaign is active, suppresses every non-urgent campaign and the
+	// default remainder. Non-default only; always false for the default campaign.
+	Urgent    bool
 	CreatedAt time.Time
 	UpdatedAt time.Time
 }
@@ -70,29 +89,32 @@ type Timings struct {
 
 // ActiveCampaign is one campaign in the resolved rotation feed sent to a client:
 // its GCD-reduced show weight and its messages, already resolved to the viewer's
-// language and in display (round-robin) order.
+// language and in display (round-robin) order, plus the optional colour overrides
+// the client applies to the strip (nil = the neutral theme tokens). Urgency is not
+// carried here: it is resolved server-side into the set's membership and the
+// eligibility bypass, so the client only ever renders what it is sent.
 type ActiveCampaign struct {
-	Weight   int
-	Messages []string
-}
-
-// Eligible reports whether an account should be shown the advertising banner: a
-// free account (not paid) with an empty hint wallet and without the no_banner
-// role. The no_banner role suppresses the banner unconditionally; buying a paid
-// account or any hints also removes it.
-func Eligible(paidAccount bool, hintBalance int, hasNoBanner bool) bool {
-	return !paidAccount && hintBalance <= 0 && !hasNoBanner
+	Weight       int
+	Messages     []string
+	OverrideAll  *ColorSet
+	OverrideDark *ColorSet
 }
 
 // computeActiveSet builds the resolved rotation feed from the enabled campaigns
-// at time now, in language lang. Campaigns outside their validity window, and
-// campaigns with no messages, are dropped. The default campaign's effective
-// weight is the remainder up to 100% — max(0, 100 - sum of active timed
-// weights) — so it fills unsold inventory and is dropped entirely when timed
-// campaigns already reach 100%. Weights are then reduced by their GCD so the
-// fair rotation cycle stays short. The input is expected to be the enabled
-// campaigns (ActiveCampaigns); disabled ones must already be excluded.
-func computeActiveSet(campaigns []Campaign, now time.Time, lang string) []ActiveCampaign {
+// at time now, in language lang, and reports whether the feed is an urgent one.
+// Campaigns outside their validity window, and campaigns with no messages, are
+// dropped.
+//
+// While any active campaign is urgent, the feed is the urgent campaigns alone —
+// every non-urgent timed campaign and the default remainder are suppressed for
+// the duration (and the caller shows the feed to every viewer, bypassing
+// eligibility). Otherwise the default campaign's effective weight is the
+// remainder up to 100% — max(0, 100 - sum of active timed weights) — so it fills
+// unsold inventory and is dropped entirely when timed campaigns already reach
+// 100%. Weights are then reduced by their GCD so the fair rotation cycle stays
+// short. The input is expected to be the enabled campaigns (ActiveCampaigns);
+// disabled ones must already be excluded.
+func computeActiveSet(campaigns []Campaign, now time.Time, lang string) ([]ActiveCampaign, bool) {
 	var timed []Campaign
 	var def *Campaign
 	for i := range campaigns {
@@ -108,20 +130,54 @@ func computeActiveSet(campaigns []Campaign, now time.Time, lang string) []Active
 			timed = append(timed, c)
 		}
 	}
+	if urgent := filterUrgent(timed); len(urgent) > 0 {
+		out := make([]ActiveCampaign, 0, len(urgent))
+		for _, c := range urgent {
+			out = append(out, activeFrom(c, lang))
+		}
+		reduceByGCD(out)
+		return out, true
+	}
 	sumTimed := 0
 	for _, c := range timed {
 		sumTimed += c.Weight
 	}
 	out := make([]ActiveCampaign, 0, len(timed)+1)
 	for _, c := range timed {
-		out = append(out, ActiveCampaign{Weight: c.Weight, Messages: resolveBodies(c.Messages, lang)})
+		out = append(out, activeFrom(c, lang))
 	}
 	if def != nil {
 		if dw := 100 - sumTimed; dw > 0 {
-			out = append(out, ActiveCampaign{Weight: dw, Messages: resolveBodies(def.Messages, lang)})
+			a := activeFrom(*def, lang)
+			a.Weight = dw // the default's stored weight is nominal; it fills the remainder
+			out = append(out, a)
 		}
 	}
 	reduceByGCD(out)
+	return out, false
+}
+
+// activeFrom projects a campaign to its rotation-feed entry: its show weight, its
+// language-resolved messages and its colour overrides (carried through by
+// reference, they are read-only).
+func activeFrom(c Campaign, lang string) ActiveCampaign {
+	return ActiveCampaign{
+		Weight:       c.Weight,
+		Messages:     resolveBodies(c.Messages, lang),
+		OverrideAll:  c.OverrideAll,
+		OverrideDark: c.OverrideDark,
+	}
+}
+
+// filterUrgent returns the urgent campaigns among cs, preserving order. It is the
+// preempt selector: a non-empty result makes the whole feed urgent.
+func filterUrgent(cs []Campaign) []Campaign {
+	var out []Campaign
+	for _, c := range cs {
+		if c.Urgent {
+			out = append(out, c)
+		}
+	}
 	return out
 }
 

backend/internal/ads/ads_test.go

@@ -6,30 +6,6 @@ import (
 	"time"
 )
 
-func TestEligible(t *testing.T) {
-	tests := []struct {
-		name        string
-		paidAccount bool
-		hintBalance int
-		hasNoBanner bool
-		want        bool
-	}{
-		{name: "free, empty wallet, no role", want: true},
-		{name: "paid", paidAccount: true, want: false},
-		{name: "has hints", hintBalance: 3, want: false},
-		{name: "no_banner role", hasNoBanner: true, want: false},
-		{name: "paid and has hints", paidAccount: true, hintBalance: 5, want: false},
-		{name: "no_banner overrides everything", hasNoBanner: true, want: false},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := Eligible(tt.paidAccount, tt.hintBalance, tt.hasNoBanner); got != tt.want {
-				t.Errorf("Eligible(%v,%d,%v) = %v, want %v", tt.paidAccount, tt.hintBalance, tt.hasNoBanner, got, tt.want)
-			}
-		})
-	}
-}
-
 func TestComputeActiveSet(t *testing.T) {
 	now := time.Date(2026, 6, 15, 12, 0, 0, 0, time.UTC)
 	past := now.Add(-24 * time.Hour)
@@ -46,12 +22,19 @@ func TestComputeActiveSet(t *testing.T) {
 	timed := func(name string, weight int, starts, ends *time.Time, msgs []Message) Campaign {
 		return Campaign{Name: name, Weight: weight, Enabled: true, StartsAt: starts, EndsAt: ends, Messages: msgs}
 	}
+	urgent := func(name string, weight int, msgs []Message) Campaign {
+		c := timed(name, weight, nil, nil, msgs)
+		c.Urgent = true
+		return c
+	}
+	red := &ColorSet{Bg: "#aa0000", Fg: "#ffffff", Link: "#ffdd00"}
 
 	tests := []struct {
-		name      string
-		campaigns []Campaign
-		lang      string
-		want      []ActiveCampaign
+		name       string
+		campaigns  []Campaign
+		lang       string
+		want       []ActiveCampaign
+		wantUrgent bool
 	}{
 		{
 			name:      "default only reduces to weight 1",
@@ -152,22 +135,71 @@ func TestComputeActiveSet(t *testing.T) {
 			lang: "en",
 			want: []ActiveCampaign{{Weight: 1, Messages: []string{"one-en", "two-en"}}},
 		},
+		{
+			name: "urgent preempts default and normal timed",
+			campaigns: []Campaign{
+				def(msg("house")),
+				timed("promo", 40, nil, nil, msg("promo")),
+				urgent("alert", 50, msg("alert")),
+			},
+			lang: "en",
+			// only the urgent campaign survives; a lone weight reduces to 1.
+			want:       []ActiveCampaign{{Weight: 1, Messages: []string{"alert-en"}}},
+			wantUrgent: true,
+		},
+		{
+			name: "multiple urgent share the feed by gcd",
+			campaigns: []Campaign{
+				def(msg("house")),
+				urgent("a", 60, msg("a")),
+				urgent("b", 40, msg("b")),
+			},
+			lang: "en",
+			// default and any non-urgent dropped; gcd(60,40)=20 -> 3 and 2.
+			want: []ActiveCampaign{
+				{Weight: 3, Messages: []string{"a-en"}},
+				{Weight: 2, Messages: []string{"b-en"}},
+			},
+			wantUrgent: true,
+		},
+		{
+			name: "out-of-window urgent does not preempt",
+			campaigns: []Campaign{
+				def(msg("house")),
+				func() Campaign { c := urgent("future", 50, msg("future")); c.StartsAt = &future; return c }(),
+			},
+			lang: "en",
+			// the urgent campaign is not yet live, so the normal default feed stands.
+			want: []ActiveCampaign{{Weight: 1, Messages: []string{"house-en"}}},
+		},
+		{
+			name: "colour overrides ride the active campaign",
+			campaigns: []Campaign{
+				def(msg("house")),
+				func() Campaign { c := timed("promo", 100, nil, nil, msg("promo")); c.OverrideAll = red; return c }(),
+			},
+			lang: "en",
+			want: []ActiveCampaign{{Weight: 1, Messages: []string{"promo-en"}, OverrideAll: red}},
+		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got := computeActiveSet(tt.campaigns, now, tt.lang)
+			got, gotUrgent := computeActiveSet(tt.campaigns, now, tt.lang)
 			if !reflect.DeepEqual(got, tt.want) {
 				t.Errorf("computeActiveSet() =\n  %#v\nwant\n  %#v", got, tt.want)
 			}
+			if gotUrgent != tt.wantUrgent {
+				t.Errorf("computeActiveSet() urgent = %v, want %v", gotUrgent, tt.wantUrgent)
+			}
 		})
 	}
 }
 
 func TestComputeActiveSetEmpty(t *testing.T) {
 	// No campaigns at all yields an empty (non-nil-or-nil) feed without panicking.
-	if got := computeActiveSet(nil, time.Now(), "en"); len(got) != 0 {
-		t.Errorf("computeActiveSet(nil) = %#v, want empty", got)
+	if got, urgent := computeActiveSet(nil, time.Now(), "en"); len(got) != 0 || urgent {
+		t.Errorf("computeActiveSet(nil) = %#v urgent=%v, want empty non-urgent", got, urgent)
 	}
 }
 

backend/internal/ads/service.go

@@ -3,6 +3,7 @@ package ads
 import (
 	"context"
 	"fmt"
+	"regexp"
 	"strings"
 	"time"
 
@@ -40,17 +41,20 @@ func NewService(store *Store) *Service { return &Service{store: store} }
 // ActiveSet returns the resolved rotation feed for a viewer in language lang
 // (en/ru) together with the global display timings: the currently-active
 // campaigns, each with its GCD-reduced show weight and its messages resolved to
-// lang, ready for the client's weighted round-robin.
-func (s *Service) ActiveSet(ctx context.Context, lang string) ([]ActiveCampaign, Timings, error) {
+// lang, ready for the client's weighted round-robin. The bool result reports
+// whether the feed is urgent — an urgent feed is shown to every viewer
+// regardless of eligibility (the caller skips the eligibility gate for it).
+func (s *Service) ActiveSet(ctx context.Context, lang string) ([]ActiveCampaign, Timings, bool, error) {
 	campaigns, err := s.store.ActiveCampaigns(ctx)
 	if err != nil {
-		return nil, Timings{}, err
+		return nil, Timings{}, false, err
 	}
 	timings, err := s.store.Settings(ctx)
 	if err != nil {
-		return nil, Timings{}, err
+		return nil, Timings{}, false, err
 	}
-	return computeActiveSet(campaigns, time.Now().UTC(), lang), timings, nil
+	set, urgent := computeActiveSet(campaigns, time.Now().UTC(), lang)
+	return set, timings, urgent, nil
 }
 
 // ListCampaigns returns every campaign with its messages, for the admin console.
@@ -76,8 +80,13 @@ func (s *Service) CreateCampaign(ctx context.Context, c Campaign) (uuid.UUID, er
 	if err := validWindow(c.StartsAt, c.EndsAt); err != nil {
 		return uuid.Nil, err
 	}
+	all, dark, err := validOverrides(c.OverrideAll, c.OverrideDark)
+	if err != nil {
+		return uuid.Nil, err
+	}
 	return s.store.CreateCampaign(ctx, Campaign{
 		Name: name, Weight: c.Weight, Enabled: c.Enabled, StartsAt: c.StartsAt, EndsAt: c.EndsAt,
+		OverrideAll: all, OverrideDark: dark, Urgent: c.Urgent,
 	})
 }
 
@@ -99,6 +108,7 @@ func (s *Service) UpdateCampaign(ctx context.Context, c Campaign) error {
 		upd.Enabled = true
 		upd.StartsAt = nil
 		upd.EndsAt = nil
+		// The default (house) campaign stays plain: no colour overrides, never urgent.
 	} else {
 		if err := validWeight(c.Weight); err != nil {
 			return err
@@ -106,10 +116,17 @@ func (s *Service) UpdateCampaign(ctx context.Context, c Campaign) error {
 		if err := validWindow(c.StartsAt, c.EndsAt); err != nil {
 			return err
 		}
+		all, dark, err := validOverrides(c.OverrideAll, c.OverrideDark)
+		if err != nil {
+			return err
+		}
 		upd.Weight = c.Weight
 		upd.Enabled = c.Enabled
 		upd.StartsAt = c.StartsAt
 		upd.EndsAt = c.EndsAt
+		upd.OverrideAll = all
+		upd.OverrideDark = dark
+		upd.Urgent = c.Urgent
 	}
 	return s.store.UpdateCampaign(ctx, upd)
 }
@@ -254,6 +271,46 @@ func validWindow(starts, ends *time.Time) error {
 	return nil
 }
 
+// hexColor matches a "#rrggbb" colour — the format the console's native colour
+// input emits and the wire carries.
+var hexColor = regexp.MustCompile(`^#[0-9a-fA-F]{6}$`)
+
+// validOverrides validates the two optional colour sets together and returns
+// their normalised copies (nil when a set is absent), so a caller can store them
+// directly.
+func validOverrides(all, dark *ColorSet) (*ColorSet, *ColorSet, error) {
+	va, err := validColorSet(all)
+	if err != nil {
+		return nil, nil, err
+	}
+	vd, err := validColorSet(dark)
+	if err != nil {
+		return nil, nil, err
+	}
+	return va, vd, nil
+}
+
+// validColorSet validates one optional colour override: a nil set passes (no
+// override); otherwise all three colours must be present and "#rrggbb". It
+// returns a trimmed, lower-cased copy.
+func validColorSet(cs *ColorSet) (*ColorSet, error) {
+	if cs == nil {
+		return nil, nil
+	}
+	bg := strings.TrimSpace(cs.Bg)
+	fg := strings.TrimSpace(cs.Fg)
+	link := strings.TrimSpace(cs.Link)
+	if bg == "" || fg == "" || link == "" {
+		return nil, fmt.Errorf("%w: a colour override needs all of background, text and link", ErrValidation)
+	}
+	for _, h := range []string{bg, fg, link} {
+		if !hexColor.MatchString(h) {
+			return nil, fmt.Errorf("%w: colours must be #rrggbb hex", ErrValidation)
+		}
+	}
+	return &ColorSet{Bg: strings.ToLower(bg), Fg: strings.ToLower(fg), Link: strings.ToLower(link)}, nil
+}
+
 // validBodies trims and bounds both mandatory language bodies of a message.
 func validBodies(bodyEn, bodyRu string) (string, string, error) {
 	en := strings.TrimSpace(bodyEn)

backend/internal/ads/store.go

@@ -90,15 +90,23 @@ func (s *Store) Campaign(ctx context.Context, id uuid.UUID) (Campaign, error) {
 func (s *Store) CreateCampaign(ctx context.Context, c Campaign) (uuid.UUID, error) {
 	id := uuid.New()
 	now := time.Now().UTC()
+	abg, afg, alink := colorCols(c.OverrideAll)
+	dbg, dfg, dlink := colorCols(c.OverrideDark)
 	stmt := table.AdCampaigns.INSERT(
 		table.AdCampaigns.CampaignID, table.AdCampaigns.Name, table.AdCampaigns.Weight,
 		table.AdCampaigns.IsDefault, table.AdCampaigns.Enabled,
 		table.AdCampaigns.StartsAt, table.AdCampaigns.EndsAt,
+		table.AdCampaigns.OverrideBg, table.AdCampaigns.OverrideFg, table.AdCampaigns.OverrideLink,
+		table.AdCampaigns.OverrideBgDark, table.AdCampaigns.OverrideFgDark, table.AdCampaigns.OverrideLinkDark,
+		table.AdCampaigns.Urgent,
 		table.AdCampaigns.CreatedAt, table.AdCampaigns.UpdatedAt,
 	).VALUES(
 		postgres.UUID(id), postgres.String(c.Name), postgres.Int(int64(c.Weight)),
 		postgres.Bool(false), postgres.Bool(c.Enabled),
 		tsOrNull(c.StartsAt), tsOrNull(c.EndsAt),
+		abg, afg, alink,
+		dbg, dfg, dlink,
+		postgres.Bool(c.Urgent),
 		postgres.TimestampzT(now), postgres.TimestampzT(now),
 	)
 	if _, err := stmt.ExecContext(ctx, s.db); err != nil {
@@ -111,12 +119,20 @@ func (s *Store) CreateCampaign(ctx context.Context, c Campaign) (uuid.UUID, erro
 // window. The default flag is never touched here. Returns ErrNotFound when no
 // campaign matches.
 func (s *Store) UpdateCampaign(ctx context.Context, c Campaign) error {
+	abg, afg, alink := colorCols(c.OverrideAll)
+	dbg, dfg, dlink := colorCols(c.OverrideDark)
 	stmt := table.AdCampaigns.UPDATE(
 		table.AdCampaigns.Name, table.AdCampaigns.Weight, table.AdCampaigns.Enabled,
-		table.AdCampaigns.StartsAt, table.AdCampaigns.EndsAt, table.AdCampaigns.UpdatedAt,
+		table.AdCampaigns.StartsAt, table.AdCampaigns.EndsAt,
+		table.AdCampaigns.OverrideBg, table.AdCampaigns.OverrideFg, table.AdCampaigns.OverrideLink,
+		table.AdCampaigns.OverrideBgDark, table.AdCampaigns.OverrideFgDark, table.AdCampaigns.OverrideLinkDark,
+		table.AdCampaigns.Urgent, table.AdCampaigns.UpdatedAt,
 	).SET(
 		postgres.String(c.Name), postgres.Int(int64(c.Weight)), postgres.Bool(c.Enabled),
-		tsOrNull(c.StartsAt), tsOrNull(c.EndsAt), postgres.TimestampzT(time.Now().UTC()),
+		tsOrNull(c.StartsAt), tsOrNull(c.EndsAt),
+		abg, afg, alink,
+		dbg, dfg, dlink,
+		postgres.Bool(c.Urgent), postgres.TimestampzT(time.Now().UTC()),
 	).WHERE(table.AdCampaigns.CampaignID.EQ(postgres.UUID(c.ID)))
 	return execOne(ctx, s.db, stmt, "update campaign")
 }
@@ -257,18 +273,40 @@ func execOne(ctx context.Context, db qrm.Executable, stmt postgres.Statement, wh
 
 func modelToCampaign(r model.AdCampaigns) Campaign {
 	return Campaign{
-		ID:        r.CampaignID,
-		Name:      r.Name,
-		Weight:    int(r.Weight),
-		IsDefault: r.IsDefault,
-		Enabled:   r.Enabled,
-		StartsAt:  r.StartsAt,
-		EndsAt:    r.EndsAt,
-		CreatedAt: r.CreatedAt,
-		UpdatedAt: r.UpdatedAt,
+		ID:           r.CampaignID,
+		Name:         r.Name,
+		Weight:       int(r.Weight),
+		IsDefault:    r.IsDefault,
+		Enabled:      r.Enabled,
+		StartsAt:     r.StartsAt,
+		EndsAt:       r.EndsAt,
+		OverrideAll:  colorSetFrom(r.OverrideBg, r.OverrideFg, r.OverrideLink),
+		OverrideDark: colorSetFrom(r.OverrideBgDark, r.OverrideFgDark, r.OverrideLinkDark),
+		Urgent:       r.Urgent,
+		CreatedAt:    r.CreatedAt,
+		UpdatedAt:    r.UpdatedAt,
 	}
 }
 
+// colorSetFrom rebuilds an optional ColorSet from three nullable colour columns.
+// The all-or-nothing CHECK keeps the trio consistent, so a nil in any one means
+// the set is absent.
+func colorSetFrom(bg, fg, link *string) *ColorSet {
+	if bg == nil || fg == nil || link == nil {
+		return nil
+	}
+	return &ColorSet{Bg: *bg, Fg: *fg, Link: *link}
+}
+
+// colorCols renders a *ColorSet as its three column value-expressions in
+// bg, fg, link order — NULL for each when the set is absent.
+func colorCols(cs *ColorSet) (bg, fg, link postgres.Expression) {
+	if cs == nil {
+		return postgres.NULL, postgres.NULL, postgres.NULL
+	}
+	return postgres.String(cs.Bg), postgres.String(cs.Fg), postgres.String(cs.Link)
+}
+
 func modelToMessage(r model.AdMessages) Message {
 	return Message{
 		ID:         r.MessageID,

backend/internal/config/config.go

@@ -4,6 +4,7 @@ package config
 
 import (
 	"fmt"
+	"net/url"
 	"os"
 	"strconv"
 	"time"
@@ -42,6 +43,12 @@ type Config struct {
 	// SMTP configures the email relay used for confirm-codes. An empty Host
 	// selects the development log mailer (the code is logged, not sent).
 	SMTP account.SMTPConfig
+	// PublicBaseURL is the canonical public origin (scheme + host, e.g.
+	// https://erudit-game.ru) used to build absolute links in outgoing email — the
+	// confirm deeplink and the footer landing link. It is deliberately not derived
+	// from a request Host header, which would let an attacker inject a phishing link
+	// into the email. Required whenever an SMTP relay is configured.
+	PublicBaseURL string
 	// ConnectorAddr is the gRPC address of the Telegram platform connector
 	// side-service, used by the admin console to send operator broadcasts. Empty
 	// disables broadcasts (the admin broadcast actions report "not configured").
@@ -51,6 +58,12 @@ type Config struct {
 	// GuestRetention is the account age past which an unused guest (no game seat)
 	// is eligible for deletion by the reaper.
 	GuestRetention time.Duration
+	// ExportSignKey signs the finished-game export download URLs. Empty leaves
+	// the export-URL endpoints disabled (503 on mint, 404 on download).
+	ExportSignKey string
+	// RendererURL is the base URL of the internal image-render sidecar (e.g.
+	// http://renderer:8090). Empty disables the PNG export artifact.
+	RendererURL string
 }
 
 // Defaults applied when the corresponding environment variable is unset.
@@ -130,11 +143,14 @@ func Load() (Config, error) {
 	}
 
 	smtp := account.SMTPConfig{
-		Host:     os.Getenv("BACKEND_SMTP_HOST"),
-		Port:     envOr("BACKEND_SMTP_PORT", "587"),
-		Username: os.Getenv("BACKEND_SMTP_USERNAME"),
-		Password: os.Getenv("BACKEND_SMTP_PASSWORD"),
-		From:     envOr("BACKEND_SMTP_FROM", "no-reply@localhost"),
+		Host:      os.Getenv("BACKEND_SMTP_HOST"),
+		Port:      envOr("BACKEND_SMTP_PORT", "587"),
+		Username:  os.Getenv("BACKEND_SMTP_USERNAME"),
+		Password:  os.Getenv("BACKEND_SMTP_PASSWORD"),
+		From:      envOr("BACKEND_SMTP_FROM", "no-reply@localhost"),
+		TLS:       os.Getenv("BACKEND_SMTP_TLS"),
+		AdminFrom: os.Getenv("BACKEND_SMTP_ADMIN_FROM"),
+		AdminTo:   os.Getenv("BACKEND_ADMIN_EMAIL"),
 	}
 
 	c := Config{
@@ -148,9 +164,12 @@ func Load() (Config, error) {
 		Robot:             rb,
 		RateWatch:         rw,
 		SMTP:              smtp,
+		PublicBaseURL:     os.Getenv("BACKEND_PUBLIC_BASE_URL"),
 		ConnectorAddr:     os.Getenv("BACKEND_CONNECTOR_ADDR"),
 		GuestReapInterval: guestReapInterval,
 		GuestRetention:    guestRetention,
+		ExportSignKey:     os.Getenv("BACKEND_EXPORT_SIGN_KEY"),
+		RendererURL:       os.Getenv("BACKEND_RENDERER_URL"),
 	}
 	if err := c.validate(); err != nil {
 		return Config{}, err
@@ -195,6 +214,14 @@ func (c Config) validate() error {
 	if c.GuestRetention <= 0 {
 		return fmt.Errorf("config: BACKEND_GUEST_RETENTION must be positive")
 	}
+	if c.SMTP.Host != "" {
+		if c.PublicBaseURL == "" {
+			return fmt.Errorf("config: BACKEND_PUBLIC_BASE_URL must be set when BACKEND_SMTP_HOST is configured")
+		}
+		if u, err := url.Parse(c.PublicBaseURL); err != nil || u.Scheme == "" || u.Host == "" {
+			return fmt.Errorf("config: BACKEND_PUBLIC_BASE_URL %q must be an absolute URL (scheme://host)", c.PublicBaseURL)
+		}
+	}
 	return nil
 }
 

backend/internal/engine/endfixture_test.go

@@ -0,0 +1,123 @@
+package engine
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gitea.iliadenisov.ru/developer/scrabble-solver/rules"
+)
+
+// The offline engine (ui/src/lib/localgame) reproduces the end-of-game rack settlement and the
+// winner rule so a local game finishes with the same scores as the server. These golden fixtures
+// pin the ported pure functions (applyEndAdjustment / winner / rackValue) to the real Go engine.
+// Being in-package, this emitter constructs Game values directly and drives the unexported
+// end-game math on chosen positions.
+
+type endCaseIn struct {
+	Name     string  `json:"name"`
+	Variant  string  `json:"variant"`
+	Reason   string  `json:"reason"`
+	Hands    [][]int `json:"hands"`
+	Scores   []int   `json:"scores"`
+	Resigned []bool  `json:"resigned"`
+	ToMove   int     `json:"toMove"`
+}
+
+type endCaseOut struct {
+	endCaseIn
+	ScoresAfter []int `json:"scoresAfter"`
+	Winner      int   `json:"winner"`
+}
+
+func rulesetFor(variant string) *rules.Ruleset {
+	switch variant {
+	case "scrabble_ru":
+		return rules.RussianScrabble()
+	case "erudit_ru":
+		return rules.Erudit()
+	default:
+		return rules.English()
+	}
+}
+
+func reasonFor(s string) EndReason {
+	switch s {
+	case "out_of_tiles":
+		return EndOutOfTiles
+	case "scoreless":
+		return EndScoreless
+	case "resign":
+		return EndResign
+	case "aborted":
+		return EndAborted
+	}
+	return EndNotOver
+}
+
+func handsBytes(hands [][]int) [][]byte {
+	out := make([][]byte, len(hands))
+	for i, h := range hands {
+		b := make([]byte, len(h))
+		for j, x := range h {
+			b[j] = byte(x)
+		}
+		out[i] = b
+	}
+	return out
+}
+
+// TestEmitEndgameFixtures regenerates ui/src/lib/localgame/testdata/endgame.json. Gated by
+// EMIT_ENGINE_FIXTURES. Regenerate with:
+//
+//	EMIT_ENGINE_FIXTURES=1 go test ./backend/internal/engine -run TestEmitEndgameFixtures
+func TestEmitEndgameFixtures(t *testing.T) {
+	if os.Getenv("EMIT_ENGINE_FIXTURES") == "" {
+		t.Skip("set EMIT_ENGINE_FIXTURES=1 to regenerate ui/src/lib/localgame/testdata/endgame.json")
+	}
+
+	cases := []endCaseIn{
+		{"out-basic", "scrabble_en", "out_of_tiles", [][]int{{}, {0, 1, 2}}, []int{50, 40}, []bool{false, false}, 0},
+		{"out-blank", "scrabble_en", "out_of_tiles", [][]int{{}, {255, 0}}, []int{30, 30}, []bool{false, false}, 0},
+		{"out-erudit-yo", "erudit_ru", "out_of_tiles", [][]int{{}, {6, 32}}, []int{10, 10}, []bool{false, false}, 0},
+		{"out-tie", "scrabble_en", "out_of_tiles", [][]int{{}, {}}, []int{30, 30}, []bool{false, false}, 0},
+		{"out-3p", "scrabble_ru", "out_of_tiles", [][]int{{}, {0, 1}, {2}}, []int{10, 10, 10}, []bool{false, false, false}, 0},
+		{"scoreless", "scrabble_en", "scoreless", [][]int{{0, 1}, {2, 3}}, []int{20, 20}, []bool{false, false}, 0},
+		{"resign-2p", "scrabble_en", "resign", [][]int{{}, {0}}, []int{100, 10}, []bool{true, false}, 1},
+		{"resign-3p", "scrabble_en", "resign", [][]int{{}, {}, {}}, []int{50, 60, 40}, []bool{false, true, false}, 0},
+		{"aborted", "scrabble_en", "aborted", [][]int{{0}, {1}}, []int{40, 30}, []bool{false, false}, 0},
+	}
+
+	out := make([]endCaseOut, 0, len(cases))
+	for _, c := range cases {
+		rs := rulesetFor(c.Variant)
+		scores := append([]int(nil), c.Scores...)
+		g := &Game{
+			rules:    rs,
+			hands:    handsBytes(c.Hands),
+			scores:   scores,
+			resigned: c.Resigned,
+			toMove:   c.ToMove,
+		}
+		reason := reasonFor(c.Reason)
+		g.over = true
+		g.reason = reason
+		g.applyEndAdjustment(reason)
+		out = append(out, endCaseOut{endCaseIn: c, ScoresAfter: g.scores, Winner: g.winner()})
+	}
+
+	dir := filepath.Join("..", "..", "..", "ui", "src", "lib", "localgame", "testdata")
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		t.Fatalf("mkdir %s: %v", dir, err)
+	}
+	data, err := json.MarshalIndent(map[string]any{"cases": out}, "", "  ")
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+	path := filepath.Join(dir, "endgame.json")
+	if err := os.WriteFile(path, append(data, '\n'), 0o644); err != nil {
+		t.Fatalf("write %s: %v", path, err)
+	}
+	t.Logf("wrote %s (%d cases)", path, len(out))
+}

backend/internal/engine/registry.go

@@ -21,11 +21,13 @@ var dictFiles = map[Variant]string{
 	VariantErudit:          "ru_erudit.dawg",
 }
 
-// entry is one resident dictionary: the loaded finder and the solver built over
-// it. The finder is retained so Close can release it.
+// entry is one resident dictionary: the loaded finder, the solver built over it
+// and the file it was loaded from. The finder is retained so Close can release
+// it; path is retained so the raw bytes can be re-read for the client download.
 type entry struct {
 	finder dawg.Finder
 	solver *scrabble.Solver
+	path   string
 }
 
 // Registry holds the dictionaries resident in memory, addressed by variant and
@@ -130,7 +132,7 @@ func (r *Registry) Load(v Variant, version, dir string) error {
 	if old, ok := r.entries[v][version]; ok {
 		_ = old.finder.Close()
 	}
-	r.entries[v][version] = entry{finder: finder, solver: scrabble.NewSolver(rs, finder)}
+	r.entries[v][version] = entry{finder: finder, solver: scrabble.NewSolver(rs, finder), path: path}
 	r.latest[v] = version
 	return nil
 }
@@ -202,6 +204,30 @@ func (r *Registry) Versions(v Variant) []string {
 	return versions
 }
 
+// DictBytes returns the raw serialized DAWG for the (variant, version) pair,
+// re-read from the file it was loaded from — the same immutable bytes the solver
+// holds. It backs the client-side dictionary download for the local move
+// preview. It returns ErrUnknownVariant or ErrUnknownVersion when that dictionary
+// is not resident, and wraps any read error. The file is read outside the lock.
+func (r *Registry) DictBytes(v Variant, version string) ([]byte, error) {
+	r.mu.RLock()
+	versions, ok := r.entries[v]
+	if !ok {
+		r.mu.RUnlock()
+		return nil, fmt.Errorf("%w: %s", ErrUnknownVariant, v)
+	}
+	e, ok := versions[version]
+	r.mu.RUnlock()
+	if !ok {
+		return nil, fmt.Errorf("%w: %s/%s", ErrUnknownVersion, v, version)
+	}
+	data, err := os.ReadFile(e.path)
+	if err != nil {
+		return nil, fmt.Errorf("engine: read %s/%s dictionary bytes from %s: %w", v, version, e.path, err)
+	}
+	return data, nil
+}
+
 // Lookup reports whether word is present in the (variant, version) dictionary,
 // backing the unlimited word-check tool. It returns ErrUnknownVariant or
 // ErrUnknownVersion when that dictionary is not resident, and an error when word

backend/internal/feedback/service.go

@@ -195,6 +195,11 @@ func (svc *Service) CountUnread(ctx context.Context) (int, error) {
 	return svc.store.CountUnread(ctx)
 }
 
+// CountSince counts feedback created after since, for the operator alert worker.
+func (svc *Service) CountSince(ctx context.Context, since time.Time) (int, error) {
+	return svc.store.CountSince(ctx, since)
+}
+
 // Attachment returns a message's file name and bytes, reporting false when absent.
 func (svc *Service) Attachment(ctx context.Context, id uuid.UUID) (string, []byte, bool, error) {
 	return svc.store.Attachment(ctx, id)

backend/internal/feedback/store.go

@@ -386,3 +386,15 @@ func (s *Store) CountUnread(ctx context.Context) (int, error) {
 	}
 	return n, nil
 }
+
+// CountSince counts feedback messages created strictly after since — the operator alert
+// worker's "new since the last check" signal.
+func (s *Store) CountSince(ctx context.Context, since time.Time) (int, error) {
+	var n int
+	if err := s.db.QueryRowContext(ctx,
+		`SELECT COUNT(*) FROM backend.feedback_messages WHERE created_at > $1`, since,
+	).Scan(&n); err != nil {
+		return 0, fmt.Errorf("feedback: count since: %w", err)
+	}
+	return n, nil
+}

backend/internal/game/helpers_test.go

@@ -69,6 +69,29 @@ func TestHintsRemaining(t *testing.T) {
 	}
 }
 
+func TestHintUnlockLeftSeconds(t *testing.T) {
+	now := time.Now()
+	// A gated vs_ai game on the caller's turn, the robot having moved 10 min ago (turn started then).
+	gated := Game{VsAI: true, ToMove: 0, MoveCount: 2, TurnStartedAt: now.Add(-10 * time.Minute)}
+	cases := []struct {
+		name string
+		g    Game
+		seat int
+		want int
+	}{
+		{"non-vs_ai is open", Game{VsAI: false, ToMove: 0, MoveCount: 2, TurnStartedAt: now.Add(-10 * time.Minute)}, 0, 0},
+		{"not the caller's turn is open", gated, 1, 0},
+		{"human first move (no robot move) is open", Game{VsAI: true, ToMove: 0, MoveCount: 0, TurnStartedAt: now}, 0, 0},
+		{"robot moved 10 min ago leaves 20 min", gated, 0, 20 * 60},
+		{"robot moved past the window is open", Game{VsAI: true, ToMove: 0, MoveCount: 2, TurnStartedAt: now.Add(-40 * time.Minute)}, 0, 0},
+	}
+	for _, c := range cases {
+		if got := hintUnlockLeftSeconds(c.g, c.seat, now); got != c.want {
+			t.Errorf("%s: hintUnlockLeftSeconds = %d, want %d", c.name, got, c.want)
+		}
+	}
+}
+
 func TestAllowedTimeout(t *testing.T) {
 	if !allowedTimeout(24 * time.Hour) {
 		t.Error("24h must be allowed")

backend/internal/game/service.go

@@ -18,6 +18,8 @@ import (
 	"scrabble/backend/internal/account"
 	"scrabble/backend/internal/engine"
 	"scrabble/backend/internal/notify"
+	"scrabble/backend/internal/payments"
+	"scrabble/backend/internal/session"
 )
 
 // Service is the game domain: it drives the engine over a single match, persists
@@ -50,12 +52,23 @@ type Service struct {
 	// its asynchronous TriggerMove); nil disables the fast path (the scan still covers
 	// these games). Kept as a func so the game package never imports the robot package.
 	aiTrigger func(gameID uuid.UUID)
+	// hintWallet is the payments surface the online-game hint path spends against (the
+	// segmented, context-aware hint balance). It is set by SetHintWallet during wiring; when
+	// nil, only the free per-game allowance is served (no purchased hints). vs_ai hints are
+	// wallet-free and never touch it.
+	hintWallet HintWallet
 	// clearNudges, when set, marks the actor's pending nudges in a game read once they
 	// have committed a move (a nudge answered by moving stops counting as unread). It is
 	// best-effort and kept as a func so the game package never imports the social package.
 	clearNudges func(ctx context.Context, gameID, accountID uuid.UUID) error
-	metrics     *gameMetrics
-	log         *zap.Logger
+	// expireNudges, when set, marks every pending nudge in a game read once the game
+	// finishes (the nudge badge is stale on a completed game). Unlike clearNudges it is
+	// keyed by game alone — it clears all seats' nudges, not one mover's — and runs on
+	// every completion path through commit. Best-effort; a func so the game package never
+	// imports the social package.
+	expireNudges func(ctx context.Context, gameID uuid.UUID) error
+	metrics      *gameMetrics
+	log          *zap.Logger
 }
 
 // NewService constructs a Service. store and accounts wrap the same pool;
@@ -99,6 +112,39 @@ func (svc *Service) SetAITrigger(trigger func(gameID uuid.UUID)) {
 	svc.aiTrigger = trigger
 }
 
+// HintWallet is the payments surface the online-game hint path uses: the context-aware hint
+// balance (HintsAvailable) and a one-hint spend (SpendHint), both keyed by the trusted execution
+// context and the account's present identity sources. *payments.Service satisfies it.
+type HintWallet interface {
+	HintsAvailable(ctx context.Context, accountID uuid.UUID, cxt payments.Context, present []payments.Source) (int, error)
+	SpendHint(ctx context.Context, accountID uuid.UUID, cxt payments.Context, present []payments.Source) (bool, error)
+}
+
+// SetHintWallet installs the payments hint wallet the online-game hint path spends against. It
+// must be called during startup wiring; the default (nil) serves only the free per-game allowance.
+func (svc *Service) SetHintWallet(w HintWallet) {
+	svc.hintWallet = w
+}
+
+// walletContext resolves the payments gate inputs for an account on the current request: the
+// trusted execution context (from the session platform carried on ctx; absent ⇒ untrusted) and
+// the account's present identity sources (which chip/benefit segments are awake, §6).
+func (svc *Service) walletContext(ctx context.Context, accountID uuid.UUID) (payments.Context, []payments.Source, error) {
+	var cxt payments.Context
+	if p, ok := session.PlatformFromContext(ctx); ok {
+		cxt = payments.NewContext(p.Kind, p.Subtype)
+	}
+	ids, err := svc.accounts.Identities(ctx, accountID)
+	if err != nil {
+		return payments.Context{}, nil, err
+	}
+	kinds := make([]string, len(ids))
+	for i, id := range ids {
+		kinds[i] = id.Kind
+	}
+	return cxt, payments.PresentSources(kinds), nil
+}
+
 // SetNudgeClearer installs the hook that marks a mover's pending nudges read after
 // their move commits. It must be called during startup wiring; the default (nil)
 // leaves nudges to be cleared only when the recipient opens the move history or chat.
@@ -107,6 +153,15 @@ func (svc *Service) SetNudgeClearer(fn func(ctx context.Context, gameID, account
 	svc.clearNudges = fn
 }
 
+// SetNudgeExpirer installs the hook that marks every pending nudge in a game read once the
+// game finishes, on any completion path (a closing move, a resignation, a turn-timeout or a
+// forfeit). It must be called during startup wiring; the default (nil) leaves a finished
+// game's nudges to expire only when a recipient opens the move history or chat. The social
+// package wires its ExpireNudges here. Chat messages are deliberately left unread.
+func (svc *Service) SetNudgeExpirer(fn func(ctx context.Context, gameID uuid.UUID) error) {
+	svc.expireNudges = fn
+}
+
 // SetFirstMoveEntropy overrides the entropy source for the first-move draw
 // (docs/ARCHITECTURE.md §6). It must be called during wiring or test setup before any
 // game is created; the production default is crypto/rand and is never overridden.
@@ -699,6 +754,16 @@ func (svc *Service) commit(ctx context.Context, gameID uuid.UUID, g *engine.Game
 	}
 	if c.finished {
 		svc.cache.remove(gameID)
+		// A finished game's nudges are stale, so clear them all here — every completion path
+		// funnels through commit (a closing move, a resignation, a forfeit or a turn-timeout),
+		// and only the move path also clears the mover's nudge on its own. Best-effort like
+		// clearNudges: the finish has committed, so a cleanup failure is logged, not surfaced.
+		// ExpireNudges leaves chat messages unread.
+		if svc.expireNudges != nil {
+			if err := svc.expireNudges(ctx, gameID); err != nil {
+				svc.log.Warn("expire nudges on game finish", zap.Error(err))
+			}
+		}
 	}
 	post, err := svc.store.GetGame(ctx, gameID)
 	if err != nil {
@@ -983,6 +1048,12 @@ func (svc *Service) CountComplaints(ctx context.Context, status string) (int, er
 	return svc.store.CountComplaints(ctx, status)
 }
 
+// CountComplaintsSince counts word complaints filed after since, for the operator alert
+// worker.
+func (svc *Service) CountComplaintsSince(ctx context.Context, since time.Time) (int, error) {
+	return svc.store.CountComplaintsSince(ctx, since)
+}
+
 // ResolveComplaint closes a complaint with an operator disposition (reject /
 // accept_add / accept_remove) and an optional note. An accepted complaint then
 // appears in DictionaryChanges until a rebuilt dictionary is loaded and the
@@ -1027,10 +1098,31 @@ func (svc *Service) MarkChangesApplied(ctx context.Context, variant engine.Varia
 	return svc.store.MarkChangesApplied(ctx, variant.String(), version)
 }
 
-// Hint reveals the top-scoring legal play for the requesting player on their
-// turn, spending one hint from their per-game allowance and then their profile
-// wallet. It returns ErrHintsDisabled, ErrNoHintsLeft or ErrNoHintAvailable as
-// appropriate.
+// hintIdleWindow is how long a vs_ai player must be stuck on a turn (since the robot's last move)
+// before the idle hint unlocks. Mirrors the offline client (lib/hints HINT_GATE_MS = 30 min).
+const hintIdleWindow = 30 * time.Minute
+
+// hintUnlockLeftSeconds is the seconds until g's vs_ai idle hint unlocks for seat, measured from now:
+// the robot's last move (the current turn's start, on the human's turn) plus the window, floored at
+// 0 and ceiled to whole seconds. It is 0 for a non-vs_ai game, when it is not seat's turn, or on the
+// human's first move (MoveCount 0, no robot move yet) — the gate is an anti-frustration aid, not a
+// first-move tax. The client anchors a monotonic countdown to it, so a client clock cannot skew it.
+func hintUnlockLeftSeconds(g Game, seat int, now time.Time) int {
+	if !g.VsAI || g.ToMove != seat || g.MoveCount < 1 {
+		return 0
+	}
+	left := g.TurnStartedAt.Add(hintIdleWindow).Sub(now)
+	if left <= 0 {
+		return 0
+	}
+	return int((left + time.Second - 1) / time.Second) // ceil to whole seconds (no math import)
+}
+
+// Hint reveals the top-scoring legal play for the requesting player on their turn. For a human game
+// it spends one hint from the per-game allowance then the profile wallet (ErrHintsDisabled /
+// ErrNoHintsLeft / ErrNoHintAvailable). For a vs_ai game the hint is unlimited and wallet-free but
+// idle-gated from the server clock (ErrHintLocked until the window elapses) and counts toward no
+// hint statistic.
 func (svc *Service) Hint(ctx context.Context, gameID, accountID uuid.UUID) (HintResult, error) {
 	pre, err := svc.store.GetGame(ctx, gameID)
 	if err != nil {
@@ -1049,13 +1141,40 @@ func (svc *Service) Hint(ctx context.Context, gameID, accountID uuid.UUID) (Hint
 	if !pre.HintsAllowed {
 		return HintResult{}, ErrHintsDisabled
 	}
-	acc, err := svc.accounts.GetByID(ctx, accountID)
+	if pre.VsAI {
+		// vs_ai: unlimited and wallet-free, but idle-gated from the server clock — and counted toward
+		// no hint statistic. Enforce the gate (the client normally pre-gates from the view's
+		// HintUnlockLeftSeconds; this is the authoritative backstop), then serve the top move without
+		// touching the allowance, the wallet or hints_used.
+		if hintUnlockLeftSeconds(pre, seat, svc.clock()) > 0 {
+			return HintResult{}, ErrHintLocked
+		}
+		unlock := svc.locks.lock(gameID)
+		defer unlock()
+		g, err := svc.liveGame(ctx, pre)
+		if err != nil {
+			return HintResult{}, err
+		}
+		move, ok := g.HintView()
+		if !ok {
+			return HintResult{}, ErrNoHintAvailable
+		}
+		return HintResult{Move: move}, nil
+	}
+	cxt, present, err := svc.walletContext(ctx, accountID)
 	if err != nil {
 		return HintResult{}, err
 	}
+	wallet := 0
+	if svc.hintWallet != nil {
+		wallet, err = svc.hintWallet.HintsAvailable(ctx, accountID, cxt, present)
+		if err != nil {
+			return HintResult{}, err
+		}
+	}
 	used := pre.Seats[seat].HintsUsed
 	fromAllowance := used < pre.HintsPerPlayer
-	if !fromAllowance && acc.HintBalance <= 0 {
+	if !fromAllowance && wallet <= 0 {
 		return HintResult{}, ErrNoHintsLeft
 	}
 
@@ -1070,9 +1189,9 @@ func (svc *Service) Hint(ctx context.Context, gameID, accountID uuid.UUID) (Hint
 		return HintResult{}, ErrNoHintAvailable
 	}
 
-	walletAfter := acc.HintBalance
+	walletAfter := wallet
 	if !fromAllowance {
-		spent, err := svc.accounts.SpendHint(ctx, accountID)
+		spent, err := svc.hintWallet.SpendHint(ctx, accountID, cxt, present)
 		if err != nil {
 			return HintResult{}, err
 		}
@@ -1177,6 +1296,8 @@ func (svc *Service) GameState(ctx context.Context, gameID, accountID uuid.UUID)
 		BagLen:         g.BagLen(),
 		HintsRemaining: hintsRemaining(pre.HintsPerPlayer, pre.Seats[seat].HintsUsed, acc.HintBalance),
 		WalletBalance:  acc.HintBalance,
+		// vs_ai idle-hint gate (seconds left; 0 for a human game / first move / not your turn).
+		HintUnlockLeftSeconds: hintUnlockLeftSeconds(pre, seat, svc.clock()),
 	}, nil
 }
 
@@ -1338,30 +1459,53 @@ func (svc *Service) SetupDraws(ctx context.Context, gameID uuid.UUID) ([]SetupDr
 	return svc.store.SetupDraws(ctx, gameID)
 }
 
-// ExportGCG renders a game as GCG text from the journal alone (no dictionary). It
-// is allowed only on a finished game: exporting an in-progress game would leak the
-// full move journal mid-play, so an active game yields ErrGameActive.
-func (svc *Service) ExportGCG(ctx context.Context, gameID uuid.UUID) (string, error) {
+// ExportView returns a finished game with its journal and per-seat display names —
+// the material every export artifact (the GCG text, the PNG render payload) is built
+// from. It is allowed only on a finished game: exporting an in-progress game would
+// leak the full move journal mid-play, so an active game yields ErrGameActive. In an
+// honest-AI game the robot seat is labelled "AI", not its pool name.
+func (svc *Service) ExportView(ctx context.Context, gameID uuid.UUID) (Game, []HistoryMove, []string, error) {
 	g, err := svc.store.GetGame(ctx, gameID)
 	if err != nil {
-		return "", err
+		return Game{}, nil, nil, err
 	}
 	if g.Status != StatusFinished {
-		return "", ErrGameActive
+		return Game{}, nil, nil, ErrGameActive
 	}
 	moves, err := svc.store.GetJournal(ctx, gameID)
 	if err != nil {
-		return "", err
+		return Game{}, nil, nil, err
 	}
 	names := svc.seatNames(ctx, g)
 	if g.VsAI {
-		// Label the robot seat "AI" in an honest-AI game's export, not its pool name.
 		for _, s := range g.Seats {
 			if robot, err := svc.accounts.IsRobot(ctx, s.AccountID); err == nil && robot {
 				names[s.Seat] = aiPlayerName
 			}
 		}
 	}
+	return g, moves, names, nil
+}
+
+// EnsureExportable reports whether a game may be exported (it exists and is
+// finished) without loading the journal — the export-URL mint check.
+func (svc *Service) EnsureExportable(ctx context.Context, gameID uuid.UUID) error {
+	g, err := svc.store.GetGame(ctx, gameID)
+	if err != nil {
+		return err
+	}
+	if g.Status != StatusFinished {
+		return ErrGameActive
+	}
+	return nil
+}
+
+// ExportGCG renders a game as GCG text from the journal alone (no dictionary).
+func (svc *Service) ExportGCG(ctx context.Context, gameID uuid.UUID) (string, error) {
+	g, moves, names, err := svc.ExportView(ctx, gameID)
+	if err != nil {
+		return "", err
+	}
 	return writeGCG(g, names, moves), nil
 }
 
@@ -1440,13 +1584,24 @@ func (svc *Service) voidGame(ctx context.Context, pre Game, g *engine.Game) erro
 	if err != nil {
 		return err
 	}
-	return svc.store.VoidGame(ctx, voidCommit{
+	if err := svc.store.VoidGame(ctx, voidCommit{
 		gameID:    pre.ID,
 		endReason: g.Reason().String(),
 		scores:    scores,
 		now:       svc.clock(),
 		stats:     buildStats(g, statSeats),
-	})
+	}); err != nil {
+		return err
+	}
+	// A voided game is finished (as a draw) but bypasses commit, so clear its now-stale nudges
+	// here too. Best-effort, like the commit path: the void has persisted, so a cleanup failure
+	// is logged, not surfaced.
+	if svc.expireNudges != nil {
+		if err := svc.expireNudges(ctx, pre.ID); err != nil {
+			svc.log.Warn("expire nudges on voided game", zap.Error(err))
+		}
+	}
+	return nil
 }
 
 // replayMove re-applies one journalled move to g through the decoded engine API.
@@ -1613,6 +1768,14 @@ func (svc *Service) lookupWord(variant engine.Variant, version, word string) (bo
 	return present, nil
 }
 
+// DictBytes returns the raw serialized dictionary for the (variant, version) pair
+// from the registry, backing the client-side dictionary download used by the
+// local move preview. It surfaces engine.ErrUnknownVariant /
+// engine.ErrUnknownVersion when that dictionary is not resident.
+func (svc *Service) DictBytes(variant engine.Variant, version string) ([]byte, error) {
+	return svc.registry.DictBytes(variant, version)
+}
+
 // hintsRemaining is a player's remaining hint budget: the unspent per-game
 // allowance plus the profile wallet.
 func hintsRemaining(allowance, used, wallet int) int {

backend/internal/game/store.go

@@ -1040,6 +1040,19 @@ func (s *Store) CountComplaints(ctx context.Context, status string) (int, error)
 	return int(dest.Count), nil
 }
 
+// CountComplaintsSince counts word complaints filed strictly after since — the operator
+// alert worker's "new since the last check" signal.
+func (s *Store) CountComplaintsSince(ctx context.Context, since time.Time) (int, error) {
+	stmt := postgres.SELECT(postgres.COUNT(table.Complaints.ComplaintID).AS("count")).
+		FROM(table.Complaints).
+		WHERE(table.Complaints.CreatedAt.GT(postgres.TimestampzT(since)))
+	var dest struct{ Count int64 }
+	if err := stmt.QueryContext(ctx, s.db, &dest); err != nil {
+		return 0, fmt.Errorf("game: count complaints since: %w", err)
+	}
+	return int(dest.Count), nil
+}
+
 // ActiveGames returns the turn clocks of every in-progress game; the sweeper
 // filters them against the per-move deadline and the player's away window.
 func (s *Store) ActiveGames(ctx context.Context) ([]activeGame, error) {

backend/internal/game/types.go

@@ -65,6 +65,10 @@ var (
 	ErrNoHintsLeft = errors.New("game: no hints remaining")
 	// ErrNoHintAvailable is returned when the player has no legal play to reveal.
 	ErrNoHintAvailable = errors.New("game: no legal move to suggest")
+	// ErrHintLocked is returned when a vs_ai game's idle hint is still gated (the player has not yet
+	// been stuck the idle window since the robot's last move). The client normally pre-gates from
+	// StateView.HintUnlockLeftSeconds, so this is the authoritative server-clock backstop.
+	ErrHintLocked = errors.New("game: hint is not available yet")
 	// ErrGameLimitReached is returned when an account already holds MaxActiveQuickGames
 	// simultaneous quick games and tries to create another game (quick or by invitation).
 	ErrGameLimitReached = errors.New("game: simultaneous game limit reached")
@@ -240,6 +244,11 @@ type StateView struct {
 	// WalletBalance is the player's global hint-wallet balance alone (HintsRemaining folds
 	// it in with the per-game allowance), so the client keeps the wallet live across games.
 	WalletBalance int
+	// HintUnlockLeftSeconds is, for a vs_ai game on the requesting player's turn, the seconds left
+	// until the idle hint unlocks (the robot's last move plus the idle window, from the server clock);
+	// 0 for the human's first move, when it is not their turn, or a non-vs_ai game. The vs_ai hint is
+	// unlimited and wallet-free; this idle gate replaces the allowance/wallet for it.
+	HintUnlockLeftSeconds int
 }
 
 // HistoryMove is one decoded journal row, independent of any dictionary.

backend/internal/inttest/account_test.go

@@ -154,6 +154,53 @@ func TestProvisionTelegramSeedsNewAccountOnly(t *testing.T) {
 	}
 }
 
+// TestProvisionVKSeedsNewAccountOnly checks VK first contact seeds the new account's
+// language, display name and time zone from the launch fields / detected offset, records
+// the vk identity as confirmed (a platform identity), and never overwrites an existing
+// account on a later launch. It also exercises the widened identities.kind CHECK — a
+// 'vk' row must insert.
+func TestProvisionVKSeedsNewAccountOnly(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	ext := "vk-" + uuid.NewString()
+
+	acc, created, err := store.ProvisionVK(ctx, ext, "ru", "Иван Петров", "+03:00")
+	if err != nil {
+		t.Fatalf("provision vk: %v", err)
+	}
+	if !created {
+		t.Error("created = false on first contact, want true")
+	}
+	if acc.PreferredLanguage != "ru" {
+		t.Errorf("PreferredLanguage = %q, want ru", acc.PreferredLanguage)
+	}
+	if acc.DisplayName != "Иван Петров" {
+		t.Errorf("DisplayName = %q, want Иван Петров", acc.DisplayName)
+	}
+	if acc.TimeZone != "+03:00" {
+		t.Errorf("TimeZone = %q, want the seeded +03:00", acc.TimeZone)
+	}
+	// A VK identity is a platform identity: confirmed on insert.
+	if !identityConfirmed(t, account.KindVK, ext) {
+		t.Error("vk identity must be confirmed")
+	}
+
+	// A later launch with different fields returns the same account, unchanged.
+	again, created, err := store.ProvisionVK(ctx, ext, "en", "Other Name", "+09:00")
+	if err != nil {
+		t.Fatalf("re-provision vk: %v", err)
+	}
+	if created {
+		t.Error("created = true on a repeat launch, want false")
+	}
+	if again.ID != acc.ID {
+		t.Errorf("re-provision id = %s, want %s", again.ID, acc.ID)
+	}
+	if again.PreferredLanguage != "ru" || again.DisplayName != "Иван Петров" || again.TimeZone != "+03:00" {
+		t.Errorf("existing account overwritten: lang=%q name=%q tz=%q", again.PreferredLanguage, again.DisplayName, again.TimeZone)
+	}
+}
+
 // TestProvisionSeedsTimeZone checks the create-time time-zone seed across paths: a
 // valid detected offset is stored verbatim (even "+00:00", which is deliberately
 // distinct from the unset "UTC" default), a guest is seeded the same way, and a

backend/internal/inttest/adminemail_test.go

@@ -0,0 +1,83 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/account"
+)
+
+// TestRemoveEmailIdentity erases an account's email identity but refuses when the
+// email is the account's only identity (which would leave it unreachable).
+func TestRemoveEmailIdentity(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+
+	// Email is the only identity → refuse.
+	solo, err := store.ProvisionEmail(ctx, "solo-"+uuid.NewString()+"@example.com", "", "en")
+	if err != nil {
+		t.Fatalf("provision email: %v", err)
+	}
+	if err := store.RemoveEmailIdentity(ctx, solo.ID); !errors.Is(err, account.ErrLastIdentity) {
+		t.Fatalf("remove last identity = %v, want ErrLastIdentity", err)
+	}
+
+	// Telegram + email → erase the email, keep Telegram.
+	tg, err := store.ProvisionByIdentity(ctx, account.KindTelegram, "tg-"+uuid.NewString())
+	if err != nil {
+		t.Fatalf("provision telegram: %v", err)
+	}
+	if err := store.AttachIdentity(ctx, tg.ID, account.KindEmail, "dual-"+uuid.NewString()+"@example.com", true); err != nil {
+		t.Fatalf("attach email: %v", err)
+	}
+	if err := store.RemoveEmailIdentity(ctx, tg.ID); err != nil {
+		t.Fatalf("remove email: %v", err)
+	}
+	ids, err := store.Identities(ctx, tg.ID)
+	if err != nil {
+		t.Fatalf("identities: %v", err)
+	}
+	if len(ids) != 1 || ids[0].Kind != account.KindTelegram {
+		t.Errorf("identities after erase = %+v, want only telegram", ids)
+	}
+}
+
+// TestListUsersEmailExact matches accounts strictly (exactly) by their email identity.
+func TestListUsersEmailExact(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	email := "find-" + uuid.NewString() + "@example.com"
+	acc, err := store.ProvisionEmail(ctx, email, "", "en")
+	if err != nil {
+		t.Fatalf("provision: %v", err)
+	}
+
+	items, err := store.ListUsers(ctx, account.UserFilter{EmailExact: email}, 50, 0)
+	if err != nil {
+		t.Fatalf("list: %v", err)
+	}
+	found := false
+	for _, it := range items {
+		if it.ID == acc.ID {
+			found = true
+		}
+	}
+	if !found {
+		t.Error("the exact email filter did not find the account")
+	}
+
+	other, err := store.ListUsers(ctx, account.UserFilter{EmailExact: "nope-" + uuid.NewString() + "@example.com"}, 50, 0)
+	if err != nil {
+		t.Fatalf("list (no match): %v", err)
+	}
+	for _, it := range other {
+		if it.ID == acc.ID {
+			t.Error("a non-matching email filter must not return the account")
+		}
+	}
+}

backend/internal/inttest/banner_console_test.go

@@ -15,13 +15,15 @@ import (
 
 	"scrabble/backend/internal/account"
 	"scrabble/backend/internal/ads"
+	"scrabble/backend/internal/payments"
 	"scrabble/backend/internal/server"
 )
 
 // bannerServer assembles a console-capable server with the ads domain wired.
-func bannerServer(t *testing.T) (*server.Server, *ads.Service) {
+func bannerServer(t *testing.T) (*server.Server, *ads.Service, *payments.Service) {
 	t.Helper()
 	adsSvc := ads.NewService(ads.NewStore(testDB))
+	paySvc := newPaymentsService()
 	srv := server.New(":0", server.Deps{
 		Logger:   zap.NewNop(),
 		Accounts: account.NewStore(testDB),
@@ -29,8 +31,9 @@ func bannerServer(t *testing.T) (*server.Server, *ads.Service) {
 		Registry: testRegistry,
 		DictDir:  dictDir(),
 		Ads:      adsSvc,
+		Payments: paySvc,
 	})
-	return srv, adsSvc
+	return srv, adsSvc, paySvc
 }
 
 // findCampaign returns the id of the campaign with the given name, or fails.
@@ -71,7 +74,7 @@ func defaultCampaign(t *testing.T, svc *ads.Service) ads.Campaign {
 // reorder/delete.
 func TestBannerConsoleCRUD(t *testing.T) {
 	ctx := context.Background()
-	srv, adsSvc := bannerServer(t)
+	srv, adsSvc, _ := bannerServer(t)
 	h := srv.Handler()
 	base := "http://admin.test/_gm"
 	const origin = "http://admin.test"
@@ -151,7 +154,7 @@ func TestBannerConsoleCRUD(t *testing.T) {
 // unrelated campaign's URL must be refused.
 func TestBannerMessageOwnership(t *testing.T) {
 	ctx := context.Background()
-	srv, adsSvc := bannerServer(t)
+	srv, adsSvc, _ := bannerServer(t)
 	h := srv.Handler()
 	base := "http://admin.test/_gm"
 	const origin = "http://admin.test"
@@ -192,8 +195,9 @@ func TestBannerMessageOwnership(t *testing.T) {
 type profileBanner struct {
 	Banner *struct {
 		Campaigns []struct {
-			Weight   int      `json:"weight"`
-			Messages []string `json:"messages"`
+			Weight     int      `json:"weight"`
+			Messages   []string `json:"messages"`
+			OverrideBg string   `json:"override_bg"`
 		} `json:"campaigns"`
 		Timings struct {
 			HoldMs int `json:"hold_ms"`
@@ -206,10 +210,11 @@ type profileBanner struct {
 // wallet each suppress it.
 func TestBannerProfileEligibility(t *testing.T) {
 	ctx := context.Background()
-	srv, _ := bannerServer(t)
+	srv, _, pay := bannerServer(t)
 	accounts := account.NewStore(testDB)
 	id := provisionAccount(t)
 
+	// getBanner fetches the profile banner with no platform header (an untrusted context).
 	getBanner := func() profileBanner {
 		t.Helper()
 		rec := userGet(t, srv, "/api/v1/user/profile", id)
@@ -222,10 +227,27 @@ func TestBannerProfileEligibility(t *testing.T) {
 		}
 		return p
 	}
+	// getBannerTG fetches the profile banner in a trusted Telegram context — the account's
+	// telegram identity makes telegram the applicable origin for its benefits.
+	getBannerTG := func() profileBanner {
+		t.Helper()
+		rec := httptest.NewRecorder()
+		req := httptest.NewRequest(http.MethodGet, "/api/v1/user/profile", nil)
+		req.Header.Set("X-User-ID", id.String())
+		req.Header.Set("X-Platform", "telegram/android")
+		srv.Handler().ServeHTTP(rec, req)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("profile = %d, want 200", rec.Code)
+		}
+		var p profileBanner
+		if err := json.Unmarshal(rec.Body.Bytes(), &p); err != nil {
+			t.Fatalf("decode profile: %v", err)
+		}
+		return p
+	}
 
-	// A free account with an empty hint wallet and no role is eligible.
-	p := getBanner()
-	if p.Banner == nil || len(p.Banner.Campaigns) == 0 || p.Banner.Timings.HoldMs <= 0 {
+	// A free account with no role and no benefit is eligible.
+	if p := getBanner(); p.Banner == nil || len(p.Banner.Campaigns) == 0 || p.Banner.Timings.HoldMs <= 0 {
 		t.Fatalf("eligible account: banner=%v", p.Banner)
 	}
 
@@ -240,19 +262,31 @@ func TestBannerProfileEligibility(t *testing.T) {
 		t.Fatalf("revoke role: %v", err)
 	}
 
-	// A non-empty hint wallet suppresses it.
-	if _, err := accounts.GrantHints(ctx, id, 5); err != nil {
+	// A hint wallet no longer suppresses the banner — hints and no-ads are distinct benefits now.
+	if err := pay.Grant(ctx, id, payments.SourceTelegram, 5, 0, false); err != nil {
 		t.Fatalf("grant hints: %v", err)
 	}
-	if p := getBanner(); p.Banner != nil {
-		t.Fatal("a non-empty hint wallet still shows the banner")
+	if p := getBannerTG(); p.Banner == nil {
+		t.Fatal("a hint wallet must NOT suppress the banner")
+	}
+
+	// An active no-ads benefit applicable in the context suppresses the banner.
+	if err := pay.Grant(ctx, id, payments.SourceTelegram, 0, 30, false); err != nil {
+		t.Fatalf("grant no-ads: %v", err)
+	}
+	if p := getBannerTG(); p.Banner != nil {
+		t.Fatal("an active no-ads benefit must suppress the banner")
+	}
+	// Fail-closed: without a trusted platform the same benefit does not apply, so the banner shows.
+	if p := getBanner(); p.Banner == nil {
+		t.Fatal("an untrusted context must not apply the no-ads benefit (banner should show)")
 	}
 }
 
 // TestBannerSurvivesProfileUpdate guards that a profile update (e.g. a language switch) returns the
 // banner block too, so the client's profile keeps the banner instead of losing it until reload.
 func TestBannerSurvivesProfileUpdate(t *testing.T) {
-	srv, _ := bannerServer(t)
+	srv, _, _ := bannerServer(t)
 	id := provisionAccount(t)
 
 	body := `{"display_name":"Tester","preferred_language":"ru","time_zone":"UTC","away_start":"00:00",` +
@@ -274,3 +308,142 @@ func TestBannerSurvivesProfileUpdate(t *testing.T) {
 		t.Fatalf("profile update dropped the banner block: %v", p.Banner)
 	}
 }
+
+// TestBannerConsoleColorsAndUrgent drives the colour-override + urgent editor over
+// HTTP against real Postgres: an incomplete or malformed colour set is refused, a
+// full two-set override + urgent round-trips through the store (exercising the new
+// columns and CHECK constraints), clearing the sets removes the override, and the
+// default campaign stays plain (colours + urgent are ignored for it).
+func TestBannerConsoleColorsAndUrgent(t *testing.T) {
+	ctx := context.Background()
+	srv, adsSvc, _ := bannerServer(t)
+	h := srv.Handler()
+	base := "http://admin.test/_gm"
+	const origin = "http://admin.test"
+
+	name := "Brand-" + uuid.NewString()[:8]
+	if code, body := consoleDo(h, http.MethodPost, base+"/banners", "name="+name+"&weight=20&enabled=on", origin); code != http.StatusOK || !strings.Contains(body, "Created") {
+		t.Fatalf("create = %d, has Created=%v", code, strings.Contains(body, "Created"))
+	}
+	id := findCampaign(t, adsSvc, name)
+	t.Cleanup(func() { _ = adsSvc.DeleteCampaign(ctx, id) })
+	detail := base + "/banners/" + id.String()
+
+	// A partial colour set (a missing colour) is refused by validation.
+	partial := "name=" + name + "&weight=20&enabled=on&override_all_on=on&override_bg=%23aa0000&override_fg=&override_link=%23ffdd00"
+	if code, b := consoleDo(h, http.MethodPost, detail, partial, origin); code != http.StatusOK || !strings.Contains(b, "Not saved") {
+		t.Fatalf("partial colour = %d, has 'Not saved'=%v", code, strings.Contains(b, "Not saved"))
+	}
+	// A malformed hex is refused.
+	badHex := "name=" + name + "&weight=20&enabled=on&override_all_on=on&override_bg=red&override_fg=%23ffffff&override_link=%23ffdd00"
+	if code, b := consoleDo(h, http.MethodPost, detail, badHex, origin); code != http.StatusOK || !strings.Contains(b, "Not saved") {
+		t.Fatalf("bad hex = %d, has 'Not saved'=%v", code, strings.Contains(b, "Not saved"))
+	}
+	// Both colour sets + urgent persist and round-trip through the store.
+	full := "name=" + name + "&weight=20&enabled=on&urgent=on" +
+		"&override_all_on=on&override_bg=%23aa0000&override_fg=%23ffffff&override_link=%23ffdd00" +
+		"&override_dark_on=on&override_bg_dark=%23330000&override_fg_dark=%23eeeeee&override_link_dark=%23ffcc00"
+	if code, b := consoleDo(h, http.MethodPost, detail, full, origin); code != http.StatusOK || !strings.Contains(b, "Saved") {
+		t.Fatalf("full save = %d, has Saved=%v", code, strings.Contains(b, "Saved"))
+	}
+	cm, err := adsSvc.Campaign(ctx, id)
+	if err != nil {
+		t.Fatalf("read campaign: %v", err)
+	}
+	if cm.OverrideAll == nil || cm.OverrideAll.Bg != "#aa0000" || cm.OverrideAll.Fg != "#ffffff" || cm.OverrideAll.Link != "#ffdd00" {
+		t.Fatalf("override all = %+v", cm.OverrideAll)
+	}
+	if cm.OverrideDark == nil || cm.OverrideDark.Bg != "#330000" || cm.OverrideDark.Fg != "#eeeeee" || cm.OverrideDark.Link != "#ffcc00" {
+		t.Fatalf("override dark = %+v", cm.OverrideDark)
+	}
+	if !cm.Urgent {
+		t.Fatal("urgent not persisted")
+	}
+	// Clearing the sets (both checkboxes off, urgent off) removes the override.
+	if code, _ := consoleDo(h, http.MethodPost, detail, "name="+name+"&weight=20&enabled=on", origin); code != http.StatusOK {
+		t.Fatalf("clear = %d", code)
+	}
+	if cm, _ := adsSvc.Campaign(ctx, id); cm.OverrideAll != nil || cm.OverrideDark != nil || cm.Urgent {
+		t.Fatalf("override not cleared: all=%v dark=%v urgent=%v", cm.OverrideAll, cm.OverrideDark, cm.Urgent)
+	}
+
+	// The default campaign stays plain: submitted colours + urgent are ignored for it.
+	def := defaultCampaign(t, adsSvc)
+	defForm := "name=Default+%28house%29&urgent=on&override_all_on=on&override_bg=%23aa0000&override_fg=%23ffffff&override_link=%23ffdd00"
+	if code, _ := consoleDo(h, http.MethodPost, base+"/banners/"+def.ID.String(), defForm, origin); code != http.StatusOK {
+		t.Fatalf("update default = %d", code)
+	}
+	if again := defaultCampaign(t, adsSvc); again.OverrideAll != nil || again.OverrideDark != nil || again.Urgent {
+		t.Fatalf("default not plain: all=%v dark=%v urgent=%v", again.OverrideAll, again.OverrideDark, again.Urgent)
+	}
+}
+
+// TestBannerUrgentBypassesEligibility checks the urgent flag at the profile level:
+// an urgent campaign preempts the feed (only it shows, with its colours) and reaches
+// every viewer — including the no_banner role and a non-empty hint wallet that
+// otherwise suppress the banner.
+func TestBannerUrgentBypassesEligibility(t *testing.T) {
+	ctx := context.Background()
+	srv, adsSvc, _ := bannerServer(t)
+	accounts := account.NewStore(testDB)
+	id := provisionAccount(t)
+
+	urgentID, err := adsSvc.CreateCampaign(ctx, ads.Campaign{
+		Name: "Alert-" + uuid.NewString()[:8], Weight: 10, Enabled: true, Urgent: true,
+		OverrideAll: &ads.ColorSet{Bg: "#aa0000", Fg: "#ffffff", Link: "#ffdd00"},
+	})
+	if err != nil {
+		t.Fatalf("create urgent: %v", err)
+	}
+	t.Cleanup(func() { _ = adsSvc.DeleteCampaign(ctx, urgentID) })
+	if _, err := adsSvc.AddMessage(ctx, urgentID, "System maintenance tonight", "Ночью тех.работы"); err != nil {
+		t.Fatalf("add urgent message: %v", err)
+	}
+
+	get := func() profileBanner {
+		t.Helper()
+		rec := userGet(t, srv, "/api/v1/user/profile", id)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("profile = %d", rec.Code)
+		}
+		var p profileBanner
+		if err := json.Unmarshal(rec.Body.Bytes(), &p); err != nil {
+			t.Fatalf("decode: %v", err)
+		}
+		return p
+	}
+	assertUrgentOnly := func(what string, p profileBanner) {
+		t.Helper()
+		if p.Banner == nil {
+			t.Fatalf("%s: no banner", what)
+		}
+		if len(p.Banner.Campaigns) != 1 {
+			t.Fatalf("%s: %d campaigns, want only the urgent one (default preempted)", what, len(p.Banner.Campaigns))
+		}
+		c := p.Banner.Campaigns[0]
+		if len(c.Messages) != 1 || c.Messages[0] != "System maintenance tonight" {
+			t.Fatalf("%s: messages = %v, want only the urgent one", what, c.Messages)
+		}
+		if c.OverrideBg != "#aa0000" {
+			t.Fatalf("%s: override_bg = %q, want #aa0000", what, c.OverrideBg)
+		}
+	}
+
+	// A normal viewer sees only the urgent campaign (the default is preempted).
+	assertUrgentOnly("eligible", get())
+
+	// The no_banner role no longer suppresses it — urgent reaches everyone.
+	if err := accounts.GrantRole(ctx, id, account.RoleNoBanner); err != nil {
+		t.Fatalf("grant role: %v", err)
+	}
+	assertUrgentOnly("no_banner", get())
+	if err := accounts.RevokeRole(ctx, id, account.RoleNoBanner); err != nil {
+		t.Fatalf("revoke role: %v", err)
+	}
+
+	// A non-empty hint wallet no longer suppresses it either.
+	if _, err := accounts.GrantHints(ctx, id, 5); err != nil {
+		t.Fatalf("grant hints: %v", err)
+	}
+	assertUrgentOnly("hints", get())
+}

backend/internal/inttest/chatread_test.go

@@ -138,6 +138,65 @@ func TestNudgeClearedByMove(t *testing.T) {
 	}
 }
 
+// TestGameCompletionExpiresNudgesKeepsChat checks that finishing a game by turn-timeout marks every
+// pending nudge in it read — the lobby's nudge badge is stale once the game is over — while leaving
+// real chat messages unread. It reproduces the reported bug: the timeout path commits the finish
+// directly, bypassing the move path's per-mover nudge clear, so without a completion-driven expiry
+// the awaited seat's nudge lingered as a badge on the finished game.
+func TestGameCompletionExpiresNudgesKeepsChat(t *testing.T) {
+	ctx := context.Background()
+	gameSvc := newGameService()
+	socialSvc := newSocialService()
+	gameSvc.SetNudgeExpirer(socialSvc.ExpireNudges)
+
+	seats := []uuid.UUID{provisionAccount(t), provisionAccount(t)}
+	g, err := gameSvc.Create(ctx, game.CreateParams{
+		Variant: engine.VariantEnglish, Seats: seats, TurnTimeout: time.Hour, Seed: openingSeed(t),
+	})
+	if err != nil {
+		t.Fatalf("create: %v", err)
+	}
+
+	// Seat 1 nudges the to-move seat 0 (the awaited player), and seat 0 posts a real chat message,
+	// which seat 1 then holds unread. So before the timeout each side has exactly one unread entry:
+	// seat 0 a nudge, seat 1 a message — letting HasUnread isolate each kind.
+	if _, err := socialSvc.Nudge(ctx, g.ID, seats[1]); err != nil {
+		t.Fatalf("nudge: %v", err)
+	}
+	if _, err := socialSvc.PostMessage(ctx, g.ID, seats[0], "good luck", ""); err != nil {
+		t.Fatalf("post message: %v", err)
+	}
+	if unread, _ := socialSvc.HasUnread(ctx, g.ID, seats[0]); !unread {
+		t.Fatal("seat 0 should hold the nudge unread before the timeout")
+	}
+	if unread, _ := socialSvc.HasUnread(ctx, g.ID, seats[1]); !unread {
+		t.Fatal("seat 1 should hold the message unread before the timeout")
+	}
+
+	// Age the turn past its deadline and time seat 0 out; an empty away window keeps this
+	// deterministic regardless of the wall clock. The sweep finishes the game through the direct
+	// commit path, never the move path.
+	backdate(t, g.ID, time.Now().UTC().Add(-2*time.Hour))
+	setAway(t, seats[0], "UTC", "00:00", "00:00")
+	if n, err := gameSvc.SweepTimeouts(ctx, time.Now().UTC()); err != nil || n < 1 {
+		t.Fatalf("sweep swept %d (err %v), want >= 1", n, err)
+	}
+	if status, reason := gameStatus(t, gameSvc, g.ID); status != game.StatusFinished || reason != "timeout" {
+		t.Fatalf("game not timed out: status %q reason %q", status, reason)
+	}
+
+	// The nudge is stale on a finished game and must be cleared; the chat message must survive.
+	if unread, _ := socialSvc.HasUnread(ctx, g.ID, seats[0]); unread {
+		t.Error("the nudge should be expired once the game has finished")
+	}
+	if unread, _ := socialSvc.HasUnread(ctx, g.ID, seats[1]); !unread {
+		t.Error("a real chat message must stay unread after the game finishes")
+	}
+	if msg, _ := socialSvc.HasUnreadMessage(ctx, g.ID, seats[1]); !msg {
+		t.Error("the chat message must remain flagged as an unread message after completion")
+	}
+}
+
 // TestChatToRobotIsBornRead checks a text message to a disguised robot opponent (a pooled
 // robot substituted into an ordinary, non-AI game) is born read: the robot never opens the
 // chat, so the message must not linger unread (skewing the count and the read metric).

backend/internal/inttest/delete_test.go

@@ -0,0 +1,322 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/account"
+	"scrabble/backend/internal/accountdelete"
+	"scrabble/backend/internal/engine"
+	"scrabble/backend/internal/game"
+)
+
+// deletedFields reads a tombstoned account's retained real name and its deleted_at.
+func deletedFields(t *testing.T, accountID uuid.UUID) (name string, deletedAt sql.NullTime) {
+	t.Helper()
+	var dn sql.NullString
+	err := testDB.QueryRowContext(context.Background(),
+		"SELECT deleted_display_name, deleted_at FROM accounts WHERE account_id = $1", accountID).
+		Scan(&dn, &deletedAt)
+	if err != nil {
+		t.Fatalf("read deleted fields %s: %v", accountID, err)
+	}
+	return dn.String, deletedAt
+}
+
+// TestAnonymizeAndTombstone: deletion journals + frees the credentials, tombstones the
+// account, scrubs the live name while retaining the real one, and frees the creds for a
+// new account to reuse.
+func TestAnonymizeAndTombstone(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	deleter := accountdelete.NewDeleter(testDB)
+
+	acc, _, err := store.ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "ru", "handle", "Иван", "+03:00")
+	if err != nil {
+		t.Fatalf("provision: %v", err)
+	}
+	email := "del-" + uuid.NewString() + "@example.com"
+	if err := store.AttachIdentity(ctx, acc.ID, account.KindEmail, email, true); err != nil {
+		t.Fatalf("attach email: %v", err)
+	}
+	before, err := store.GetByID(ctx, acc.ID)
+	if err != nil {
+		t.Fatalf("load before: %v", err)
+	}
+
+	if err := deleter.AnonymizeAndTombstone(ctx, acc.ID); err != nil {
+		t.Fatalf("delete: %v", err)
+	}
+
+	// The live identities are gone.
+	if ids, err := store.Identities(ctx, acc.ID); err != nil || len(ids) != 0 {
+		t.Fatalf("identities after delete = %+v (err %v), want none", ids, err)
+	}
+	// Both credentials are journalled with reason=delete.
+	got := retainedRows(t, acc.ID)
+	if len(got) != 2 {
+		t.Fatalf("retained rows = %+v, want 2", got)
+	}
+	for _, r := range got {
+		if r.reason != "delete" {
+			t.Errorf("retained reason = %q, want delete", r.reason)
+		}
+	}
+	// The live name is scrubbed; the real one is retained; deleted_at is set.
+	after, err := store.GetByID(ctx, acc.ID)
+	if err != nil {
+		t.Fatalf("load after: %v", err)
+	}
+	if after.DisplayName != accountdelete.AnonymizedName {
+		t.Errorf("live display name = %q, want %q", after.DisplayName, accountdelete.AnonymizedName)
+	}
+	name, deletedAt := deletedFields(t, acc.ID)
+	if name != before.DisplayName {
+		t.Errorf("retained name = %q, want %q", name, before.DisplayName)
+	}
+	if !deletedAt.Valid || time.Since(deletedAt.Time) > time.Minute {
+		t.Errorf("deleted_at = %+v, want a recent timestamp", deletedAt)
+	}
+	// The credentials are free: a new account can claim the same email.
+	other, _, err := store.ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "en", "", "Other", "")
+	if err != nil {
+		t.Fatalf("provision other: %v", err)
+	}
+	if err := store.AttachIdentity(ctx, other.ID, account.KindEmail, email, true); err != nil {
+		t.Fatalf("email should be free after deletion, got: %v", err)
+	}
+}
+
+// TestDeletionDossierReaders: after deletion the admin readers expose the credential
+// journal and the tombstone dossier.
+func TestDeletionDossierReaders(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	deleter := accountdelete.NewDeleter(testDB)
+
+	acc, _, err := store.ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "ru", "handle", "Иван", "+03:00")
+	if err != nil {
+		t.Fatalf("provision: %v", err)
+	}
+	if err := store.AttachIdentity(ctx, acc.ID, account.KindEmail, "dos-"+uuid.NewString()+"@example.com", true); err != nil {
+		t.Fatalf("attach email: %v", err)
+	}
+	if err := deleter.AnonymizeAndTombstone(ctx, acc.ID); err != nil {
+		t.Fatalf("delete: %v", err)
+	}
+
+	rets, err := store.RetainedIdentities(ctx, acc.ID)
+	if err != nil || len(rets) != 2 {
+		t.Fatalf("RetainedIdentities = (%+v, %v), want 2 rows", rets, err)
+	}
+	for _, r := range rets {
+		if r.Reason != "delete" {
+			t.Errorf("retained reason = %q, want delete", r.Reason)
+		}
+	}
+	info, err := store.DeletionInfo(ctx, acc.ID)
+	if err != nil {
+		t.Fatalf("DeletionInfo: %v", err)
+	}
+	if info.DeletedAt == nil {
+		t.Error("DeletionInfo.DeletedAt should be set")
+	}
+	if info.DeletedDisplayName != "Иван" {
+		t.Errorf("DeletionInfo.DeletedDisplayName = %q, want Иван", info.DeletedDisplayName)
+	}
+}
+
+// listHasID reports whether the user list contains accountID.
+func listHasID(items []account.UserListItem, id uuid.UUID) bool {
+	for _, it := range items {
+		if it.ID == id {
+			return true
+		}
+	}
+	return false
+}
+
+// TestUserListDeletedFilter: a tombstoned account is hidden from the default People list and
+// shown only under the Deleted scope.
+func TestUserListDeletedFilter(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	deleter := accountdelete.NewDeleter(testDB)
+
+	live, _, err := store.ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "en", "", "Live", "")
+	if err != nil {
+		t.Fatalf("provision live: %v", err)
+	}
+	goneTg := "tg-" + uuid.NewString()
+	gone, _, err := store.ProvisionTelegram(ctx, goneTg, "en", "", "Gone", "")
+	if err != nil {
+		t.Fatalf("provision gone: %v", err)
+	}
+	goneEmail := "gone-" + uuid.NewString() + "@example.com"
+	if err := store.AttachIdentity(ctx, gone.ID, account.KindEmail, goneEmail, true); err != nil {
+		t.Fatalf("attach gone email: %v", err)
+	}
+	if err := deleter.AnonymizeAndTombstone(ctx, gone.ID); err != nil {
+		t.Fatalf("delete: %v", err)
+	}
+
+	people, err := store.ListUsers(ctx, account.UserFilter{}, 5000, 0)
+	if err != nil {
+		t.Fatalf("list people: %v", err)
+	}
+	if listHasID(people, gone.ID) {
+		t.Error("a deleted account must not appear in the default People list")
+	}
+	if !listHasID(people, live.ID) {
+		t.Error("a live account must appear in the default People list")
+	}
+	deleted, err := store.ListUsers(ctx, account.UserFilter{Deleted: true}, 5000, 0)
+	if err != nil {
+		t.Fatalf("list deleted: %v", err)
+	}
+	if !listHasID(deleted, gone.ID) {
+		t.Error("a deleted account must appear in the Deleted list")
+	}
+	if listHasID(deleted, live.ID) {
+		t.Error("a live account must not appear in the Deleted list")
+	}
+
+	// A search spans both lists and reaches the retention journal: a deleted account is
+	// still found by the email and external id it held (both moved to retained_identities
+	// on deletion, out of the live identities table).
+	byEmail, err := store.ListUsers(ctx, account.UserFilter{EmailExact: goneEmail}, 5000, 0)
+	if err != nil {
+		t.Fatalf("search by email: %v", err)
+	}
+	if !listHasID(byEmail, gone.ID) {
+		t.Error("a deleted account must be found by the email it held (retention journal)")
+	}
+	byExt, err := store.ListUsers(ctx, account.UserFilter{ExternalIDMask: goneTg}, 5000, 0)
+	if err != nil {
+		t.Fatalf("search by external id: %v", err)
+	}
+	if !listHasID(byExt, gone.ID) {
+		t.Error("a deleted account must be found by the external id it held (retention journal)")
+	}
+}
+
+// TestConfirmCodeClearsGuest: confirming an email on a guest via ConfirmCode promotes it to
+// a durable account (defence-in-depth — no confirmed-email path leaves is_guest set).
+func TestConfirmCodeClearsGuest(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	mailer := &capturingMailer{}
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
+
+	guest, err := store.ProvisionGuest(ctx, "")
+	if err != nil {
+		t.Fatalf("provision guest: %v", err)
+	}
+	email := "cc-" + uuid.NewString() + "@example.com"
+	if err := svc.RequestCode(ctx, guest.ID, email); err != nil {
+		t.Fatalf("request code: %v", err)
+	}
+	if _, err := svc.ConfirmCode(ctx, guest.ID, email, sixDigit.FindString(mailer.lastBody)); err != nil {
+		t.Fatalf("confirm code: %v", err)
+	}
+	after, err := store.GetByID(ctx, guest.ID)
+	if err != nil {
+		t.Fatalf("load: %v", err)
+	}
+	if after.IsGuest {
+		t.Error("confirming an email must clear the guest flag")
+	}
+}
+
+// TestDropAllRobotGames drops the deletee's solo vs-AI game but keeps a game with a human
+// opponent.
+func TestDropAllRobotGames(t *testing.T) {
+	ctx := context.Background()
+	gsvc := newGameService()
+	robots := newRobotService(t, gsvc)
+	if err := robots.EnsurePool(ctx); err != nil {
+		t.Fatalf("ensure pool: %v", err)
+	}
+	mm := newMatchmaker(t, robots, time.Minute, 0)
+	deleter := accountdelete.NewDeleter(testDB)
+
+	user := provisionAccount(t)
+	other := provisionAccount(t)
+
+	aiRes, err := mm.StartVsAI(ctx, user, engine.VariantEnglish, true)
+	if err != nil {
+		t.Fatalf("start vs AI: %v", err)
+	}
+	humanGame, err := gsvc.Create(ctx, game.CreateParams{
+		Variant: engine.VariantEnglish, Seats: []uuid.UUID{user, other}, TurnTimeout: time.Hour, Seed: 1,
+	})
+	if err != nil {
+		t.Fatalf("create human game: %v", err)
+	}
+
+	n, err := deleter.DropAllRobotGames(ctx, user)
+	if err != nil {
+		t.Fatalf("drop: %v", err)
+	}
+	if n != 1 {
+		t.Fatalf("dropped %d games, want 1 (the vs-AI game)", n)
+	}
+	if _, err := gsvc.GameByID(ctx, aiRes.Game.ID); err == nil {
+		t.Error("the vs-AI game should be dropped")
+	}
+	if _, err := gsvc.GameByID(ctx, humanGame.ID); err != nil {
+		t.Errorf("the human game should be kept, got: %v", err)
+	}
+}
+
+// TestDeleteStepUpEmail: an email account's delete code verifies (wrong code rejected, no
+// deeplink in the mail); a platform-only account has no email and cannot request a code.
+func TestDeleteStepUpEmail(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	mailer := &capturingMailer{}
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
+
+	acc, err := store.ProvisionByIdentity(ctx, account.KindTelegram, "tg-"+uuid.NewString())
+	if err != nil {
+		t.Fatalf("provision: %v", err)
+	}
+	if err := store.AttachIdentity(ctx, acc.ID, account.KindEmail, "del-"+uuid.NewString()+"@example.com", true); err != nil {
+		t.Fatalf("attach email: %v", err)
+	}
+	if has, err := svc.HasEmail(ctx, acc.ID); err != nil || !has {
+		t.Fatalf("HasEmail = (%v, %v), want true", has, err)
+	}
+	if err := svc.RequestDeleteCode(ctx, acc.ID); err != nil {
+		t.Fatalf("request delete code: %v", err)
+	}
+	if strings.Contains(mailer.lastBody, "/confirm/") {
+		t.Error("a delete email must not carry a one-tap deeplink")
+	}
+	code := sixDigit.FindString(mailer.lastBody)
+	if err := svc.VerifyDeleteCode(ctx, acc.ID, "000000"); err == nil {
+		t.Error("a wrong delete code must be rejected")
+	}
+	if err := svc.VerifyDeleteCode(ctx, acc.ID, code); err != nil {
+		t.Fatalf("verify correct delete code: %v", err)
+	}
+
+	noEmail, err := store.ProvisionByIdentity(ctx, account.KindTelegram, "tg-"+uuid.NewString())
+	if err != nil {
+		t.Fatalf("provision no-email: %v", err)
+	}
+	if has, _ := svc.HasEmail(ctx, noEmail.ID); has {
+		t.Error("HasEmail must be false for a platform-only account")
+	}
+	if err := svc.RequestDeleteCode(ctx, noEmail.ID); !errors.Is(err, account.ErrNoEmail) {
+		t.Errorf("request delete for no-email account = %v, want ErrNoEmail", err)
+	}
+}

backend/internal/inttest/email_test.go

@@ -19,8 +19,8 @@ import (
 // recover the confirm-code from the body.
 type capturingMailer struct{ lastBody string }
 
-func (m *capturingMailer) Send(_ context.Context, _, _, body string) error {
-	m.lastBody = body
+func (m *capturingMailer) Send(_ context.Context, msg account.Message) error {
+	m.lastBody = msg.Text
 	return nil
 }
 
@@ -32,7 +32,7 @@ func TestEmailConfirmFlow(t *testing.T) {
 	ctx := context.Background()
 	store := account.NewStore(testDB)
 	mailer := &capturingMailer{}
-	svc := account.NewEmailService(store, mailer)
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
 
 	acc := provisionAccount(t)
 	email := "user-" + uuid.NewString() + "@example.com"
@@ -67,7 +67,7 @@ func TestEmailAlreadyTakenByAnotherAccount(t *testing.T) {
 	ctx := context.Background()
 	store := account.NewStore(testDB)
 	mailer := &capturingMailer{}
-	svc := account.NewEmailService(store, mailer)
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
 
 	owner := provisionAccount(t)
 	email := "taken-" + uuid.NewString() + "@example.com"
@@ -89,7 +89,7 @@ func TestEmailCodeExpires(t *testing.T) {
 	ctx := context.Background()
 	store := account.NewStore(testDB)
 	mailer := &capturingMailer{}
-	svc := account.NewEmailService(store, mailer)
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
 
 	acc := provisionAccount(t)
 	email := "expire-" + uuid.NewString() + "@example.com"
@@ -111,7 +111,7 @@ func TestEmailTooManyAttempts(t *testing.T) {
 	ctx := context.Background()
 	store := account.NewStore(testDB)
 	mailer := &capturingMailer{}
-	svc := account.NewEmailService(store, mailer)
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
 
 	acc := provisionAccount(t)
 	email := "lock-" + uuid.NewString() + "@example.com"
@@ -203,10 +203,10 @@ func TestUpdateProfileOffsetTimezone(t *testing.T) {
 func TestEmailLoginFlow(t *testing.T) {
 	ctx := context.Background()
 	mailer := &capturingMailer{}
-	svc := account.NewEmailService(account.NewStore(testDB), mailer)
+	svc := account.NewEmailService(account.NewStore(testDB), mailer, "https://erudit-game.ru")
 	email := "login-" + uuid.NewString() + "@example.com"
 
-	accountID, err := svc.RequestLoginCode(ctx, email, "+02:00")
+	accountID, err := svc.RequestLoginCode(ctx, email, "+02:00", "en", false)
 	if err != nil {
 		t.Fatalf("request login code: %v", err)
 	}
@@ -233,7 +233,7 @@ func TestEmailLoginFlow(t *testing.T) {
 	}
 
 	// A second login for the same email is the returning user: same account.
-	if _, err := svc.RequestLoginCode(ctx, email, ""); err != nil {
+	if _, err := svc.RequestLoginCode(ctx, email, "", "ru", false); err != nil {
 		t.Fatalf("second request: %v", err)
 	}
 	acc2, err := svc.LoginWithCode(ctx, email, sixDigit.FindString(mailer.lastBody))
@@ -244,3 +244,210 @@ func TestEmailLoginFlow(t *testing.T) {
 		t.Errorf("returning login account = %s, want %s", acc2.ID, accountID)
 	}
 }
+
+// TestEmailLoginProvisionsGuestUntilConfirmed covers the squat fix: an email-login
+// account is a guest (reapable, so an abandoned never-confirmed login frees its
+// address) until the code is confirmed, which promotes it to a durable account.
+func TestEmailLoginProvisionsGuestUntilConfirmed(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	mailer := &capturingMailer{}
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
+	email := "squat-" + uuid.NewString() + "@example.com"
+
+	id, err := svc.RequestLoginCode(ctx, email, "", "en", false)
+	if err != nil {
+		t.Fatalf("request login code: %v", err)
+	}
+	before, err := store.GetByID(ctx, id)
+	if err != nil {
+		t.Fatalf("get before confirm: %v", err)
+	}
+	if !before.IsGuest {
+		t.Error("an unconfirmed email-login account must be a guest so it is reapable")
+	}
+
+	if _, err := svc.LoginWithCode(ctx, email, sixDigit.FindString(mailer.lastBody)); err != nil {
+		t.Fatalf("login: %v", err)
+	}
+	after, err := store.GetByID(ctx, id)
+	if err != nil {
+		t.Fatalf("get after confirm: %v", err)
+	}
+	if after.IsGuest {
+		t.Error("confirming the login must clear the guest flag (promote to durable)")
+	}
+}
+
+// TestEmailLoginPWAOmitsLink: a login requested from an installed PWA (pwa=true) mails only the
+// code — no one-tap confirm link, which would otherwise open in a separate browser out of the
+// PWA's reach. A non-PWA request keeps the link.
+func TestEmailLoginPWAOmitsLink(t *testing.T) {
+	ctx := context.Background()
+	mailer := &capturingMailer{}
+	svc := account.NewEmailService(account.NewStore(testDB), mailer, "https://erudit-game.ru")
+
+	pwaEmail := "pwa-login-" + uuid.NewString() + "@example.com"
+	if _, err := svc.RequestLoginCode(ctx, pwaEmail, "", "en", true); err != nil {
+		t.Fatalf("pwa request login: %v", err)
+	}
+	if sixDigit.FindString(mailer.lastBody) == "" {
+		t.Errorf("pwa login mail must still carry the code, body %q", mailer.lastBody)
+	}
+	if confirmToken.MatchString(mailer.lastBody) {
+		t.Errorf("pwa login mail must omit the one-tap confirm link, body %q", mailer.lastBody)
+	}
+
+	webEmail := "web-login-" + uuid.NewString() + "@example.com"
+	if _, err := svc.RequestLoginCode(ctx, webEmail, "", "en", false); err != nil {
+		t.Fatalf("web request login: %v", err)
+	}
+	if !confirmToken.MatchString(mailer.lastBody) {
+		t.Errorf("non-pwa login mail must keep the one-tap confirm link, body %q", mailer.lastBody)
+	}
+}
+
+// confirmToken extracts the one-tap deeplink token from the /app/#/confirm/<token> link
+// the branded email carries.
+var confirmToken = regexp.MustCompile(`/confirm/([A-Za-z0-9_-]+)`)
+
+func tokenFromMail(t *testing.T, body string) string {
+	t.Helper()
+	m := confirmToken.FindStringSubmatch(body)
+	if m == nil {
+		t.Fatalf("no confirm token in mail body %q", body)
+	}
+	return m[1]
+}
+
+// TestConfirmByTokenLogin: the one-tap deeplink token completes an email login,
+// clearing the guest flag.
+func TestConfirmByTokenLogin(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	mailer := &capturingMailer{}
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
+	email := "tok-login-" + uuid.NewString() + "@example.com"
+
+	id, err := svc.RequestLoginCode(ctx, email, "", "en", false)
+	if err != nil {
+		t.Fatalf("request login: %v", err)
+	}
+	res, err := svc.ConfirmByToken(ctx, tokenFromMail(t, mailer.lastBody))
+	if err != nil {
+		t.Fatalf("confirm by token: %v", err)
+	}
+	if !res.IsLogin() || res.Account != id {
+		t.Fatalf("login result = %+v, want login for %s", res, id)
+	}
+	if !identityConfirmed(t, account.KindEmail, email) {
+		t.Error("email identity must be confirmed after the token login")
+	}
+	if acc, _ := store.GetByID(ctx, id); acc.IsGuest {
+		t.Error("the token login must clear the guest flag")
+	}
+}
+
+// TestConfirmByTokenLink: the token attaches a free email to the requesting account.
+func TestConfirmByTokenLink(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	mailer := &capturingMailer{}
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
+	acc := provisionAccount(t)
+	email := "tok-link-" + uuid.NewString() + "@example.com"
+
+	if err := svc.RequestLinkCode(ctx, acc, email); err != nil {
+		t.Fatalf("request link: %v", err)
+	}
+	res, err := svc.ConfirmByToken(ctx, tokenFromMail(t, mailer.lastBody))
+	if err != nil {
+		t.Fatalf("confirm by token: %v", err)
+	}
+	if res.IsLogin() || res.NeedsMerge || res.Account != acc {
+		t.Fatalf("link result = %+v, want a plain link for %s", res, acc)
+	}
+	if !identityConfirmed(t, account.KindEmail, email) {
+		t.Error("email identity must be confirmed after the token link")
+	}
+}
+
+// TestConfirmByTokenLinkMerge: a token for an address owned by another account signals
+// a merge (leaving the token unconsumed for the interactive step).
+func TestConfirmByTokenLinkMerge(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	mailer := &capturingMailer{}
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
+	email := "tok-merge-" + uuid.NewString() + "@example.com"
+
+	owner := provisionAccount(t)
+	if err := svc.RequestCode(ctx, owner, email); err != nil {
+		t.Fatalf("owner request: %v", err)
+	}
+	if _, err := svc.ConfirmCode(ctx, owner, email, sixDigit.FindString(mailer.lastBody)); err != nil {
+		t.Fatalf("owner confirm: %v", err)
+	}
+
+	other := provisionAccount(t)
+	if err := svc.RequestLinkCode(ctx, other, email); err != nil {
+		t.Fatalf("link request: %v", err)
+	}
+	res, err := svc.ConfirmByToken(ctx, tokenFromMail(t, mailer.lastBody))
+	if err != nil {
+		t.Fatalf("confirm by token: %v", err)
+	}
+	if !res.NeedsMerge || res.MergeOwner != owner {
+		t.Fatalf("merge result = %+v, want NeedsMerge with owner=%s", res, owner)
+	}
+}
+
+// TestEmailAccountSeedsDisplayName seeds a new email account's display name from the
+// email's local part, so an email login is not left nameless.
+func TestEmailAccountSeedsDisplayName(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	svc := account.NewEmailService(store, &capturingMailer{}, "https://erudit-game.ru")
+	local := "kaya-" + uuid.NewString()[:8]
+
+	id, err := svc.RequestLoginCode(ctx, local+"@example.com", "", "en", false)
+	if err != nil {
+		t.Fatalf("request login: %v", err)
+	}
+	acc, err := store.GetByID(ctx, id)
+	if err != nil {
+		t.Fatalf("get: %v", err)
+	}
+	if acc.DisplayName != local {
+		t.Errorf("display name = %q, want the email local part %q", acc.DisplayName, local)
+	}
+}
+
+// TestConfirmByTokenLinkClearsGuest: binding an email to a guest via the deeplink
+// promotes the guest to a durable account (the deeplink path must match the
+// code-based link flow, which clears the guest flag).
+func TestConfirmByTokenLinkClearsGuest(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	mailer := &capturingMailer{}
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
+	guest, err := store.ProvisionGuest(ctx, "")
+	if err != nil {
+		t.Fatalf("provision guest: %v", err)
+	}
+	email := "guest-link-" + uuid.NewString() + "@example.com"
+
+	if err := svc.RequestLinkCode(ctx, guest.ID, email); err != nil {
+		t.Fatalf("request link: %v", err)
+	}
+	if _, err := svc.ConfirmByToken(ctx, tokenFromMail(t, mailer.lastBody)); err != nil {
+		t.Fatalf("confirm by token: %v", err)
+	}
+	acc, err := store.GetByID(ctx, guest.ID)
+	if err != nil {
+		t.Fatalf("get: %v", err)
+	}
+	if acc.IsGuest {
+		t.Error("linking an email via the deeplink must promote the guest to durable")
+	}
+}

backend/internal/inttest/game_test.go

@@ -14,6 +14,8 @@ import (
 	"scrabble/backend/internal/account"
 	"scrabble/backend/internal/engine"
 	"scrabble/backend/internal/game"
+	"scrabble/backend/internal/payments"
+	"scrabble/backend/internal/session"
 )
 
 // TestListForAccount checks the lobby "my games" query: it returns exactly the
@@ -401,8 +403,13 @@ func gameStatus(t *testing.T, svc *game.Service, id uuid.UUID) (status, endReaso
 // TestHintPolicy exercises the per-game allowance, the profile wallet and the
 // disabled switch.
 func TestHintPolicy(t *testing.T) {
-	ctx := context.Background()
+	// A trusted platform context so the online hint wallet (payments) is reachable; a provisioned
+	// account carries a telegram identity, so the telegram origin is the applicable one here.
+	ctx := session.WithPlatform(context.Background(),
+		session.Platform{Kind: session.PlatformKindTelegram, Subtype: session.SubtypeAndroid})
 	svc := newGameService()
+	pay := newPaymentsService()
+	svc.SetHintWallet(pay) // share the handle so a grant invalidates the wallet the game reads
 	seats := []uuid.UUID{provisionAccount(t), provisionAccount(t)}
 	seed := openingSeed(t)
 	g, err := svc.Create(ctx, game.CreateParams{
@@ -428,7 +435,11 @@ func TestHintPolicy(t *testing.T) {
 	if _, err := svc.Hint(ctx, g.ID, seats[0]); !errors.Is(err, game.ErrNoHintsLeft) {
 		t.Fatalf("second hint = %v, want ErrNoHintsLeft", err)
 	}
-	setHintBalance(t, seats[0], 2)
+	// Grant 2 hints on the telegram origin through the service so its read cache is invalidated
+	// (a raw insert would leave the cache warmed at zero by the allowance hint above).
+	if err := pay.Grant(ctx, seats[0], payments.SourceTelegram, 2, 0, false); err != nil {
+		t.Fatalf("grant hints: %v", err)
+	}
 	res, err := svc.Hint(ctx, g.ID, seats[0]) // spends the wallet
 	if err != nil {
 		t.Fatalf("wallet hint: %v", err)
@@ -603,14 +614,6 @@ func setAway(t *testing.T, id uuid.UUID, tz, start, end string) {
 	}
 }
 
-func setHintBalance(t *testing.T, id uuid.UUID, n int) {
-	t.Helper()
-	if _, err := testDB.ExecContext(context.Background(),
-		`UPDATE backend.accounts SET hint_balance = $1 WHERE account_id = $2`, n, id); err != nil {
-		t.Fatalf("set hint balance: %v", err)
-	}
-}
-
 func equalStrings(a, b []string) bool {
 	if len(a) != len(b) {
 		return false

backend/internal/inttest/helpers.go

@@ -17,6 +17,7 @@ import (
 	"scrabble/backend/internal/engine"
 	"scrabble/backend/internal/game"
 	"scrabble/backend/internal/lobby"
+	"scrabble/backend/internal/payments"
 	"scrabble/backend/internal/robot"
 	"scrabble/backend/internal/social"
 )
@@ -42,9 +43,42 @@ func newGameService() *game.Service {
 		zap.NewNop(),
 	)
 	svc.SetFirstMoveEntropy(seatZeroFirstMove)
+	svc.SetHintWallet(newPaymentsService())
 	return svc
 }
 
+// newPaymentsService builds a payments service over the shared pool (its own in-process read
+// cache), for wiring the game hint wallet and the account-merge fold in the integration suite.
+func newPaymentsService() *payments.Service {
+	return payments.NewService(payments.NewStore(testDB))
+}
+
+// seedBenefit writes a payments benefit row for an account+origin directly (bypassing the
+// service), used to stand up wallet state a test then spends or merges. A non-zero hints count
+// and/or the forever flag are set; a caller wanting a no-ads term sets it via seedBenefitUntil.
+func seedBenefit(t *testing.T, id uuid.UUID, origin string, hints int, forever bool) {
+	t.Helper()
+	if _, err := testDB.ExecContext(context.Background(),
+		`INSERT INTO payments.benefits (account_id, origin, hints, ads_forever) VALUES ($1,$2,$3,$4)
+		 ON CONFLICT (account_id, origin) DO UPDATE SET hints = EXCLUDED.hints, ads_forever = EXCLUDED.ads_forever`,
+		id, origin, hints, forever); err != nil {
+		t.Fatalf("seed benefit: %v", err)
+	}
+}
+
+// readBenefit reads an account's benefit row for an origin: the hint count and the forever flag
+// (both zero/false when the row is absent).
+func readBenefit(t *testing.T, id uuid.UUID, origin string) (hints int, forever bool) {
+	t.Helper()
+	err := testDB.QueryRowContext(context.Background(),
+		`SELECT hints, ads_forever FROM payments.benefits WHERE account_id=$1 AND origin=$2`, id, origin).
+		Scan(&hints, &forever)
+	if err != nil && !errors.Is(err, sql.ErrNoRows) {
+		t.Fatalf("read benefit: %v", err)
+	}
+	return hints, forever
+}
+
 // seatZeroFirstMove is a first-move-draw entropy factory that always elects the first
 // listed account as the leader, keeping the integration suite's turn order stable
 // despite the real draw's randomness: the first contender draws a blank — the best

backend/internal/inttest/link_change_test.go

@@ -0,0 +1,174 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/account"
+)
+
+// emailOf returns the external id of the account's email identity, or "" when it has none.
+func emailOf(t *testing.T, store *account.Store, id uuid.UUID) string {
+	t.Helper()
+	ids, err := store.Identities(context.Background(), id)
+	if err != nil {
+		t.Fatalf("identities %s: %v", id, err)
+	}
+	for _, i := range ids {
+		if i.Kind == account.KindEmail {
+			return i.ExternalID
+		}
+	}
+	return ""
+}
+
+// TestUnlinkProviderKeepsOthers detaches one provider from a multi-identity account and
+// refuses to remove the last remaining identity.
+func TestUnlinkProviderKeepsOthers(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+
+	acc, err := store.ProvisionByIdentity(ctx, account.KindTelegram, "tg-"+uuid.NewString())
+	if err != nil {
+		t.Fatalf("provision telegram: %v", err)
+	}
+	email := "unlink-" + uuid.NewString() + "@example.com"
+	if err := store.AttachIdentity(ctx, acc.ID, account.KindEmail, email, true); err != nil {
+		t.Fatalf("attach email: %v", err)
+	}
+
+	// Removing a kind the account does not hold reports not-found.
+	if err := store.RemoveIdentity(ctx, acc.ID, account.KindVK); !errors.Is(err, account.ErrNotFound) {
+		t.Fatalf("remove absent vk = %v, want ErrNotFound", err)
+	}
+
+	// Detach Telegram: the email identity remains.
+	if err := store.RemoveIdentity(ctx, acc.ID, account.KindTelegram); err != nil {
+		t.Fatalf("remove telegram: %v", err)
+	}
+	ids, err := store.Identities(ctx, acc.ID)
+	if err != nil {
+		t.Fatalf("identities: %v", err)
+	}
+	if len(ids) != 1 || ids[0].Kind != account.KindEmail {
+		t.Fatalf("identities after unlink = %+v, want only email", ids)
+	}
+
+	// The email is now the last identity, so unlinking it is refused.
+	if err := store.RemoveIdentity(ctx, acc.ID, account.KindEmail); !errors.Is(err, account.ErrLastIdentity) {
+		t.Fatalf("remove last email = %v, want ErrLastIdentity", err)
+	}
+}
+
+// TestChangeEmailReplaces switches an account's confirmed email to a free address,
+// freeing the old one.
+func TestChangeEmailReplaces(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	mailer := &capturingMailer{}
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
+
+	acc, err := store.ProvisionByIdentity(ctx, account.KindTelegram, "tg-"+uuid.NewString())
+	if err != nil {
+		t.Fatalf("provision: %v", err)
+	}
+	oldAddr := "old-" + uuid.NewString() + "@example.com"
+	if err := store.AttachIdentity(ctx, acc.ID, account.KindEmail, oldAddr, true); err != nil {
+		t.Fatalf("attach old email: %v", err)
+	}
+	newAddr := "new-" + uuid.NewString() + "@example.com"
+
+	if err := svc.RequestChangeCode(ctx, acc.ID, newAddr); err != nil {
+		t.Fatalf("request change: %v", err)
+	}
+	code := sixDigit.FindString(mailer.lastBody)
+	if _, err := svc.ConfirmChange(ctx, acc.ID, newAddr, code); err != nil {
+		t.Fatalf("confirm change: %v", err)
+	}
+	if got := emailOf(t, store, acc.ID); got != newAddr {
+		t.Fatalf("email after change = %q, want %q", got, newAddr)
+	}
+	if !identityConfirmed(t, account.KindEmail, newAddr) {
+		t.Error("the new email identity must be confirmed")
+	}
+	// The old address is freed: another account can now claim it.
+	other, err := store.ProvisionByIdentity(ctx, account.KindTelegram, "tg-"+uuid.NewString())
+	if err != nil {
+		t.Fatalf("provision other: %v", err)
+	}
+	if err := store.AttachIdentity(ctx, other.ID, account.KindEmail, oldAddr, true); err != nil {
+		t.Fatalf("old address should be free after change, got: %v", err)
+	}
+}
+
+// TestChangeEmailRefusesTaken refuses (without merging) a new address already confirmed by
+// another account, leaving the caller's email untouched.
+func TestChangeEmailRefusesTaken(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	mailer := &capturingMailer{}
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
+
+	acc, err := store.ProvisionByIdentity(ctx, account.KindTelegram, "tg-"+uuid.NewString())
+	if err != nil {
+		t.Fatalf("provision caller: %v", err)
+	}
+	mine := "mine-" + uuid.NewString() + "@example.com"
+	if err := store.AttachIdentity(ctx, acc.ID, account.KindEmail, mine, true); err != nil {
+		t.Fatalf("attach caller email: %v", err)
+	}
+	other, err := store.ProvisionByIdentity(ctx, account.KindTelegram, "tg-"+uuid.NewString())
+	if err != nil {
+		t.Fatalf("provision other: %v", err)
+	}
+	taken := "taken-" + uuid.NewString() + "@example.com"
+	if err := store.AttachIdentity(ctx, other.ID, account.KindEmail, taken, true); err != nil {
+		t.Fatalf("attach other email: %v", err)
+	}
+
+	if err := svc.RequestChangeCode(ctx, acc.ID, taken); err != nil {
+		t.Fatalf("request change: %v", err)
+	}
+	code := sixDigit.FindString(mailer.lastBody)
+	if _, err := svc.ConfirmChange(ctx, acc.ID, taken, code); !errors.Is(err, account.ErrEmailTaken) {
+		t.Fatalf("confirm change to taken = %v, want ErrEmailTaken", err)
+	}
+	if got := emailOf(t, store, acc.ID); got != mine {
+		t.Errorf("caller email after refused change = %q, want unchanged %q", got, mine)
+	}
+}
+
+// TestChangeEmailViaDeeplink switches the email through the one-tap confirm token.
+func TestChangeEmailViaDeeplink(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	mailer := &capturingMailer{}
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
+
+	acc, err := store.ProvisionByIdentity(ctx, account.KindTelegram, "tg-"+uuid.NewString())
+	if err != nil {
+		t.Fatalf("provision: %v", err)
+	}
+	if err := store.AttachIdentity(ctx, acc.ID, account.KindEmail, "old-"+uuid.NewString()+"@example.com", true); err != nil {
+		t.Fatalf("attach old email: %v", err)
+	}
+	newAddr := "dl-" + uuid.NewString() + "@example.com"
+	if err := svc.RequestChangeCode(ctx, acc.ID, newAddr); err != nil {
+		t.Fatalf("request change: %v", err)
+	}
+	res, err := svc.ConfirmByToken(ctx, tokenFromMail(t, mailer.lastBody))
+	if err != nil {
+		t.Fatalf("confirm by token: %v", err)
+	}
+	if res.IsLogin() || res.NeedsMerge || res.Account != acc.ID {
+		t.Fatalf("deeplink change result = %+v, want a plain change for %s", res, acc.ID)
+	}
+	if got := emailOf(t, store, acc.ID); got != newAddr {
+		t.Fatalf("email after deeplink change = %q, want %q", got, newAddr)
+	}
+}

backend/internal/inttest/merge_test.go

@@ -58,14 +58,6 @@ func bestMoveCount(t *testing.T, id uuid.UUID) int {
 	return n
 }
 
-func setWallet(t *testing.T, id uuid.UUID, hints int, paid bool) {
-	t.Helper()
-	if _, err := testDB.ExecContext(context.Background(),
-		`UPDATE backend.accounts SET hint_balance=$2, paid_account=$3 WHERE account_id=$1`, id, hints, paid); err != nil {
-		t.Fatalf("set wallet: %v", err)
-	}
-}
-
 func bindEmailIdentity(t *testing.T, acc uuid.UUID, email string) {
 	t.Helper()
 	if _, err := testDB.ExecContext(context.Background(),
@@ -119,7 +111,7 @@ func seatGame(t *testing.T, seats []uuid.UUID, timeout time.Duration) uuid.UUID
 
 func newLinkService(mailer account.Mailer) *link.Service {
 	store := account.NewStore(testDB)
-	emails := account.NewEmailService(store, mailer)
+	emails := account.NewEmailService(store, mailer, "https://erudit-game.ru")
 	sessions := session.NewService(session.NewStore(testDB), session.NewCache())
 	return link.NewService(emails, store, accountmerge.NewMerger(testDB), sessions)
 }
@@ -131,6 +123,7 @@ func TestAccountMergeCore(t *testing.T) {
 	ctx := context.Background()
 	store := account.NewStore(testDB)
 	merger := accountmerge.NewMerger(testDB)
+	merger.SetPayments(newPaymentsService())
 
 	primary := provisionAccount(t)
 	secondary := provisionAccount(t)
@@ -140,8 +133,8 @@ func TestAccountMergeCore(t *testing.T) {
 	setStats(t, secondary, 3, 1, 2, 400, 80)
 	setStatsCounts(t, primary, 100, 5)
 	setStatsCounts(t, secondary, 50, 8)
-	setWallet(t, primary, 2, false)
-	setWallet(t, secondary, 5, true)
+	seedBenefit(t, primary, "telegram", 2, false)
+	seedBenefit(t, secondary, "telegram", 5, true) // hints sum, forever OR-s on merge
 	// Best moves: secondary's scrabble_en (80) beats primary's (50) and is kept; secondary's
 	// scrabble_ru (30) is new to primary and carried over.
 	setBestMove(t, primary, "scrabble_en", 50)
@@ -165,15 +158,13 @@ func TestAccountMergeCore(t *testing.T) {
 		t.Error("secondary stats row should be deleted after merge")
 	}
 
-	acc, err := store.GetByID(ctx, primary)
-	if err != nil {
-		t.Fatalf("get primary: %v", err)
+	// The payments wallet merged by origin: hints sum (2+5) and the forever flag OR-s; the
+	// deprecated accounts.hint_balance / paid_account columns are no longer touched by a merge.
+	if hints, forever := readBenefit(t, primary, "telegram"); hints != 7 || !forever {
+		t.Errorf("merged telegram benefit = hints %d forever %v, want 7/true", hints, forever)
 	}
-	if acc.HintBalance != 7 {
-		t.Errorf("hint balance = %d, want 7", acc.HintBalance)
-	}
-	if !acc.PaidAccount {
-		t.Error("paid_account should be true (ORed from secondary)")
+	if hints, _ := readBenefit(t, secondary, "telegram"); hints != 0 {
+		t.Errorf("secondary benefit should be cleared after merge, got hints %d", hints)
 	}
 
 	if owner, ok, _ := store.AccountIDByIdentity(ctx, account.KindEmail, email); !ok || owner != primary {
@@ -251,6 +242,44 @@ func TestAccountMergeFinishedSharedGameKept(t *testing.T) {
 	}
 }
 
+// TestAccountMergeDedupesEmail keeps the primary's email when both accounts have one and
+// journals the secondary's to the dossier (reason=merge), so the survivor never ends up
+// with two email identities.
+func TestAccountMergeDedupesEmail(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	merger := accountmerge.NewMerger(testDB)
+
+	primary := provisionAccount(t)
+	secondary := provisionAccount(t)
+	primaryEmail := "keep-" + uuid.NewString() + "@example.com"
+	secondaryEmail := "absorb-" + uuid.NewString() + "@example.com"
+	bindEmailIdentity(t, primary, primaryEmail)
+	bindEmailIdentity(t, secondary, secondaryEmail)
+
+	if err := merger.Merge(ctx, primary, secondary); err != nil {
+		t.Fatalf("merge: %v", err)
+	}
+
+	// The primary keeps its own email; the secondary's is gone from the live identities.
+	if owner, ok, _ := store.AccountIDByIdentity(ctx, account.KindEmail, primaryEmail); !ok || owner != primary {
+		t.Errorf("primary email owner = %s ok=%v, want primary %s", owner, ok, primary)
+	}
+	if _, ok, _ := store.AccountIDByIdentity(ctx, account.KindEmail, secondaryEmail); ok {
+		t.Error("the secondary's email must be removed (no duplicate email on the survivor)")
+	}
+	// The absorbed email stays in the legal dossier, tagged reason=merge.
+	var reason string
+	if err := testDB.QueryRowContext(ctx,
+		`SELECT reason FROM backend.retained_identities WHERE account_id=$1 AND kind='email' AND external_id=$2`,
+		secondary, secondaryEmail).Scan(&reason); err != nil {
+		t.Fatalf("retained email row: %v", err)
+	}
+	if reason != "merge" {
+		t.Errorf("retained reason = %q, want merge", reason)
+	}
+}
+
 // TestAccountLinkFreeEmail binds a free email and promotes a guest to durable.
 func TestAccountLinkFreeEmail(t *testing.T) {
 	ctx := context.Background()
@@ -355,3 +384,64 @@ func TestAccountLinkGuestInversion(t *testing.T) {
 		t.Errorf("email owner = %s, want durable", owner)
 	}
 }
+
+// TestAccountLinkFreeVK binds a free VK identity (gateway-validated, no code) and
+// promotes a guest to durable — the ConfirmVK counterpart of the free-email case.
+func TestAccountLinkFreeVK(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	links := newLinkService(&capturingMailer{})
+
+	guest := provisionGuest(t)
+	vkID := "vk-" + uuid.NewString()
+	res, err := links.ConfirmVK(ctx, guest, vkID)
+	if err != nil {
+		t.Fatalf("confirm vk: %v", err)
+	}
+	if !res.Linked || res.MergeRequired {
+		t.Fatalf("confirm = %+v, want linked", res)
+	}
+	if acc, _ := store.GetByID(ctx, guest); acc.IsGuest {
+		t.Error("guest flag should clear once VK is linked")
+	}
+	if owner, ok, _ := store.AccountIDByIdentity(ctx, account.KindVK, vkID); !ok || owner != guest {
+		t.Errorf("vk owner = %s, want the promoted guest %s", owner, guest)
+	}
+}
+
+// TestAccountLinkVKMergeIntoCaller merges the account owning a VK identity into the
+// current durable account: ConfirmVK previews the merge, MergeVK folds it, the caller
+// stays primary and keeps its session, and the VK identity repoints to the caller.
+func TestAccountLinkVKMergeIntoCaller(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	links := newLinkService(&capturingMailer{})
+
+	caller := provisionAccount(t)
+	other := provisionAccount(t)
+	vkID := "vk-" + uuid.NewString()
+	if err := store.AttachIdentity(ctx, other, account.KindVK, vkID, true); err != nil {
+		t.Fatalf("seed vk on other: %v", err)
+	}
+
+	confirm, err := links.ConfirmVK(ctx, caller, vkID)
+	if err != nil {
+		t.Fatalf("confirm vk: %v", err)
+	}
+	if !confirm.MergeRequired || confirm.SecondaryID != other {
+		t.Fatalf("confirm = %+v, want merge_required to other %s", confirm, other)
+	}
+	merge, err := links.MergeVK(ctx, caller, vkID)
+	if err != nil {
+		t.Fatalf("merge vk: %v", err)
+	}
+	if merge.PrimaryID != caller || merge.SwitchedToken != "" {
+		t.Fatalf("merge = %+v, want primary caller and no session switch", merge)
+	}
+	if mergedInto(t, other) != caller {
+		t.Error("other should be tombstoned into caller")
+	}
+	if owner, _, _ := store.AccountIDByIdentity(ctx, account.KindVK, vkID); owner != caller {
+		t.Errorf("vk owner = %s, want caller after merge", owner)
+	}
+}

backend/internal/inttest/payments_catalog_test.go

@@ -0,0 +1,113 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"testing"
+
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/payments"
+)
+
+// methodPrice is one per-method money price for a seeded chip pack.
+type methodPrice struct {
+	method   string
+	currency string
+	amount   int64
+}
+
+// seedPackProduct creates an active chip pack: a product carrying the chips atom and a money price
+// per method. It returns the product id.
+func seedPackProduct(t *testing.T, chips int, prices ...methodPrice) uuid.UUID {
+	t.Helper()
+	ctx := context.Background()
+	prod := uuid.New()
+	if _, err := testDB.ExecContext(ctx,
+		`INSERT INTO payments.product (product_id, title, active) VALUES ($1,'test pack',true)`, prod); err != nil {
+		t.Fatalf("seed pack product: %v", err)
+	}
+	if _, err := testDB.ExecContext(ctx,
+		`INSERT INTO payments.product_item (product_id, atom_type, quantity) VALUES ($1,'chips',$2)`, prod, chips); err != nil {
+		t.Fatalf("seed chips item: %v", err)
+	}
+	for _, p := range prices {
+		if _, err := testDB.ExecContext(ctx,
+			`INSERT INTO payments.product_price (product_id, method, currency, amount) VALUES ($1,$2,$3,$4)`,
+			prod, p.method, p.currency, p.amount); err != nil {
+			t.Fatalf("seed pack price %s: %v", p.method, err)
+		}
+	}
+	return prod
+}
+
+// findCatalogProduct returns the projected storefront product for id in the context (the catalog
+// is global, so tests assert by id rather than count — testDB is shared).
+func findCatalogProduct(t *testing.T, svc *payments.Service, cxt payments.Context, id uuid.UUID) (payments.CatalogProduct, bool) {
+	t.Helper()
+	view, err := svc.Catalog(context.Background(), cxt)
+	if err != nil {
+		t.Fatalf("catalog: %v", err)
+	}
+	for _, p := range view.Products {
+		if p.ProductID == id.String() {
+			return p, true
+		}
+	}
+	return payments.CatalogProduct{}, false
+}
+
+// TestPaymentsCatalogByContext verifies the storefront projects a value at its chip price in every
+// context and a chip pack at the context method's money price, over Postgres.
+func TestPaymentsCatalogByContext(t *testing.T) {
+	svc := newPaymentsService()
+	value := seedValueProduct(t, 500, 250, 0)
+	pack := seedPackProduct(t, 100,
+		methodPrice{"vk", "VOTE", 20},
+		methodPrice{"telegram", "XTR", 25},
+		methodPrice{"direct", "RUB", 14900},
+	)
+
+	for _, kind := range []string{"vk", "telegram", "direct"} {
+		v, ok := findCatalogProduct(t, svc, payments.NewContext(kind, "web"), value)
+		if !ok {
+			t.Fatalf("value missing in %s context", kind)
+		}
+		if v.Kind != "value" || v.Chips != 500 || v.MoneyCurrency != "" {
+			t.Errorf("value in %s = %+v, want kind=value chips=500 no money", kind, v)
+		}
+	}
+
+	cases := []struct {
+		kind     string
+		amount   int64
+		currency string
+	}{
+		{"vk", 20, "VOTE"},
+		{"telegram", 25, "XTR"},
+		{"direct", 14900, "RUB"},
+	}
+	for _, tc := range cases {
+		p, ok := findCatalogProduct(t, svc, payments.NewContext(tc.kind, "web"), pack)
+		if !ok {
+			t.Fatalf("pack missing in %s context", tc.kind)
+		}
+		if p.Kind != "pack" || p.Chips != 0 || p.MoneyAmount != tc.amount || p.MoneyCurrency != tc.currency {
+			t.Errorf("pack in %s = %+v, want kind=pack amount=%d currency=%s", tc.kind, p, tc.amount, tc.currency)
+		}
+	}
+}
+
+// TestPaymentsCatalogExcludesDeactivated verifies a soft-deleted product drops out of the storefront.
+func TestPaymentsCatalogExcludesDeactivated(t *testing.T) {
+	svc := newPaymentsService()
+	prod := seedValueProduct(t, 100, 10, 0)
+	if _, err := testDB.ExecContext(context.Background(),
+		`UPDATE payments.product SET active=false WHERE product_id=$1`, prod); err != nil {
+		t.Fatalf("deactivate: %v", err)
+	}
+	if _, ok := findCatalogProduct(t, svc, payments.NewContext("direct", "web"), prod); ok {
+		t.Error("deactivated product must not appear in the storefront")
+	}
+}

backend/internal/inttest/payments_test.go

@@ -0,0 +1,263 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5/pgconn"
+	"github.com/pressly/goose/v3"
+	testcontainers "github.com/testcontainers/testcontainers-go"
+	tcpostgres "github.com/testcontainers/testcontainers-go/modules/postgres"
+	"github.com/testcontainers/testcontainers-go/wait"
+
+	"scrabble/backend/internal/postgres"
+	"scrabble/backend/internal/postgres/migrations"
+)
+
+// isPgCode reports whether err is a PostgreSQL server error with the given
+// SQLSTATE code.
+func isPgCode(err error, code string) bool {
+	var pgErr *pgconn.PgError
+	return errors.As(err, &pgErr) && pgErr.Code == code
+}
+
+// TestPaymentsSchemaAndSeeds checks the payments schema, its role and the fixed
+// seed rows are present after migration.
+func TestPaymentsSchemaAndSeeds(t *testing.T) {
+	ctx := context.Background()
+
+	var atoms int
+	if err := testDB.QueryRowContext(ctx, "SELECT count(*) FROM payments.catalog_atom").Scan(&atoms); err != nil {
+		t.Fatalf("count catalog_atom: %v", err)
+	}
+	if atoms != 4 {
+		t.Errorf("catalog_atom rows = %d, want 4 (chips/hints/noads_days/tournament)", atoms)
+	}
+
+	var cfg int
+	if err := testDB.QueryRowContext(ctx, "SELECT count(*) FROM payments.config").Scan(&cfg); err != nil {
+		t.Fatalf("count config: %v", err)
+	}
+	if cfg != 1 {
+		t.Errorf("config rows = %d, want the single seeded row", cfg)
+	}
+
+	var roleExists bool
+	if err := testDB.QueryRowContext(ctx, "SELECT EXISTS(SELECT 1 FROM pg_roles WHERE rolname = 'payments')").Scan(&roleExists); err != nil {
+		t.Fatalf("check payments role: %v", err)
+	}
+	if !roleExists {
+		t.Error("payments role missing")
+	}
+}
+
+// TestPaymentsRoleConfinement proves the payments role is confined to its own
+// schema: it can read payments.* but is denied on backend.*. The application
+// itself connects as a superuser (which bypasses this), so this asserts the
+// grants are correct as the stepping-stone to a real separate login; the runtime
+// wall for the superuser pool is the import-boundary test in the payments package.
+func TestPaymentsRoleConfinement(t *testing.T) {
+	ctx := context.Background()
+	tx, err := testDB.BeginTx(ctx, nil)
+	if err != nil {
+		t.Fatalf("begin tx: %v", err)
+	}
+	defer func() { _ = tx.Rollback() }()
+
+	if _, err := tx.ExecContext(ctx, "SET LOCAL ROLE payments"); err != nil {
+		t.Fatalf("SET LOCAL ROLE payments: %v", err)
+	}
+
+	// The payments role can read its own schema.
+	var n int
+	if err := tx.QueryRowContext(ctx, "SELECT count(*) FROM payments.config").Scan(&n); err != nil {
+		t.Errorf("payments role denied on payments.config (grants wrong): %v", err)
+	}
+
+	// The payments role must NOT reach the backend schema.
+	err = tx.QueryRowContext(ctx, "SELECT count(*) FROM backend.accounts").Scan(&n)
+	if err == nil {
+		t.Fatal("payments role could read backend.accounts — cross-schema isolation broken")
+	}
+	if !isPgCode(err, "42501") {
+		t.Errorf("reading backend.accounts as payments: got %v, want permission-denied (42501)", err)
+	}
+}
+
+// TestPaymentsLedgerAppendOnly verifies the append-only trigger rejects any
+// UPDATE or DELETE on the ledger (a superuser is bound by the trigger, unlike a
+// mere privilege REVOKE).
+func TestPaymentsLedgerAppendOnly(t *testing.T) {
+	ctx := context.Background()
+	id := uuid.New()
+	if _, err := testDB.ExecContext(ctx,
+		`INSERT INTO payments.ledger (ledger_id, account_id, kind, chips_delta) VALUES ($1, $2, 'admin_grant', 0)`,
+		id, uuid.New()); err != nil {
+		t.Fatalf("insert ledger row: %v", err)
+	}
+
+	if _, err := testDB.ExecContext(ctx, `UPDATE payments.ledger SET chips_delta = 1 WHERE ledger_id = $1`, id); err == nil {
+		t.Error("UPDATE on payments.ledger succeeded — append-only violated")
+	} else if !isPgCode(err, "P0001") {
+		t.Errorf("UPDATE ledger: got %v, want the append-only exception (P0001)", err)
+	}
+
+	if _, err := testDB.ExecContext(ctx, `DELETE FROM payments.ledger WHERE ledger_id = $1`, id); err == nil {
+		t.Error("DELETE on payments.ledger succeeded — append-only violated")
+	} else if !isPgCode(err, "P0001") {
+		t.Errorf("DELETE ledger: got %v, want the append-only exception (P0001)", err)
+	}
+}
+
+// TestPaymentsCheckConstraints verifies the domain CHECKs bite: non-negative
+// balances/hints/amount and the enum-like columns.
+func TestPaymentsCheckConstraints(t *testing.T) {
+	ctx := context.Background()
+
+	prod := uuid.New()
+	if _, err := testDB.ExecContext(ctx, `INSERT INTO payments.product (product_id, title) VALUES ($1, 'test')`, prod); err != nil {
+		t.Fatalf("insert product: %v", err)
+	}
+
+	cases := []struct {
+		name string
+		sql  string
+		args []any
+	}{
+		{"balances chips negative", `INSERT INTO payments.balances (account_id, source, chips) VALUES ($1, 'vk', -1)`, []any{uuid.New()}},
+		{"balances bad source", `INSERT INTO payments.balances (account_id, source, chips) VALUES ($1, 'nope', 0)`, []any{uuid.New()}},
+		{"benefits hints negative", `INSERT INTO payments.benefits (account_id, origin, hints) VALUES ($1, 'vk', -1)`, []any{uuid.New()}},
+		{"ledger bad kind", `INSERT INTO payments.ledger (ledger_id, account_id, kind) VALUES ($1, $2, 'bogus')`, []any{uuid.New(), uuid.New()}},
+		{"product_price amount negative", `INSERT INTO payments.product_price (product_id, method, currency, amount) VALUES ($1, 'direct', 'RUB', -1)`, []any{prod}},
+		{"product_price bad currency", `INSERT INTO payments.product_price (product_id, method, currency, amount) VALUES ($1, 'direct', 'EUR', 100)`, []any{prod}},
+	}
+	for _, c := range cases {
+		if _, err := testDB.ExecContext(ctx, c.sql, c.args...); err == nil {
+			t.Errorf("%s: insert succeeded, want a CHECK violation", c.name)
+		} else if !isPgCode(err, "23514") {
+			t.Errorf("%s: got %v, want check_violation (23514)", c.name, err)
+		}
+	}
+}
+
+// TestPaymentsLedgerIdempotencyIndex verifies the partial unique index makes a
+// (provider, provider_payment_id) pair collide once but leaves NULL-keyed rows
+// unconstrained.
+func TestPaymentsLedgerIdempotencyIndex(t *testing.T) {
+	ctx := context.Background()
+	insert := func(ppid *string) error {
+		_, err := testDB.ExecContext(ctx,
+			`INSERT INTO payments.ledger (ledger_id, account_id, kind, provider, provider_payment_id) VALUES ($1, $2, 'fund', 'robokassa', $3)`,
+			uuid.New(), uuid.New(), ppid)
+		return err
+	}
+
+	ppid := "inv-" + uuid.NewString()
+	if err := insert(&ppid); err != nil {
+		t.Fatalf("first insert: %v", err)
+	}
+	if err := insert(&ppid); err == nil {
+		t.Error("duplicate (provider, provider_payment_id) inserted — idempotency index missing")
+	} else if !isPgCode(err, "23505") {
+		t.Errorf("duplicate insert: got %v, want unique_violation (23505)", err)
+	}
+
+	// A NULL provider_payment_id is outside the partial index — repeats allowed.
+	if err := insert(nil); err != nil {
+		t.Fatalf("first null-ppid insert: %v", err)
+	}
+	if err := insert(nil); err != nil {
+		t.Errorf("second null-ppid insert should be allowed by the partial index: %v", err)
+	}
+}
+
+// TestPaymentsMigrationReversible proves the migration is expand-contract: it
+// applies, rolls fully back (schema, role, trigger and all), and re-applies
+// cleanly — so a backend image rollback stays DB-safe. It uses its own container
+// so the Down does not disturb the shared suite database.
+func TestPaymentsMigrationReversible(t *testing.T) {
+	ctx := context.Background()
+
+	container, err := tcpostgres.Run(ctx, pgImage,
+		tcpostgres.WithDatabase(pgDatabase),
+		tcpostgres.WithUsername(pgUser),
+		tcpostgres.WithPassword(pgPassword),
+		testcontainers.WithWaitStrategy(
+			wait.ForLog("database system is ready to accept connections").
+				WithOccurrence(2).
+				WithStartupTimeout(containerStartup),
+		),
+	)
+	if err != nil {
+		t.Fatalf("start container: %v", err)
+	}
+	defer func() { _ = container.Terminate(context.Background()) }()
+
+	baseDSN, err := container.ConnectionString(ctx, "sslmode=disable")
+	if err != nil {
+		t.Fatalf("connection string: %v", err)
+	}
+	dsn, err := withSearchPath(baseDSN, pgSchema)
+	if err != nil {
+		t.Fatalf("search path: %v", err)
+	}
+	cfg := postgres.DefaultConfig()
+	cfg.DSN = dsn
+	db, err := postgres.Open(ctx, cfg)
+	if err != nil {
+		t.Fatalf("open pool: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	// Up: apply every migration, including the payments foundation.
+	if err := postgres.ApplyMigrations(ctx, db); err != nil {
+		t.Fatalf("apply up: %v", err)
+	}
+	if !schemaExists(ctx, t, db, "payments") {
+		t.Fatal("payments schema absent after up")
+	}
+
+	// Down the payments migration and assert a clean teardown.
+	goose.SetBaseFS(migrations.Migrations())
+	defer goose.SetBaseFS(nil)
+	if err := goose.SetDialect("postgres"); err != nil {
+		t.Fatalf("set dialect: %v", err)
+	}
+	if err := goose.DownToContext(ctx, db, ".", 9); err != nil {
+		t.Fatalf("down to 9: %v", err)
+	}
+	if schemaExists(ctx, t, db, "payments") {
+		t.Error("payments schema survived the down migration")
+	}
+	var roleExists bool
+	if err := db.QueryRowContext(ctx, "SELECT EXISTS(SELECT 1 FROM pg_roles WHERE rolname = 'payments')").Scan(&roleExists); err != nil {
+		t.Fatalf("check role after down: %v", err)
+	}
+	if roleExists {
+		t.Error("payments role survived the down migration")
+	}
+
+	// Re-apply and assert it comes back cleanly.
+	if err := goose.UpContext(ctx, db, "."); err != nil {
+		t.Fatalf("re-apply up: %v", err)
+	}
+	if !schemaExists(ctx, t, db, "payments") {
+		t.Fatal("payments schema absent after re-apply")
+	}
+}
+
+// schemaExists reports whether a schema of the given name is present.
+func schemaExists(ctx context.Context, t *testing.T, db *sql.DB, name string) bool {
+	t.Helper()
+	var exists bool
+	if err := db.QueryRowContext(ctx,
+		"SELECT EXISTS(SELECT 1 FROM information_schema.schemata WHERE schema_name = $1)", name).Scan(&exists); err != nil {
+		t.Fatalf("check schema %s: %v", name, err)
+	}
+	return exists
+}

backend/internal/inttest/payments_wallet_test.go

@@ -0,0 +1,279 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/payments"
+)
+
+// seedBalance writes a chip balance for an account+source directly (payments has no FK to
+// accounts, so a bare uuid is a valid account id here).
+func seedBalance(t *testing.T, id uuid.UUID, source string, chips int) {
+	t.Helper()
+	if _, err := testDB.ExecContext(context.Background(),
+		`INSERT INTO payments.balances (account_id, source, chips) VALUES ($1,$2,$3)
+		 ON CONFLICT (account_id, source) DO UPDATE SET chips = EXCLUDED.chips`,
+		id, source, chips); err != nil {
+		t.Fatalf("seed balance: %v", err)
+	}
+}
+
+// readBalance reads an account's chip balance for a source (0 when the row is absent).
+func readBalance(t *testing.T, id uuid.UUID, source string) int {
+	t.Helper()
+	var chips int
+	err := testDB.QueryRowContext(context.Background(),
+		`SELECT chips FROM payments.balances WHERE account_id=$1 AND source=$2`, id, source).Scan(&chips)
+	if err != nil && !errors.Is(err, sql.ErrNoRows) {
+		t.Fatalf("read balance: %v", err)
+	}
+	return chips
+}
+
+// benefitUntil reads an account's no-ads term end for an origin (nil when none).
+func benefitUntil(t *testing.T, id uuid.UUID, origin string) *time.Time {
+	t.Helper()
+	var until *time.Time
+	err := testDB.QueryRowContext(context.Background(),
+		`SELECT ads_paid_until FROM payments.benefits WHERE account_id=$1 AND origin=$2`, id, origin).Scan(&until)
+	if err != nil && !errors.Is(err, sql.ErrNoRows) {
+		t.Fatalf("read benefit until: %v", err)
+	}
+	return until
+}
+
+// ledgerRows counts an account's ledger rows of a given kind.
+func ledgerRows(t *testing.T, id uuid.UUID, kind string) int {
+	t.Helper()
+	var n int
+	if err := testDB.QueryRowContext(context.Background(),
+		`SELECT count(*) FROM payments.ledger WHERE account_id=$1 AND kind=$2`, id, kind).Scan(&n); err != nil {
+		t.Fatalf("ledger count: %v", err)
+	}
+	return n
+}
+
+// seedValueProduct creates an active chip-priced value: a product with a CHIP price (method
+// NULL) and the given hint / no-ads-day atoms. It returns the product id.
+func seedValueProduct(t *testing.T, priceChips, hints, noAdsDays int) uuid.UUID {
+	t.Helper()
+	ctx := context.Background()
+	prod := uuid.New()
+	if _, err := testDB.ExecContext(ctx,
+		`INSERT INTO payments.product (product_id, title, active) VALUES ($1,'test value',true)`, prod); err != nil {
+		t.Fatalf("seed product: %v", err)
+	}
+	if _, err := testDB.ExecContext(ctx,
+		`INSERT INTO payments.product_price (product_id, method, currency, amount) VALUES ($1, NULL, 'CHIP', $2)`,
+		prod, priceChips); err != nil {
+		t.Fatalf("seed price: %v", err)
+	}
+	if hints > 0 {
+		if _, err := testDB.ExecContext(ctx,
+			`INSERT INTO payments.product_item (product_id, atom_type, quantity) VALUES ($1,'hints',$2)`, prod, hints); err != nil {
+			t.Fatalf("seed hints item: %v", err)
+		}
+	}
+	if noAdsDays > 0 {
+		if _, err := testDB.ExecContext(ctx,
+			`INSERT INTO payments.product_item (product_id, atom_type, quantity) VALUES ($1,'noads_days',$2)`, prod, noAdsDays); err != nil {
+			t.Fatalf("seed noads item: %v", err)
+		}
+	}
+	return prod
+}
+
+// TestPaymentsSpendAppliesAtomically verifies a chip spend writes the ledger row, decrements the
+// balance and applies the benefit together over Postgres.
+func TestPaymentsSpendAppliesAtomically(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	acc := uuid.New()
+	seedBalance(t, acc, "direct", 100)
+	prod := seedValueProduct(t, 60, 3, 30)
+
+	if err := svc.Spend(ctx, acc, payments.NewContext("direct", "web"), []payments.Source{payments.SourceDirect}, prod); err != nil {
+		t.Fatalf("spend: %v", err)
+	}
+	if got := readBalance(t, acc, "direct"); got != 40 {
+		t.Errorf("balance after spend = %d, want 40", got)
+	}
+	if hints, _ := readBenefit(t, acc, "direct"); hints != 3 {
+		t.Errorf("hints after spend = %d, want 3", hints)
+	}
+	if benefitUntil(t, acc, "direct") == nil {
+		t.Error("no-ads term not applied by the spend")
+	}
+	if n := ledgerRows(t, acc, "spend"); n != 1 {
+		t.Errorf("spend ledger rows = %d, want 1", n)
+	}
+}
+
+// TestPaymentsSpendInsufficientNoWrite verifies an under-funded spend is refused and writes
+// nothing (the balance, benefit and ledger are untouched).
+func TestPaymentsSpendInsufficientNoWrite(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	acc := uuid.New()
+	seedBalance(t, acc, "direct", 10)
+	prod := seedValueProduct(t, 60, 3, 0)
+
+	if err := svc.Spend(ctx, acc, payments.NewContext("direct", "web"), []payments.Source{payments.SourceDirect}, prod); !errors.Is(err, payments.ErrInsufficientChips) {
+		t.Fatalf("spend = %v, want ErrInsufficientChips", err)
+	}
+	if got := readBalance(t, acc, "direct"); got != 10 {
+		t.Errorf("balance changed to %d, want 10 (no write)", got)
+	}
+	if h, _ := readBenefit(t, acc, "direct"); h != 0 {
+		t.Errorf("benefit applied on a refused spend: hints %d", h)
+	}
+	if ledgerRows(t, acc, "spend") != 0 {
+		t.Error("spend ledger row written on a refused spend")
+	}
+}
+
+// TestPaymentsSpendGuardRollsBack forces the in-transaction guard to bite: with a stale read
+// cache the draw plan looks affordable, but the guarded decrement matches no row and the whole
+// transaction rolls back — no ledger row, no benefit, balance unchanged.
+func TestPaymentsSpendGuardRollsBack(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	acc := uuid.New()
+	seedBalance(t, acc, "direct", 100)
+	present := []payments.Source{payments.SourceDirect}
+	cxt := payments.NewContext("direct", "web")
+	if _, err := svc.Wallet(ctx, acc, cxt, present); err != nil { // warm the cache at 100
+		t.Fatalf("warm: %v", err)
+	}
+	// Drain the real balance behind the cache's back (no invalidation), so the plan over-commits.
+	if _, err := testDB.ExecContext(ctx, `UPDATE payments.balances SET chips = 10 WHERE account_id=$1 AND source='direct'`, acc); err != nil {
+		t.Fatalf("drain: %v", err)
+	}
+	prod := seedValueProduct(t, 60, 3, 0)
+
+	if err := svc.Spend(ctx, acc, cxt, present, prod); !errors.Is(err, payments.ErrInsufficientChips) {
+		t.Fatalf("spend = %v, want ErrInsufficientChips", err)
+	}
+	if got := readBalance(t, acc, "direct"); got != 10 {
+		t.Errorf("balance = %d, want 10 (rolled back)", got)
+	}
+	if ledgerRows(t, acc, "spend") != 0 {
+		t.Error("spend ledger row written despite the rollback")
+	}
+	if h, _ := readBenefit(t, acc, "direct"); h != 0 {
+		t.Error("benefit applied despite the rollback")
+	}
+}
+
+// TestPaymentsGrantCreditsValuesNotChips verifies admin_grant applies a benefit at price 0
+// without ever crediting chips (D16).
+func TestPaymentsGrantCreditsValuesNotChips(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	acc := uuid.New()
+
+	if err := svc.Grant(ctx, acc, payments.SourceDirect, 5, 0, true); err != nil {
+		t.Fatalf("grant: %v", err)
+	}
+	if hints, forever := readBenefit(t, acc, "direct"); hints != 5 || !forever {
+		t.Errorf("granted benefit = hints %d forever %v, want 5/true", hints, forever)
+	}
+	if readBalance(t, acc, "direct") != 0 {
+		t.Error("a grant must not credit chips")
+	}
+	if ledgerRows(t, acc, "admin_grant") != 1 {
+		t.Error("admin_grant ledger row missing")
+	}
+	if ledgerRows(t, acc, "spend") != 0 || ledgerRows(t, acc, "fund") != 0 {
+		t.Error("a grant wrote a non-grant ledger row")
+	}
+}
+
+// TestPaymentsSpendHintByContext verifies a hint is drawn from an applicable origin, and that a
+// direct-origin hint is not usable inside a VK context (the compliance wall for hints).
+func TestPaymentsSpendHintByContext(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	acc := uuid.New()
+	seedBenefit(t, acc, "direct", 2, false)
+	present := []payments.Source{payments.SourceDirect, payments.SourceVK}
+
+	if spent, err := svc.SpendHint(ctx, acc, payments.NewContext("direct", "web"), present); err != nil || !spent {
+		t.Fatalf("web spend hint = %v (err %v), want true", spent, err)
+	}
+	if h, _ := readBenefit(t, acc, "direct"); h != 1 {
+		t.Errorf("hints after spend = %d, want 1", h)
+	}
+	// Inside VK the applicable origins are {vk} only, so the direct-origin hint is untouched.
+	if spent, _ := svc.SpendHint(ctx, acc, payments.NewContext("vk", "android"), present); spent {
+		t.Error("direct-origin hint spent inside VK — compliance wall breached")
+	}
+	if h, _ := readBenefit(t, acc, "direct"); h != 1 {
+		t.Errorf("direct hints changed inside VK = %d, want 1 (untouched)", h)
+	}
+}
+
+// TestPaymentsComplianceGateOverPostgres is the named compliance regression at the integration
+// layer: a direct-origin no-ads benefit applies on the web but never inside a store wrapper.
+func TestPaymentsComplianceGateOverPostgres(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	acc := uuid.New()
+	if err := svc.Grant(ctx, acc, payments.SourceDirect, 0, 30, false); err != nil {
+		t.Fatalf("grant: %v", err)
+	}
+	present := []payments.Source{payments.SourceDirect, payments.SourceVK}
+
+	if adFree, _ := svc.AdFree(ctx, acc, payments.NewContext("direct", "web"), present); !adFree {
+		t.Error("direct no-ads should apply on web")
+	}
+	if adFree, _ := svc.AdFree(ctx, acc, payments.NewContext("vk", "android"), present); adFree {
+		t.Error("direct no-ads must NOT apply inside VK (compliance wall)")
+	}
+	if adFree, _ := svc.AdFree(ctx, acc, payments.NewContext("telegram", "web"), present); adFree {
+		t.Error("direct no-ads must NOT apply inside Telegram (compliance wall)")
+	}
+}
+
+// TestPaymentsMergeFoldsSegmentsAndBenefits verifies the merge folds chip segments (sum) and
+// benefits (hints sum, forever OR) by origin, and clears the secondary's rows, over Postgres.
+func TestPaymentsMergeFoldsSegmentsAndBenefits(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	primary, secondary := uuid.New(), uuid.New()
+	seedBalance(t, primary, "vk", 10)
+	seedBalance(t, secondary, "vk", 25)
+	seedBenefit(t, primary, "vk", 1, false)
+	seedBenefit(t, secondary, "vk", 4, true)
+
+	tx, err := testDB.BeginTx(ctx, nil)
+	if err != nil {
+		t.Fatalf("begin: %v", err)
+	}
+	if err := svc.MergeTx(ctx, tx, primary, secondary); err != nil {
+		_ = tx.Rollback()
+		t.Fatalf("merge: %v", err)
+	}
+	if err := tx.Commit(); err != nil {
+		t.Fatalf("commit: %v", err)
+	}
+	svc.Invalidate(primary, secondary)
+
+	if got := readBalance(t, primary, "vk"); got != 35 {
+		t.Errorf("merged chips = %d, want 35", got)
+	}
+	if h, forever := readBenefit(t, primary, "vk"); h != 5 || !forever {
+		t.Errorf("merged benefit = hints %d forever %v, want 5/true", h, forever)
+	}
+	if readBalance(t, secondary, "vk") != 0 {
+		t.Error("secondary balance not cleared after merge")
+	}
+}

backend/internal/inttest/promo_variant_test.go

@@ -0,0 +1,80 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"slices"
+	"strings"
+	"testing"
+
+	"github.com/google/uuid"
+	"go.uber.org/zap/zaptest"
+
+	"scrabble/backend/internal/account"
+	"scrabble/backend/internal/server"
+	"scrabble/backend/internal/session"
+)
+
+// TestTelegramAuthSeedsPromoVariantForNewUserOnly drives the sessions/telegram endpoint
+// to confirm a promo deep-link start-param seeds a brand-new account's variant
+// preferences (English Scrabble alongside the default Erudit), that a new account with no
+// such payload keeps the Erudit-only default, and that an existing account is never
+// re-seeded on a later login (the new-user-only contract).
+func TestTelegramAuthSeedsPromoVariantForNewUserOnly(t *testing.T) {
+	srv := server.New(":0", server.Deps{
+		Logger:   zaptest.NewLogger(t),
+		DB:       testDB,
+		Accounts: account.NewStore(testDB),
+		Sessions: session.NewService(session.NewStore(testDB), session.NewCache()),
+		Notifier: &captureNotifier{},
+	})
+	h := srv.Handler()
+
+	post := func(ext, startParam string) {
+		body := `{"external_id":"` + ext + `","language_code":"en","first_name":"Promo"`
+		if startParam != "" {
+			body += `,"start_param":"` + startParam + `"`
+		}
+		body += `}`
+		rec := httptest.NewRecorder()
+		req := httptest.NewRequest(http.MethodPost, "/api/v1/internal/sessions/telegram", strings.NewReader(body))
+		req.Header.Set("Content-Type", "application/json")
+		h.ServeHTTP(rec, req)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("telegram auth = %d: %s", rec.Code, rec.Body.String())
+		}
+	}
+	store := account.NewStore(testDB)
+	reload := func(ext string) []string {
+		acc, err := store.AccountByIdentity(context.Background(), account.KindTelegram, ext)
+		if err != nil {
+			t.Fatalf("lookup %s: %v", ext, err)
+		}
+		return acc.VariantPreferences
+	}
+
+	// A brand-new account reached through a promo deep-link is seeded with English
+	// Scrabble alongside the default Erudit.
+	promoExt := "tg-" + uuid.NewString()
+	post(promoExt, "verudit_ru-scrabble_en")
+	if got, want := reload(promoExt), []string{"erudit_ru", "scrabble_en"}; !slices.Equal(got, want) {
+		t.Errorf("promo new account variants = %v, want %v", got, want)
+	}
+
+	// A brand-new account with no promo payload keeps the Erudit-only default.
+	plainExt := "tg-" + uuid.NewString()
+	post(plainExt, "")
+	if got, want := reload(plainExt), []string{"erudit_ru"}; !slices.Equal(got, want) {
+		t.Errorf("plain new account variants = %v, want %v", got, want)
+	}
+
+	// A later login of the promo account, even via a different payload, must not re-seed:
+	// the seed is first-contact only.
+	post(promoExt, "vscrabble_ru")
+	if got, want := reload(promoExt), []string{"erudit_ru", "scrabble_en"}; !slices.Equal(got, want) {
+		t.Errorf("existing account re-seeded = %v, want unchanged %v", got, want)
+	}
+}

backend/internal/inttest/retention_test.go

@@ -0,0 +1,192 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"database/sql"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/account"
+	"scrabble/backend/internal/accountdelete"
+)
+
+// lastLoginIP reads an account's stamped last-login IP ("" when unset).
+func lastLoginIP(t *testing.T, accountID uuid.UUID) string {
+	t.Helper()
+	var ip sql.NullString
+	err := testDB.QueryRowContext(context.Background(),
+		"SELECT last_login_ip FROM accounts WHERE account_id = $1", accountID).Scan(&ip)
+	if err != nil {
+		t.Fatalf("read last_login_ip %s: %v", accountID, err)
+	}
+	return ip.String
+}
+
+// retainedRow is one row of the retention journal, read directly for assertions.
+type retainedRow struct {
+	kind, externalID, reason string
+}
+
+// retainedRows reads the retention journal for an account, oldest detach first.
+func retainedRows(t *testing.T, accountID uuid.UUID) []retainedRow {
+	t.Helper()
+	rows, err := testDB.QueryContext(context.Background(),
+		"SELECT kind, external_id, reason FROM retained_identities WHERE account_id = $1 ORDER BY detached_at",
+		accountID)
+	if err != nil {
+		t.Fatalf("query retained_identities %s: %v", accountID, err)
+	}
+	defer rows.Close()
+	var out []retainedRow
+	for rows.Next() {
+		var r retainedRow
+		if err := rows.Scan(&r.kind, &r.externalID, &r.reason); err != nil {
+			t.Fatalf("scan retained row: %v", err)
+		}
+		out = append(out, r)
+	}
+	return out
+}
+
+// TestUnlinkJournalsRetainedIdentity: detaching a provider records it in the retention
+// journal (reason=unlink) before the live identity is removed.
+func TestUnlinkJournalsRetainedIdentity(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+
+	tgExt := "tg-" + uuid.NewString()
+	acc, err := store.ProvisionByIdentity(ctx, account.KindTelegram, tgExt)
+	if err != nil {
+		t.Fatalf("provision: %v", err)
+	}
+	email := "keep-" + uuid.NewString() + "@example.com"
+	if err := store.AttachIdentity(ctx, acc.ID, account.KindEmail, email, true); err != nil {
+		t.Fatalf("attach email: %v", err)
+	}
+
+	if err := store.RemoveIdentity(ctx, acc.ID, account.KindTelegram); err != nil {
+		t.Fatalf("unlink telegram: %v", err)
+	}
+	got := retainedRows(t, acc.ID)
+	if len(got) != 1 || got[0].kind != account.KindTelegram || got[0].externalID != tgExt || got[0].reason != "unlink" {
+		t.Fatalf("retained rows = %+v, want one unlink telegram %q", got, tgExt)
+	}
+}
+
+// TestChangeEmailJournalsOldAddress: an email change records the outgoing address in the
+// retention journal (reason=change).
+func TestChangeEmailJournalsOldAddress(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	mailer := &capturingMailer{}
+	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
+
+	acc, err := store.ProvisionByIdentity(ctx, account.KindTelegram, "tg-"+uuid.NewString())
+	if err != nil {
+		t.Fatalf("provision: %v", err)
+	}
+	oldAddr := "old-" + uuid.NewString() + "@example.com"
+	if err := store.AttachIdentity(ctx, acc.ID, account.KindEmail, oldAddr, true); err != nil {
+		t.Fatalf("attach old email: %v", err)
+	}
+	newAddr := "new-" + uuid.NewString() + "@example.com"
+	if err := svc.RequestChangeCode(ctx, acc.ID, newAddr); err != nil {
+		t.Fatalf("request change: %v", err)
+	}
+	if _, err := svc.ConfirmChange(ctx, acc.ID, newAddr, sixDigit.FindString(mailer.lastBody)); err != nil {
+		t.Fatalf("confirm change: %v", err)
+	}
+	got := retainedRows(t, acc.ID)
+	if len(got) != 1 || got[0].kind != account.KindEmail || got[0].externalID != oldAddr || got[0].reason != "change" {
+		t.Fatalf("retained rows = %+v, want one change email %q", got, oldAddr)
+	}
+}
+
+// TestStampLastLoginThrottles: the first cold-load stamp writes the IP; a second within
+// the hour is a no-op (throttled), so it costs at most one write per account per hour.
+func TestStampLastLoginThrottles(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	acc, err := store.ProvisionByIdentity(ctx, account.KindTelegram, "tg-"+uuid.NewString())
+	if err != nil {
+		t.Fatalf("provision: %v", err)
+	}
+	if err := store.StampLastLogin(ctx, acc.ID, "1.2.3.4"); err != nil {
+		t.Fatalf("first stamp: %v", err)
+	}
+	if got := lastLoginIP(t, acc.ID); got != "1.2.3.4" {
+		t.Fatalf("first stamp ip = %q, want 1.2.3.4", got)
+	}
+	if err := store.StampLastLogin(ctx, acc.ID, "9.9.9.9"); err != nil {
+		t.Fatalf("second stamp: %v", err)
+	}
+	if got := lastLoginIP(t, acc.ID); got != "1.2.3.4" {
+		t.Fatalf("throttled ip = %q, want unchanged 1.2.3.4", got)
+	}
+}
+
+// TestReapExpiredRetention: the reaper keeps journal rows newer than the cutoff and purges
+// older ones, and drops a long-deleted account's feedback thread + dossier PII.
+func TestReapExpiredRetention(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	deleter := accountdelete.NewDeleter(testDB)
+
+	// An unlinked provider leaves a journal row detached "now".
+	tgExt := "tg-" + uuid.NewString()
+	acc, err := store.ProvisionByIdentity(ctx, account.KindTelegram, tgExt)
+	if err != nil {
+		t.Fatalf("provision: %v", err)
+	}
+	if err := store.AttachIdentity(ctx, acc.ID, account.KindEmail, "keep-"+uuid.NewString()+"@example.com", true); err != nil {
+		t.Fatalf("attach email: %v", err)
+	}
+	if err := store.RemoveIdentity(ctx, acc.ID, account.KindTelegram); err != nil {
+		t.Fatalf("unlink: %v", err)
+	}
+	// A cutoff before the detach keeps the row.
+	if _, _, err := store.ReapExpiredRetention(ctx, time.Now().Add(-time.Hour)); err != nil {
+		t.Fatalf("reap (early cutoff): %v", err)
+	}
+	if got := retainedRows(t, acc.ID); len(got) != 1 {
+		t.Fatalf("journal after early-cutoff reap = %+v, want kept", got)
+	}
+	// A cutoff after the detach purges it.
+	if _, _, err := store.ReapExpiredRetention(ctx, time.Now().Add(time.Hour)); err != nil {
+		t.Fatalf("reap (late cutoff): %v", err)
+	}
+	if got := retainedRows(t, acc.ID); len(got) != 0 {
+		t.Fatalf("journal after late-cutoff reap = %+v, want purged", got)
+	}
+
+	// A deleted account past the cutoff loses its feedback thread and dossier PII.
+	del, _, err := store.ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "ru", "", "Иван", "")
+	if err != nil {
+		t.Fatalf("provision deletee: %v", err)
+	}
+	if _, err := testDB.ExecContext(ctx,
+		"INSERT INTO feedback_messages (message_id, account_id, body, channel) VALUES ($1, $2, 'hi', 'web')",
+		uuid.New(), del.ID); err != nil {
+		t.Fatalf("insert feedback: %v", err)
+	}
+	if err := deleter.AnonymizeAndTombstone(ctx, del.ID); err != nil {
+		t.Fatalf("delete: %v", err)
+	}
+	if _, fb, err := store.ReapExpiredRetention(ctx, time.Now().Add(time.Hour)); err != nil || fb == 0 {
+		t.Fatalf("reap deleted = (fb %d, err %v), want fb>=1", fb, err)
+	}
+	if name, _ := deletedFields(t, del.ID); name != "" {
+		t.Errorf("deleted_display_name after reap = %q, want cleared", name)
+	}
+	var fbCount int
+	if err := testDB.QueryRowContext(ctx, "SELECT count(*) FROM feedback_messages WHERE account_id = $1", del.ID).Scan(&fbCount); err != nil {
+		t.Fatalf("count feedback: %v", err)
+	}
+	if fbCount != 0 {
+		t.Errorf("feedback rows after reap = %d, want 0", fbCount)
+	}
+}

backend/internal/inttest/session_platform_test.go

@@ -0,0 +1,178 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"database/sql"
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/pressly/goose/v3"
+	testcontainers "github.com/testcontainers/testcontainers-go"
+	tcpostgres "github.com/testcontainers/testcontainers-go/modules/postgres"
+	"github.com/testcontainers/testcontainers-go/wait"
+
+	"scrabble/backend/internal/account"
+	"scrabble/backend/internal/postgres"
+	"scrabble/backend/internal/postgres/migrations"
+	"scrabble/backend/internal/session"
+)
+
+// TestSessionPlatformCaptureAndUntrusted proves a session round-trips its captured
+// platform through create and a cold-cache (DB-backed) resolve for each kind, and
+// that an unattributed session records no platform — the untrusted, view-only case.
+func TestSessionPlatformCaptureAndUntrusted(t *testing.T) {
+	ctx := context.Background()
+	accounts := account.NewStore(testDB)
+	store := session.NewStore(testDB)
+	svc := session.NewService(store, session.NewCache())
+
+	for _, tc := range []struct {
+		name     string
+		platform session.Platform
+	}{
+		{"vk-ios", session.Platform{Kind: session.PlatformKindVK, Subtype: session.SubtypeIOS}},
+		{"telegram-android", session.Platform{Kind: session.PlatformKindTelegram, Subtype: session.SubtypeAndroid}},
+		{"direct-web", session.Platform{Kind: session.PlatformKindDirect, Subtype: session.SubtypeWeb}},
+		{"untrusted", session.Platform{}},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			acc, err := accounts.ProvisionByIdentity(ctx, account.KindTelegram, "tg-"+uuid.NewString())
+			if err != nil {
+				t.Fatalf("provision: %v", err)
+			}
+			token, sess, err := svc.Create(ctx, acc.ID, tc.platform)
+			if err != nil {
+				t.Fatalf("create: %v", err)
+			}
+			if sess.Platform != tc.platform {
+				t.Errorf("created platform = %+v, want %+v", sess.Platform, tc.platform)
+			}
+			// Resolve through a cold cache so the value comes back via the DB columns.
+			cold := session.NewService(store, session.NewCache())
+			if err := cold.Warm(ctx); err != nil {
+				t.Fatalf("warm: %v", err)
+			}
+			got, err := cold.Resolve(ctx, token)
+			if err != nil {
+				t.Fatalf("resolve: %v", err)
+			}
+			if got.Platform != tc.platform {
+				t.Errorf("resolved platform = %+v, want %+v", got.Platform, tc.platform)
+			}
+			if got.Platform.Trusted() != tc.platform.Trusted() {
+				t.Errorf("resolved Trusted() = %v, want %v", got.Platform.Trusted(), tc.platform.Trusted())
+			}
+		})
+	}
+}
+
+// TestSessionPlatformCheckConstraints proves the CHECK constraints reject an
+// out-of-range kind or subtype, so a corrupt value cannot be persisted.
+func TestSessionPlatformCheckConstraints(t *testing.T) {
+	ctx := context.Background()
+	acc, err := account.NewStore(testDB).ProvisionByIdentity(ctx, account.KindTelegram, "tg-"+uuid.NewString())
+	if err != nil {
+		t.Fatalf("provision: %v", err)
+	}
+	const pgCheckViolation = "23514"
+	for _, tc := range []struct {
+		name    string
+		kind    string
+		subtype string
+	}{
+		{"bad-kind", "facebook", "web"},
+		{"bad-subtype", "vk", "windows"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			_, err := testDB.ExecContext(ctx,
+				`INSERT INTO backend.sessions (session_id, account_id, token_hash, platform_kind, platform_subtype)
+				 VALUES ($1, $2, $3, $4, $5)`,
+				uuid.New(), acc.ID, uuid.NewString(), tc.kind, tc.subtype)
+			if !isPgCode(err, pgCheckViolation) {
+				t.Errorf("insert %s: err = %v, want check_violation", tc.name, err)
+			}
+		})
+	}
+}
+
+// TestSessionPlatformMigrationReversible proves migration 00011 is expand-contract:
+// it applies, rolls back (dropping the platform columns), and re-applies cleanly —
+// so a backend image rollback stays DB-safe. It uses its own container so the Down
+// does not disturb the shared suite database.
+func TestSessionPlatformMigrationReversible(t *testing.T) {
+	ctx := context.Background()
+
+	container, err := tcpostgres.Run(ctx, pgImage,
+		tcpostgres.WithDatabase(pgDatabase),
+		tcpostgres.WithUsername(pgUser),
+		tcpostgres.WithPassword(pgPassword),
+		testcontainers.WithWaitStrategy(
+			wait.ForLog("database system is ready to accept connections").
+				WithOccurrence(2).
+				WithStartupTimeout(containerStartup),
+		),
+	)
+	if err != nil {
+		t.Fatalf("start container: %v", err)
+	}
+	defer func() { _ = container.Terminate(context.Background()) }()
+
+	baseDSN, err := container.ConnectionString(ctx, "sslmode=disable")
+	if err != nil {
+		t.Fatalf("connection string: %v", err)
+	}
+	dsn, err := withSearchPath(baseDSN, pgSchema)
+	if err != nil {
+		t.Fatalf("search path: %v", err)
+	}
+	cfg := postgres.DefaultConfig()
+	cfg.DSN = dsn
+	db, err := postgres.Open(ctx, cfg)
+	if err != nil {
+		t.Fatalf("open pool: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	if err := postgres.ApplyMigrations(ctx, db); err != nil {
+		t.Fatalf("apply up: %v", err)
+	}
+	if !sessionsPlatformColumnsExist(ctx, t, db) {
+		t.Fatal("platform columns absent after up")
+	}
+
+	goose.SetBaseFS(migrations.Migrations())
+	defer goose.SetBaseFS(nil)
+	if err := goose.SetDialect("postgres"); err != nil {
+		t.Fatalf("set dialect: %v", err)
+	}
+	// Down past 00011 (to 00010) and assert the columns are gone.
+	if err := goose.DownToContext(ctx, db, ".", 10); err != nil {
+		t.Fatalf("down to 10: %v", err)
+	}
+	if sessionsPlatformColumnsExist(ctx, t, db) {
+		t.Error("platform columns survived the down migration")
+	}
+	// Re-apply and assert they return.
+	if err := goose.UpContext(ctx, db, "."); err != nil {
+		t.Fatalf("re-apply up: %v", err)
+	}
+	if !sessionsPlatformColumnsExist(ctx, t, db) {
+		t.Fatal("platform columns absent after re-apply")
+	}
+}
+
+// sessionsPlatformColumnsExist reports whether both platform columns are present on
+// backend.sessions.
+func sessionsPlatformColumnsExist(ctx context.Context, t *testing.T, db *sql.DB) bool {
+	t.Helper()
+	var n int
+	if err := db.QueryRowContext(ctx,
+		`SELECT count(*) FROM information_schema.columns
+		 WHERE table_schema = 'backend' AND table_name = 'sessions'
+		   AND column_name IN ('platform_kind', 'platform_subtype')`).Scan(&n); err != nil {
+		t.Fatalf("count platform columns: %v", err)
+	}
+	return n == 2
+}

backend/internal/inttest/session_test.go

@@ -26,7 +26,8 @@ func TestSessionLifecycle(t *testing.T) {
 	store := session.NewStore(testDB)
 	svc := session.NewService(store, session.NewCache())
 
-	token, sess, err := svc.Create(ctx, acc.ID)
+	platform := session.Platform{Kind: session.PlatformKindVK, Subtype: session.SubtypeIOS}
+	token, sess, err := svc.Create(ctx, acc.ID, platform)
 	if err != nil {
 		t.Fatalf("create session: %v", err)
 	}
@@ -36,6 +37,9 @@ func TestSessionLifecycle(t *testing.T) {
 	if token == sess.TokenHash {
 		t.Error("plaintext token must not equal the stored hash")
 	}
+	if sess.Platform != platform {
+		t.Errorf("session platform = %+v, want %+v", sess.Platform, platform)
+	}
 
 	// Resolve via the warm write-through cache.
 	got, err := svc.Resolve(ctx, token)
@@ -63,8 +67,8 @@ func TestSessionLifecycle(t *testing.T) {
 	if _, ok := cold.Get(session.HashToken(token)); !ok {
 		t.Error("Warm must load the active session into the cache")
 	}
-	if got2, err := svc2.Resolve(ctx, token); err != nil || got2.ID != sess.ID {
-		t.Errorf("resolve after warm = (%s, %v), want %s", got2.ID, err, sess.ID)
+	if got2, err := svc2.Resolve(ctx, token); err != nil || got2.ID != sess.ID || got2.Platform != platform {
+		t.Errorf("resolve after warm = (%s, %+v, %v), want %s / %+v", got2.ID, got2.Platform, err, sess.ID, platform)
 	}
 
 	// Revoke, then the token no longer resolves; revoke again is a no-op.

backend/internal/link/service.go

@@ -133,6 +133,53 @@ func (s *Service) attachTelegram(ctx context.Context, callerID uuid.UUID, extern
 	return s.accounts.ClearGuest(ctx, callerID)
 }
 
+// ConfirmVK attaches a gateway-validated VK identity to the caller (Linked) or
+// reports that it belongs to another account (MergeRequired). The gateway has already
+// completed the VK ID code exchange, so externalID is the trusted vk user id.
+func (s *Service) ConfirmVK(ctx context.Context, callerID uuid.UUID, externalID string) (ConfirmResult, error) {
+	owner, ok, err := s.accounts.AccountIDByIdentity(ctx, account.KindVK, externalID)
+	if err != nil {
+		return ConfirmResult{}, err
+	}
+	if !ok {
+		if err := s.attachVK(ctx, callerID, externalID); err != nil {
+			return ConfirmResult{}, err
+		}
+		return ConfirmResult{Linked: true}, nil
+	}
+	if owner == callerID {
+		return ConfirmResult{Linked: true}, nil
+	}
+	return ConfirmResult{MergeRequired: true, SecondaryID: owner}, nil
+}
+
+// MergeVK merges the account owning a gateway-validated VK identity into the caller's
+// (subject to the guest-primary rule).
+func (s *Service) MergeVK(ctx context.Context, callerID uuid.UUID, externalID string) (MergeResult, error) {
+	owner, ok, err := s.accounts.AccountIDByIdentity(ctx, account.KindVK, externalID)
+	if err != nil {
+		return MergeResult{}, err
+	}
+	if !ok {
+		if err := s.attachVK(ctx, callerID, externalID); err != nil {
+			return MergeResult{}, err
+		}
+		return MergeResult{PrimaryID: callerID}, nil
+	}
+	if owner == callerID {
+		return MergeResult{PrimaryID: callerID}, nil
+	}
+	return s.merge(ctx, callerID, owner)
+}
+
+// attachVK links the identity to the caller and promotes a guest.
+func (s *Service) attachVK(ctx context.Context, callerID uuid.UUID, externalID string) error {
+	if err := s.accounts.AttachIdentity(ctx, callerID, account.KindVK, externalID, true); err != nil {
+		return err
+	}
+	return s.accounts.ClearGuest(ctx, callerID)
+}
+
 // merge decides the primary (the caller, unless it is a guest and the other is
 // durable), runs the data merge, retires the secondary's sessions and mints a new
 // session when the active account switches.
@@ -153,7 +200,11 @@ func (s *Service) merge(ctx context.Context, callerID, otherID uuid.UUID) (Merge
 	}
 	res := MergeResult{PrimaryID: primary}
 	if primary != callerID {
-		token, _, err := s.sessions.Create(ctx, primary)
+		// The switched-to session inherits the caller's current trusted platform
+		// (the context the merge was initiated from); absent when the caller's
+		// session itself is untrusted.
+		platform, _ := session.PlatformFromContext(ctx)
+		token, _, err := s.sessions.Create(ctx, primary, platform)
 		if err != nil {
 			return MergeResult{}, err
 		}

backend/internal/notify/events.go

@@ -155,6 +155,13 @@ func Notification(userID uuid.UUID, kind string) Intent {
 	return Intent{UserID: userID, Kind: KindNotification, Payload: b.FinishedBytes(), EventID: eventID()}
 }
 
+// ProfileChanged is a payload-free "re-fetch your profile" signal to userID, emitted
+// when the viewer's own account changed out of band — an email confirmed through the
+// one-tap deeplink opened in another browser.
+func ProfileChanged(userID uuid.UUID) Intent {
+	return Notification(userID, NotifyProfile)
+}
+
 // NotificationAccount builds a lobby notification of one of the friend_* kinds carrying the
 // account it concerns (the requester, the new friend or the decliner), so the client updates its
 // requests/friends lists and the in-game "add friend" state without a refetch.

backend/internal/notify/notify.go

@@ -69,6 +69,10 @@ const (
 	// it re-fetches profile.get to show or hide the banner. It carries no payload (the
 	// banner set rides the profile response). In-app only.
 	NotifyBanner = "banner"
+	// NotifyProfile tells the client that the viewer's own profile changed out of band
+	// (e.g. an email was confirmed via the one-tap deeplink opened in another browser),
+	// so it re-fetches profile.get. It carries no payload. In-app only.
+	NotifyProfile = "profile"
 	// NotifyUserBlocked confirms to the blocker that a per-user block took effect,
 	// carrying the blocked account, so every one of the blocker's sessions updates the
 	// in-game block/add-friend controls and the struck name in place. It is delivered

backend/internal/payments/boundary_test.go

@@ -0,0 +1,57 @@
+package payments
+
+import (
+	"go/parser"
+	"go/token"
+	"io/fs"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+// TestPaymentsSchemaImportBoundary enforces that only this package reaches the
+// payments jet code. The payments schema is isolated behind this domain; the
+// application connects to Postgres as a superuser that bypasses the schema
+// grants, so the runtime wall that keeps every other package out of payments.*
+// is this import boundary, not the DB privileges. If another package imported
+// the generated payments tables it could issue SQL against the schema directly,
+// breaking the single-writer guarantee and the domain's extractability.
+func TestPaymentsSchemaImportBoundary(t *testing.T) {
+	const jetPkg = "scrabble/backend/internal/postgres/jet/payments"
+
+	_, thisFile, _, ok := runtime.Caller(0)
+	if !ok {
+		t.Fatal("cannot resolve the test file path")
+	}
+	// thisFile = .../backend/internal/payments/boundary_test.go
+	backendRoot := filepath.Clean(filepath.Join(filepath.Dir(thisFile), "..", ".."))
+	allowedPrefix := filepath.Join(backendRoot, "internal", "payments") + string(filepath.Separator)
+
+	fset := token.NewFileSet()
+	walkErr := filepath.WalkDir(backendRoot, func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if d.IsDir() || !strings.HasSuffix(path, ".go") {
+			return nil
+		}
+		file, perr := parser.ParseFile(fset, path, nil, parser.ImportsOnly)
+		if perr != nil {
+			return perr
+		}
+		for _, imp := range file.Imports {
+			p := strings.Trim(imp.Path.Value, `"`)
+			if p != jetPkg && !strings.HasPrefix(p, jetPkg+"/") {
+				continue
+			}
+			if !strings.HasPrefix(path, allowedPrefix) {
+				t.Errorf("%s imports %s — only internal/payments may reach the payments jet code", path, p)
+			}
+		}
+		return nil
+	})
+	if walkErr != nil {
+		t.Fatalf("walk backend tree: %v", walkErr)
+	}
+}

backend/internal/payments/cache.go

@@ -0,0 +1,72 @@
+package payments
+
+import (
+	"sync"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+// benefitState is an account's benefit row for one origin: the no-ads term end (nil = none),
+// the perpetual forever flag, and the hint count. It is the context-independent stored form;
+// the read paths aggregate it over the origins applicable in a context.
+type benefitState struct {
+	adsPaidUntil *time.Time
+	adsForever   bool
+	hints        int
+}
+
+// walletState is an account's full payments state: chip balances by source and benefits by
+// origin. It is the raw, context-independent data every read path filters per execution
+// context — the value the cache holds and the store recomputes from the materialized tables.
+type walletState struct {
+	chips    map[Source]int
+	benefits map[Source]benefitState
+}
+
+// chipsOf returns the chip balance for a source, zero when the segment has no row (an absent
+// segment reads as zero, §2).
+func (w walletState) chipsOf(s Source) int { return w.chips[s] }
+
+// benefitOf returns the benefit for an origin, the zero benefit when the origin has no row.
+func (w walletState) benefitOf(o Source) benefitState { return w.benefits[o] }
+
+// walletCache is the payments read model: each account's chip/benefit state, keyed by account
+// id, read on every ad-eligibility / hint / wallet / gate request and invalidated on every
+// payments mutation (spend, grant, fund, refund, merge). It is a write-through cache in front
+// of the materialized balances/benefits tables — the same pattern the account-suspension gate
+// uses (backend/internal/account/suspension.go) — so the steady-state hot path issues no query
+// to the payments schema. It is single-instance, matching the deployment (one shared Store); a
+// multi-instance backend would need a shared cache.
+type walletCache struct {
+	mu sync.RWMutex
+	m  map[uuid.UUID]walletState
+}
+
+// newWalletCache constructs an empty cache.
+func newWalletCache() *walletCache {
+	return &walletCache{m: make(map[uuid.UUID]walletState)}
+}
+
+// get returns the cached state for an account and whether it was present.
+func (c *walletCache) get(id uuid.UUID) (walletState, bool) {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	s, ok := c.m[id]
+	return s, ok
+}
+
+// put stores an account's state.
+func (c *walletCache) put(id uuid.UUID, s walletState) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.m[id] = s
+}
+
+// invalidate drops an account's entry so the next read reloads it from the materialized tables.
+// Called after every mutation once its transaction has committed.
+func (c *walletCache) invalidate(id uuid.UUID) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	delete(c.m, id)
+}

backend/internal/payments/catalog.go

@@ -0,0 +1,82 @@
+package payments
+
+// AtomQty is one atom line of a catalog product in the read model: the base value type it grants
+// (chips / hints / no-ads days / tournament) and how many of it the product carries.
+type AtomQty struct {
+	AtomType string
+	Quantity int
+}
+
+// CatalogProduct is one storefront product projected for the execution context. A value is
+// bought with chips, so it carries Chips (its uniform chip price) and no money price. A chip pack
+// funds chips with money, so it carries MoneyAmount (minor units) and MoneyCurrency for the
+// context's payment method and no chip price. Atoms lists what the product grants.
+type CatalogProduct struct {
+	Kind          string // "value" (bought with chips) or "pack" (funds chips with money)
+	ProductID     string
+	Title         string
+	Chips         int    // a value's uniform chip price; 0 for a pack
+	MoneyAmount   int64  // a pack's price in the context currency's minor units; 0 for a value
+	MoneyCurrency string // a pack's currency for the context method; empty for a value
+	Atoms         []AtomQty
+}
+
+// CatalogView is the storefront read model for one execution context: the products a player sees
+// and can buy there — every chip-priced value plus the chip packs priced in the context's method.
+type CatalogView struct {
+	Products []CatalogProduct
+}
+
+// atomChips is the atom type that marks a product as a chip pack (it funds chips) rather than a
+// value (bought with chips). A value never carries it.
+const atomChips = "chips"
+
+// projectCatalog turns the raw active catalog into the storefront for the context. A value (no
+// chips atom) is shown everywhere at its CHIP price. A chip pack is shown only when it carries a
+// price for the context's payment method (cxt.Kind: vk / telegram / direct), priced in that
+// method's currency. A value missing its CHIP price and a pack missing a price for the context
+// method are omitted (misconfigured or unavailable there). An untrusted context (empty Kind) has
+// no method, so only values show; buying is gated server-side regardless.
+func projectCatalog(entries []catalogEntry, cxt Context) CatalogView {
+	var out CatalogView
+	for _, e := range entries {
+		isPack := false
+		atoms := make([]AtomQty, 0, len(e.atoms))
+		for _, a := range e.atoms {
+			atoms = append(atoms, AtomQty{AtomType: a.atomType, Quantity: a.quantity})
+			if a.atomType == atomChips {
+				isPack = true
+			}
+		}
+		p := CatalogProduct{ProductID: e.id.String(), Title: e.title, Atoms: atoms}
+		if isPack {
+			pr, ok := findPrice(e.prices, string(cxt.Kind))
+			if !ok {
+				continue // no price for this context's method — not purchasable here
+			}
+			p.Kind = "pack"
+			p.MoneyAmount = pr.amount
+			p.MoneyCurrency = string(pr.currency)
+		} else {
+			pr, ok := findPrice(e.prices, "")
+			if !ok {
+				continue // a value must carry a CHIP price
+			}
+			p.Kind = "value"
+			p.Chips = int(pr.amount)
+		}
+		out.Products = append(out.Products, p)
+	}
+	return out
+}
+
+// findPrice returns the price row for the given payment method — the empty string selects a
+// value's CHIP price row (stored with a NULL method).
+func findPrice(prices []priceRow, method string) (priceRow, bool) {
+	for _, pr := range prices {
+		if pr.method == method {
+			return pr, true
+		}
+	}
+	return priceRow{}, false
+}

backend/internal/payments/catalog_test.go

@@ -0,0 +1,136 @@
+package payments
+
+import (
+	"testing"
+
+	"github.com/google/uuid"
+)
+
+// catalog fixtures: a chip-priced value (hints), a multi-method chip pack, a VK-only chip pack, a
+// value with no CHIP price (misconfigured), and a pack whose only method is telegram.
+func fixtureCatalog() []catalogEntry {
+	value := catalogEntry{
+		id:    uuid.MustParse("00000000-0000-0000-0000-000000000001"),
+		title: "250 hints",
+		atoms: []atomQty{{atomType: "hints", quantity: 250}},
+		prices: []priceRow{
+			{method: "", currency: CurrencyChip, amount: 500},
+		},
+	}
+	pack := catalogEntry{
+		id:    uuid.MustParse("00000000-0000-0000-0000-000000000002"),
+		title: "100 chips",
+		atoms: []atomQty{{atomType: "chips", quantity: 100}},
+		prices: []priceRow{
+			{method: "vk", currency: CurrencyVote, amount: 20},
+			{method: "telegram", currency: CurrencyStar, amount: 25},
+			{method: "direct", currency: CurrencyRUB, amount: 14900},
+		},
+	}
+	vkOnlyPack := catalogEntry{
+		id:    uuid.MustParse("00000000-0000-0000-0000-000000000003"),
+		title: "VK-only chips",
+		atoms: []atomQty{{atomType: "chips", quantity: 50}},
+		prices: []priceRow{
+			{method: "vk", currency: CurrencyVote, amount: 10},
+		},
+	}
+	brokenValue := catalogEntry{
+		id:    uuid.MustParse("00000000-0000-0000-0000-000000000004"),
+		title: "no chip price",
+		atoms: []atomQty{{atomType: "noads_days", quantity: 30}},
+		// no CHIP price row — misconfigured, must be omitted
+	}
+	return []catalogEntry{value, pack, vkOnlyPack, brokenValue}
+}
+
+// byID indexes a projected storefront by product id for assertions.
+func byID(v CatalogView) map[string]CatalogProduct {
+	m := make(map[string]CatalogProduct, len(v.Products))
+	for _, p := range v.Products {
+		m[p.ProductID] = p
+	}
+	return m
+}
+
+func TestProjectCatalog_ContextMatrix(t *testing.T) {
+	const (
+		valueID  = "00000000-0000-0000-0000-000000000001"
+		packID   = "00000000-0000-0000-0000-000000000002"
+		vkPackID = "00000000-0000-0000-0000-000000000003"
+		brokenID = "00000000-0000-0000-0000-000000000004"
+	)
+	entries := fixtureCatalog()
+
+	tests := []struct {
+		name        string
+		cxt         Context
+		wantPackAmt int64
+		wantPackCur Currency
+		wantVKPack  bool // the vk-only pack visible?
+	}{
+		{"vk", Context{Kind: SourceVK}, 20, CurrencyVote, true},
+		{"vk-ios frozen still lists vk price", Context{Kind: SourceVK, Subtype: SubtypeIOS}, 20, CurrencyVote, true},
+		{"telegram", Context{Kind: SourceTelegram}, 25, CurrencyStar, false},
+		{"direct", Context{Kind: SourceDirect}, 14900, CurrencyRUB, false},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := byID(projectCatalog(entries, tc.cxt))
+
+			// The value shows everywhere at its uniform chip price, never a money price.
+			v, ok := got[valueID]
+			if !ok {
+				t.Fatalf("value missing from %s storefront", tc.name)
+			}
+			if v.Kind != "value" || v.Chips != 500 || v.MoneyCurrency != "" || v.MoneyAmount != 0 {
+				t.Errorf("value = %+v, want kind=value chips=500 no money", v)
+			}
+			if len(v.Atoms) != 1 || v.Atoms[0].AtomType != "hints" || v.Atoms[0].Quantity != 250 {
+				t.Errorf("value atoms = %+v, want [hints:250]", v.Atoms)
+			}
+
+			// The multi-method pack shows the context method's price, in that currency, no chips.
+			p, ok := got[packID]
+			if !ok {
+				t.Fatalf("pack missing from %s storefront", tc.name)
+			}
+			if p.Kind != "pack" || p.Chips != 0 || p.MoneyAmount != tc.wantPackAmt || p.MoneyCurrency != string(tc.wantPackCur) {
+				t.Errorf("pack = %+v, want kind=pack amount=%d currency=%s", p, tc.wantPackAmt, tc.wantPackCur)
+			}
+
+			// The vk-only pack shows only where a vk price exists.
+			if _, ok := got[vkPackID]; ok != tc.wantVKPack {
+				t.Errorf("vk-only pack present=%v, want %v (%s)", ok, tc.wantVKPack, tc.name)
+			}
+
+			// The misconfigured value (no CHIP price) is never shown.
+			if _, ok := got[brokenID]; ok {
+				t.Errorf("misconfigured value must be omitted (%s)", tc.name)
+			}
+		})
+	}
+}
+
+// An untrusted context (empty Kind) has no payment method, so it shows values only — no packs.
+func TestProjectCatalog_UntrustedShowsValuesOnly(t *testing.T) {
+	got := byID(projectCatalog(fixtureCatalog(), Context{}))
+	if _, ok := got["00000000-0000-0000-0000-000000000001"]; !ok {
+		t.Error("untrusted context should still list the chip-priced value")
+	}
+	for _, id := range []string{
+		"00000000-0000-0000-0000-000000000002",
+		"00000000-0000-0000-0000-000000000003",
+	} {
+		if _, ok := got[id]; ok {
+			t.Errorf("untrusted context must not list pack %s", id)
+		}
+	}
+}
+
+// An empty catalog projects to an empty storefront (no products seeded yet — the Release-1 state).
+func TestProjectCatalog_Empty(t *testing.T) {
+	if got := projectCatalog(nil, Context{Kind: SourceDirect}); len(got.Products) != 0 {
+		t.Errorf("empty catalog projected %d products, want 0", len(got.Products))
+	}
+}

backend/internal/payments/gate.go

@@ -0,0 +1,202 @@
+package payments
+
+import (
+	"slices"
+	"time"
+)
+
+// Source is the platform axis a chip balance is segmented by (where it was funded) and a
+// benefit is stamped with (where it was bought — its origin). The two roles share this value
+// set but mean different things (see docs/PAYMENTS.md §3); Source names the axis for both.
+type Source string
+
+const (
+	// SourceVK is the VK platform: Votes purchases and VK rewarded ads fund here.
+	SourceVK Source = "vk"
+	// SourceTelegram is the Telegram platform: Stars purchases fund here.
+	SourceTelegram Source = "telegram"
+	// SourceDirect is the open web / native context: Robokassa purchases fund here.
+	SourceDirect Source = "direct"
+)
+
+// Valid reports whether s is one of the three known platform sources.
+func (s Source) Valid() bool {
+	switch s {
+	case SourceVK, SourceTelegram, SourceDirect:
+		return true
+	default:
+		return false
+	}
+}
+
+// SubtypeIOS is the one device subtype the gate keys on: VK on iOS is frozen for spending
+// (Apple forbids spending virtual currency on digital goods outside IAP). It is trusted only
+// for VK, where it rides inside the signed launch parameters.
+const SubtypeIOS = "ios"
+
+// SourceForIdentityKind maps a backend identity kind to the payments source whose segment that
+// identity makes available: a vk/telegram identity to its own source, a durable email identity
+// to the direct source (the web/native recovery anchor). A robot identity — or any unknown
+// kind — maps to no source (second return false). Callers use it to build the present set the
+// payments interface takes, since payments cannot read the account schema.
+func SourceForIdentityKind(kind string) (Source, bool) {
+	switch kind {
+	case "vk":
+		return SourceVK, true
+	case "telegram":
+		return SourceTelegram, true
+	case "email":
+		return SourceDirect, true
+	default:
+		return "", false
+	}
+}
+
+// PresentSources maps an account's identity kinds to the payments sources they make available
+// (§6), de-duplicated: vk→vk, telegram→telegram, email→direct; a robot or unknown kind maps to
+// nothing. Callers pass the kinds from account.Identities so the gate — which holds no
+// cross-schema identity knowledge — can resolve which segments are awake.
+func PresentSources(kinds []string) []Source {
+	var out []Source
+	for _, k := range kinds {
+		if s, ok := SourceForIdentityKind(k); ok && !has(out, s) {
+			out = append(out, s)
+		}
+	}
+	return out
+}
+
+// Context is the trusted execution context the store-compliance gate keys on: the platform
+// Kind (the source the wrapper enforces) plus, for VK, the trusted Subtype (only the VK-iOS
+// freeze depends on it). The zero Context (empty Kind) is an untrusted platform — the gate is
+// fail-closed there: no spend, no purchase, no foreign-origin benefit, view only.
+type Context struct {
+	Kind    Source
+	Subtype string
+}
+
+// NewContext builds a Context from the session platform's kind and subtype strings (as carried
+// on the trusted X-Platform signal). An unrecognised or empty kind yields an untrusted Context.
+func NewContext(kind, subtype string) Context {
+	k := Source(kind)
+	if !k.Valid() {
+		return Context{}
+	}
+	return Context{Kind: k, Subtype: subtype}
+}
+
+// Trusted reports whether the platform is trusted (a known kind). An untrusted context denies
+// every spend/purchase and the application of any foreign origin.
+func (c Context) Trusted() bool { return c.Kind.Valid() }
+
+// vkFrozen reports whether this is the VK-iOS spend freeze: VK context on the trusted iOS
+// subtype. A previously bought benefit still applies there, but no spend or purchase is possible.
+func (c Context) vkFrozen() bool { return c.Kind == SourceVK && c.Subtype == SubtypeIOS }
+
+// spendPriority is the fixed draw order when several segments are spendable in one context
+// (D7): the "home" direct segment first, the store-funded segments after.
+var spendPriority = []Source{SourceDirect, SourceVK, SourceTelegram}
+
+// has reports whether present contains s.
+func has(present []Source, s Source) bool {
+	return slices.Contains(present, s)
+}
+
+// spendableSources returns the chip segments that may be SPENT in the context, in draw-priority
+// order, restricted to the sources the account actually has (present). It is empty when the
+// platform is untrusted (fail-closed) or VK-iOS (frozen): inside VK/TG only the same-named
+// segment is spendable; on web/native all attached segments are, drained direct→vk→tg.
+func spendableSources(c Context, present []Source) []Source {
+	if !c.Trusted() || c.vkFrozen() {
+		return nil
+	}
+	switch c.Kind {
+	case SourceVK, SourceTelegram:
+		if has(present, c.Kind) {
+			return []Source{c.Kind}
+		}
+		return nil
+	default: // direct (web/native)
+		var out []Source
+		for _, s := range spendPriority {
+			if has(present, s) {
+				out = append(out, s)
+			}
+		}
+		return out
+	}
+}
+
+// applicableOrigins returns the benefit origins that APPLY in the context, in draw-priority
+// order, restricted to present sources. It differs from spendableSources in one way: VK-iOS is
+// NOT excluded — a benefit bought earlier still applies while spending is frozen. Inside VK/TG
+// only the same-named origin applies (a foreign, e.g. direct, origin never activates inside a
+// store — the compliance wall); on web/native direct+vk+tg all apply, drained direct→vk→tg.
+func applicableOrigins(c Context, present []Source) []Source {
+	if !c.Trusted() {
+		return nil
+	}
+	switch c.Kind {
+	case SourceVK, SourceTelegram:
+		if has(present, c.Kind) {
+			return []Source{c.Kind}
+		}
+		return nil
+	default: // direct (web/native)
+		var out []Source
+		for _, s := range spendPriority {
+			if has(present, s) {
+				out = append(out, s)
+			}
+		}
+		return out
+	}
+}
+
+// visibleSources returns the segments the wallet shows in the context, regardless of whether
+// they are spendable: inside a store only the same-named segment (the others are invisible
+// there); on web/native or an untrusted context all three (untrusted shows them view-only).
+func visibleSources(c Context) []Source {
+	switch c.Kind {
+	case SourceVK, SourceTelegram:
+		return []Source{c.Kind}
+	default:
+		return spendPriority
+	}
+}
+
+// Segment is one chip balance the wallet shows: the source, its chip count, and whether it can
+// be spent in the current context (false for a frozen VK-iOS balance or an untrusted platform).
+type Segment struct {
+	Source    Source
+	Chips     int
+	Spendable bool
+}
+
+// BenefitView is the benefit state applicable in the current context: whether ads are off (and
+// until when, or forever) and how many hints are available. It aggregates over the origins
+// applicable in the context (§5).
+type BenefitView struct {
+	AdsForever   bool
+	AdsPaidUntil *time.Time
+	Hints        int
+}
+
+// WalletView is the read model returned to the wallet: the visible segments plus the
+// context-applicable benefits.
+type WalletView struct {
+	Segments []Segment
+	Benefits BenefitView
+}
+
+// benefitDelta is the benefit change a spend or grant applies to one origin: hints added, a
+// no-ads term in whole days (stacked from max(now, current end)), and the perpetual forever
+// flag (which overrides terms).
+type benefitDelta struct {
+	hintsAdd  int
+	noAdsDays int
+	forever   bool
+}
+
+// zero reports whether the delta changes nothing.
+func (d benefitDelta) zero() bool { return d.hintsAdd == 0 && d.noAdsDays == 0 && !d.forever }

backend/internal/payments/gate_test.go

@@ -0,0 +1,132 @@
+package payments
+
+import (
+	"slices"
+	"testing"
+)
+
+// allPresent is an account attached to every source (the maximal present set).
+var allPresent = []Source{SourceDirect, SourceVK, SourceTelegram}
+
+func TestSpendableSources(t *testing.T) {
+	tests := []struct {
+		name    string
+		ctx     Context
+		present []Source
+		want    []Source
+	}{
+		{"vk android, vk present", Context{Kind: SourceVK, Subtype: "android"}, allPresent, []Source{SourceVK}},
+		{"vk ios frozen", Context{Kind: SourceVK, Subtype: SubtypeIOS}, allPresent, nil},
+		{"vk android, vk absent", Context{Kind: SourceVK, Subtype: "android"}, []Source{SourceDirect}, nil},
+		{"telegram", Context{Kind: SourceTelegram, Subtype: "web"}, allPresent, []Source{SourceTelegram}},
+		{"telegram, tg absent", Context{Kind: SourceTelegram}, []Source{SourceVK}, nil},
+		{"direct all present, priority", Context{Kind: SourceDirect, Subtype: "web"}, allPresent, []Source{SourceDirect, SourceVK, SourceTelegram}},
+		{"direct, only vk+tg attached", Context{Kind: SourceDirect}, []Source{SourceTelegram, SourceVK}, []Source{SourceVK, SourceTelegram}},
+		{"direct, nothing attached", Context{Kind: SourceDirect}, nil, nil},
+		{"untrusted fail-closed", Context{}, allPresent, nil},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := spendableSources(tc.ctx, tc.present); !slices.Equal(got, tc.want) {
+				t.Errorf("spendableSources(%+v, %v) = %v, want %v", tc.ctx, tc.present, got, tc.want)
+			}
+		})
+	}
+}
+
+func TestApplicableOrigins(t *testing.T) {
+	tests := []struct {
+		name    string
+		ctx     Context
+		present []Source
+		want    []Source
+	}{
+		// A benefit still APPLIES on VK-iOS while spending is frozen.
+		{"vk ios still applies", Context{Kind: SourceVK, Subtype: SubtypeIOS}, allPresent, []Source{SourceVK}},
+		{"vk android", Context{Kind: SourceVK, Subtype: "android"}, allPresent, []Source{SourceVK}},
+		{"telegram", Context{Kind: SourceTelegram}, allPresent, []Source{SourceTelegram}},
+		{"direct all, priority", Context{Kind: SourceDirect}, allPresent, []Source{SourceDirect, SourceVK, SourceTelegram}},
+		{"untrusted fail-closed", Context{}, allPresent, nil},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := applicableOrigins(tc.ctx, tc.present); !slices.Equal(got, tc.want) {
+				t.Errorf("applicableOrigins(%+v, %v) = %v, want %v", tc.ctx, tc.present, got, tc.want)
+			}
+		})
+	}
+}
+
+// TestComplianceWall is the named unit-level compliance regression: a direct origin (externally
+// paid, outside any store cash desk) must NEVER be applicable inside a VK or TG wrapper, and no
+// segment is ever spendable there beyond the same-named one. The dangerous direction stays shut.
+func TestComplianceWall(t *testing.T) {
+	for _, kind := range []Source{SourceVK, SourceTelegram} {
+		for _, sub := range []string{"android", "ios", "web"} {
+			ctx := Context{Kind: kind, Subtype: sub}
+			if slices.Contains(applicableOrigins(ctx, allPresent), SourceDirect) {
+				t.Errorf("direct origin applies inside %s/%s — compliance wall breached", kind, sub)
+			}
+			for _, s := range spendableSources(ctx, allPresent) {
+				if s != kind {
+					t.Errorf("foreign segment %s spendable inside %s/%s", s, kind, sub)
+				}
+			}
+			// The opposite store's origin must not leak in either (vk⊥tg).
+			other := SourceVK
+			if kind == SourceVK {
+				other = SourceTelegram
+			}
+			if slices.Contains(applicableOrigins(ctx, allPresent), other) {
+				t.Errorf("%s origin applies inside %s — cross-store leak", other, kind)
+			}
+		}
+	}
+}
+
+func TestVisibleSources(t *testing.T) {
+	if got := visibleSources(Context{Kind: SourceVK, Subtype: SubtypeIOS}); !slices.Equal(got, []Source{SourceVK}) {
+		t.Errorf("VK visible = %v, want [vk] (direct/tg hidden in a store)", got)
+	}
+	if got := visibleSources(Context{Kind: SourceDirect}); !slices.Equal(got, allPresent) {
+		t.Errorf("direct visible = %v, want all three", got)
+	}
+	if got := visibleSources(Context{}); !slices.Equal(got, allPresent) {
+		t.Errorf("untrusted visible = %v, want all three (view-only)", got)
+	}
+}
+
+func TestSourceForIdentityKind(t *testing.T) {
+	tests := []struct {
+		kind string
+		want Source
+		ok   bool
+	}{
+		{"vk", SourceVK, true},
+		{"telegram", SourceTelegram, true},
+		{"email", SourceDirect, true},
+		{"robot", "", false},
+		{"unknown", "", false},
+	}
+	for _, tc := range tests {
+		got, ok := SourceForIdentityKind(tc.kind)
+		if got != tc.want || ok != tc.ok {
+			t.Errorf("SourceForIdentityKind(%q) = %q,%v want %q,%v", tc.kind, got, ok, tc.want, tc.ok)
+		}
+	}
+}
+
+func TestNewContextTrusted(t *testing.T) {
+	if c := NewContext("vk", "ios"); !c.Trusted() || !c.vkFrozen() {
+		t.Errorf("vk/ios: trusted=%v frozen=%v, want true/true", c.Trusted(), c.vkFrozen())
+	}
+	if c := NewContext("bogus", "web"); c.Trusted() {
+		t.Errorf("bogus kind should be untrusted")
+	}
+	if c := NewContext("", ""); c.Trusted() {
+		t.Errorf("empty kind should be untrusted")
+	}
+	if c := NewContext("direct", "web"); c.vkFrozen() {
+		t.Errorf("direct is never frozen")
+	}
+}

backend/internal/payments/money_test.go

@@ -0,0 +1,136 @@
+package payments
+
+import "testing"
+
+func TestMoneyFromMinor(t *testing.T) {
+	m, err := MoneyFromMinor(14950, CurrencyRUB)
+	if err != nil {
+		t.Fatalf("MoneyFromMinor: %v", err)
+	}
+	if m.Minor() != 14950 || m.Currency() != CurrencyRUB {
+		t.Fatalf("got minor=%d currency=%s", m.Minor(), m.Currency())
+	}
+	if _, err := MoneyFromMinor(1, Currency("EUR")); err == nil {
+		t.Fatal("expected an error for an unknown currency")
+	}
+}
+
+func TestMoneyFromMajor(t *testing.T) {
+	cases := []struct {
+		major int64
+		cur   Currency
+		minor int64
+	}{
+		{149, CurrencyRUB, 14900}, // roubles scale to kopecks
+		{250, CurrencyStar, 250},  // Stars are whole units
+		{7, CurrencyVote, 7},
+		{50, CurrencyChip, 50},
+	}
+	for _, c := range cases {
+		m, err := MoneyFromMajor(c.major, c.cur)
+		if err != nil {
+			t.Fatalf("MoneyFromMajor(%d,%s): %v", c.major, c.cur, err)
+		}
+		if m.Minor() != c.minor {
+			t.Errorf("MoneyFromMajor(%d,%s): minor=%d, want %d", c.major, c.cur, m.Minor(), c.minor)
+		}
+	}
+	if _, err := MoneyFromMajor(1<<62, CurrencyRUB); err == nil {
+		t.Fatal("expected an overflow error")
+	}
+}
+
+func TestParseMoneyExact(t *testing.T) {
+	cases := []struct {
+		text  string
+		cur   Currency
+		minor int64
+	}{
+		{"149.50", CurrencyRUB, 14950},
+		{"149", CurrencyRUB, 14900},
+		{"0.01", CurrencyRUB, 1},
+		{"0.10", CurrencyRUB, 10}, // 0.1 is inexact as a float; big.Rat keeps it exact
+		{"-5.00", CurrencyRUB, -500},
+		{"250", CurrencyStar, 250},
+		{"7", CurrencyVote, 7},
+		{"50", CurrencyChip, 50},
+	}
+	for _, c := range cases {
+		m, err := ParseMoney(c.text, c.cur)
+		if err != nil {
+			t.Fatalf("ParseMoney(%q,%s): %v", c.text, c.cur, err)
+		}
+		if m.Minor() != c.minor {
+			t.Errorf("ParseMoney(%q,%s): minor=%d, want %d", c.text, c.cur, m.Minor(), c.minor)
+		}
+	}
+}
+
+func TestParseMoneyRejectsFraction(t *testing.T) {
+	// A whole-unit currency (Vote/Star/chip) must never accept a fraction, and
+	// the rouble must never accept finer than a kopeck — the no-float gate.
+	bad := []struct {
+		text string
+		cur  Currency
+	}{
+		{"250.5", CurrencyStar},
+		{"1.5", CurrencyChip},
+		{"7.01", CurrencyVote},
+		{"1.999", CurrencyRUB},
+		{"0.001", CurrencyRUB},
+		{"abc", CurrencyRUB},
+		{"12.34", Currency("EUR")}, // unknown currency
+	}
+	for _, c := range bad {
+		if m, err := ParseMoney(c.text, c.cur); err == nil {
+			t.Errorf("ParseMoney(%q,%s) = %d, want an error", c.text, c.cur, m.Minor())
+		}
+	}
+}
+
+func TestMoneyAddCmp(t *testing.T) {
+	a, _ := MoneyFromMinor(14900, CurrencyRUB)
+	b, _ := MoneyFromMinor(50, CurrencyRUB)
+	sum, err := a.Add(b)
+	if err != nil || sum.Minor() != 14950 {
+		t.Fatalf("Add: minor=%d err=%v", sum.Minor(), err)
+	}
+	if c, err := a.Cmp(b); err != nil || c != 1 {
+		t.Fatalf("Cmp a>b: got %d err=%v", c, err)
+	}
+	if c, err := b.Cmp(a); err != nil || c != -1 {
+		t.Fatalf("Cmp b<a: got %d err=%v", c, err)
+	}
+	if c, err := a.Cmp(a); err != nil || c != 0 {
+		t.Fatalf("Cmp a==a: got %d err=%v", c, err)
+	}
+	// Cross-currency arithmetic is refused, not silently coerced.
+	star, _ := MoneyFromMinor(1, CurrencyStar)
+	if _, err := a.Add(star); err == nil {
+		t.Error("Add across currencies: expected an error")
+	}
+	if _, err := a.Cmp(star); err == nil {
+		t.Error("Cmp across currencies: expected an error")
+	}
+}
+
+func TestMoneyString(t *testing.T) {
+	cases := []struct {
+		minor int64
+		cur   Currency
+		want  string
+	}{
+		{14900, CurrencyRUB, "149.00 RUB"},
+		{14950, CurrencyRUB, "149.50 RUB"},
+		{1, CurrencyRUB, "0.01 RUB"},
+		{-500, CurrencyRUB, "-5.00 RUB"},
+		{250, CurrencyStar, "250 XTR"},
+		{5, CurrencyChip, "5 CHIP"},
+	}
+	for _, c := range cases {
+		m, _ := MoneyFromMinor(c.minor, c.cur)
+		if got := m.String(); got != c.want {
+			t.Errorf("Money{%d,%s}.String() = %q, want %q", c.minor, c.cur, got, c.want)
+		}
+	}
+}

backend/internal/payments/payments.go

@@ -0,0 +1,171 @@
+// Package payments is the in-game currency, wallet, benefit and catalog domain.
+//
+// It owns its own Postgres schema (payments) and is the only backend package
+// that issues SQL against it — an import-boundary test forbids any other package
+// from importing the payments jet code, which keeps the domain extractable into
+// its own database or process later. There is no cross-schema foreign key to the
+// account schema: an account id is a plain uuid here, kept referentially honest
+// in code.
+//
+// Money is carried exclusively by [Money] — an exact integer amount in a
+// currency's minor units — so no floating-point value ever reaches a monetary
+// amount, and a whole-unit currency (Vote, Star, chip) can never hold a
+// fraction. This file is the data-foundation layer: the currency value type; the
+// wallet mechanics build on the schema and this package later.
+package payments
+
+import (
+	"fmt"
+	"math/big"
+)
+
+// Currency identifies the unit a monetary amount is denominated in.
+type Currency string
+
+const (
+	// CurrencyRUB is the Russian rouble; its minor unit is the kopeck (1/100).
+	CurrencyRUB Currency = "RUB"
+	// CurrencyVote is the VK Vote — a whole unit with no sub-unit.
+	CurrencyVote Currency = "VOTE"
+	// CurrencyStar is the Telegram Star (XTR) — a whole unit with no sub-unit.
+	CurrencyStar Currency = "XTR"
+	// CurrencyChip is the in-game chip, the unit a value's price is quoted in —
+	// a whole unit with no sub-unit.
+	CurrencyChip Currency = "CHIP"
+)
+
+// minorPerUnit reports how many minor units make one major unit of the currency.
+// Every currency except the rouble is a whole-unit currency (scale 1), so an
+// amount in it structurally cannot carry a fraction.
+func (c Currency) minorPerUnit() int64 {
+	if c == CurrencyRUB {
+		return 100
+	}
+	return 1
+}
+
+// Valid reports whether the currency is one of the known units.
+func (c Currency) Valid() bool {
+	switch c {
+	case CurrencyRUB, CurrencyVote, CurrencyStar, CurrencyChip:
+		return true
+	default:
+		return false
+	}
+}
+
+// Money is an exact monetary amount: a signed integer count of a currency's
+// minor units (rouble kopecks; Vote/Star/chip whole units). It is the sole
+// carrier of money in the payments domain — construction, arithmetic and
+// formatting all go through it, so no float ever reaches an amount and a
+// whole-unit currency can never hold a fraction. The zero value has an empty,
+// invalid currency; build a value with [MoneyFromMinor], [MoneyFromMajor] or
+// [ParseMoney].
+type Money struct {
+	minor    int64
+	currency Currency
+}
+
+// MoneyFromMinor builds a Money from a raw count of the currency's minor units
+// (kopecks for the rouble, whole units otherwise). It errors on an unknown
+// currency.
+func MoneyFromMinor(minor int64, c Currency) (Money, error) {
+	if !c.Valid() {
+		return Money{}, fmt.Errorf("payments: unknown currency %q", c)
+	}
+	return Money{minor: minor, currency: c}, nil
+}
+
+// MoneyFromMajor builds a Money from a whole number of major units (roubles,
+// Votes, Stars, chips). It errors on an unknown currency or on overflow.
+func MoneyFromMajor(major int64, c Currency) (Money, error) {
+	if !c.Valid() {
+		return Money{}, fmt.Errorf("payments: unknown currency %q", c)
+	}
+	scaled := new(big.Int).Mul(big.NewInt(major), big.NewInt(c.minorPerUnit()))
+	if !scaled.IsInt64() {
+		return Money{}, fmt.Errorf("payments: %d %s overflows", major, c)
+	}
+	return Money{minor: scaled.Int64(), currency: c}, nil
+}
+
+// ParseMoney parses a decimal amount (e.g. "149.50", "250") in the currency,
+// exactly and without floating point (via math/big). It rejects a value with
+// finer precision than the currency allows — in particular, any fractional part
+// for a whole-unit currency — which is the gate that keeps a fraction out of an
+// integer currency.
+func ParseMoney(text string, c Currency) (Money, error) {
+	if !c.Valid() {
+		return Money{}, fmt.Errorf("payments: unknown currency %q", c)
+	}
+	r, ok := new(big.Rat).SetString(text)
+	if !ok {
+		return Money{}, fmt.Errorf("payments: %q is not a valid amount", text)
+	}
+	scaled := new(big.Rat).Mul(r, new(big.Rat).SetInt64(c.minorPerUnit()))
+	if !scaled.IsInt() {
+		return Money{}, fmt.Errorf("payments: %q has finer precision than %s allows", text, c)
+	}
+	num := scaled.Num() // the denominator is 1 once scaled to an integer
+	if !num.IsInt64() {
+		return Money{}, fmt.Errorf("payments: %q overflows %s", text, c)
+	}
+	return Money{minor: num.Int64(), currency: c}, nil
+}
+
+// Minor returns the amount as a count of the currency's minor units — the value
+// persisted to an amount column.
+func (m Money) Minor() int64 { return m.minor }
+
+// Currency returns the amount's currency.
+func (m Money) Currency() Currency { return m.currency }
+
+// IsZero reports whether the amount is zero.
+func (m Money) IsZero() bool { return m.minor == 0 }
+
+// Add returns the sum of the two amounts. It errors when the currencies differ.
+func (m Money) Add(o Money) (Money, error) {
+	if m.currency != o.currency {
+		return Money{}, fmt.Errorf("payments: cannot add %s to %s", o.currency, m.currency)
+	}
+	return Money{minor: m.minor + o.minor, currency: m.currency}, nil
+}
+
+// Cmp compares the two amounts, returning -1, 0 or +1. It errors when the
+// currencies differ.
+func (m Money) Cmp(o Money) (int, error) {
+	if m.currency != o.currency {
+		return 0, fmt.Errorf("payments: cannot compare %s to %s", o.currency, m.currency)
+	}
+	switch {
+	case m.minor < o.minor:
+		return -1, nil
+	case m.minor > o.minor:
+		return 1, nil
+	default:
+		return 0, nil
+	}
+}
+
+// String renders the amount as "<value> <currency>", with the currency's
+// fractional digits and no floating point (e.g. "149.50 RUB", "250 XTR").
+func (m Money) String() string {
+	scale := m.currency.minorPerUnit()
+	if scale == 1 {
+		return fmt.Sprintf("%d %s", m.minor, m.currency)
+	}
+	neg := m.minor < 0
+	abs := m.minor
+	if neg {
+		abs = -abs
+	}
+	width := 0
+	for s := scale; s > 1; s /= 10 {
+		width++
+	}
+	sign := ""
+	if neg {
+		sign = "-"
+	}
+	return fmt.Sprintf("%s%d.%0*d %s", sign, abs/scale, width, abs%scale, m.currency)
+}

backend/internal/payments/service.go

@@ -0,0 +1,246 @@
+package payments
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+// Service is the payments domain's application layer — the narrow surface other domains depend
+// on, keeping the schema reachable through one seam. Every read/gate method takes the trusted
+// execution Context and the account's present identity sources (which segments are awake, §6);
+// payments holds no cross-schema identity knowledge, so the caller supplies present. Reads are
+// served from the store's in-process cache, so the steady-state hot path issues no query to the
+// payments schema.
+type Service struct {
+	store *Store
+	clock func() time.Time
+}
+
+// NewService constructs a Service over store with a wall-clock time source.
+func NewService(store *Store) *Service {
+	return &Service{store: store, clock: func() time.Time { return time.Now().UTC() }}
+}
+
+// Ping reports whether the payments schema is reachable.
+func (s *Service) Ping(ctx context.Context) error { return s.store.Ping(ctx) }
+
+// Wallet returns the read model for the account in the execution context: the segments visible
+// there (each with its chip count and whether it is spendable) plus the context-applicable
+// benefits. In a store context only the same-named segment is shown; on web/native or an
+// untrusted platform all attached segments are shown, spendable only when the gate allows.
+func (s *Service) Wallet(ctx context.Context, accountID uuid.UUID, cxt Context, present []Source) (WalletView, error) {
+	st, err := s.store.state(ctx, accountID)
+	if err != nil {
+		return WalletView{}, err
+	}
+	now := s.clock()
+	view := WalletView{Benefits: benefitView(st, cxt, present, now)}
+	spendable := spendableSources(cxt, present)
+	for _, src := range visibleSources(cxt) {
+		if !has(present, src) {
+			continue // only the account's own (attached) segments are shown
+		}
+		view.Segments = append(view.Segments, Segment{
+			Source:    src,
+			Chips:     st.chipsOf(src),
+			Spendable: has(spendable, src),
+		})
+	}
+	return view, nil
+}
+
+// Catalog returns the storefront for the execution context: every chip-priced value (shown in
+// every context) plus the chip packs priced in the context's payment method. It is read straight
+// from the catalog tables — small and rarely edited, so uncached. An untrusted context has no
+// method and so shows values only; buying is gate-checked on Spend regardless (fail-closed).
+func (s *Service) Catalog(ctx context.Context, cxt Context) (CatalogView, error) {
+	entries, err := s.store.loadCatalog(ctx)
+	if err != nil {
+		return CatalogView{}, err
+	}
+	return projectCatalog(entries, cxt), nil
+}
+
+// AdFree reports whether ads are suppressed for the account in the context: some origin
+// applicable there has an active no-ads term or the forever flag. Fail-closed on an untrusted
+// platform (no origin applies).
+func (s *Service) AdFree(ctx context.Context, accountID uuid.UUID, cxt Context, present []Source) (bool, error) {
+	st, err := s.store.state(ctx, accountID)
+	if err != nil {
+		return false, err
+	}
+	now := s.clock()
+	for _, o := range applicableOrigins(cxt, present) {
+		b := st.benefitOf(o)
+		if b.adsForever || (b.adsPaidUntil != nil && b.adsPaidUntil.After(now)) {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+// HintsAvailable returns how many hints the account can use in the context — the sum over the
+// applicable origins. Zero on an untrusted platform.
+func (s *Service) HintsAvailable(ctx context.Context, accountID uuid.UUID, cxt Context, present []Source) (int, error) {
+	st, err := s.store.state(ctx, accountID)
+	if err != nil {
+		return 0, err
+	}
+	total := 0
+	for _, o := range applicableOrigins(cxt, present) {
+		total += st.benefitOf(o).hints
+	}
+	return total, nil
+}
+
+// SpendHint consumes one hint from the first applicable origin that has one (priority
+// direct→vk→tg), returning whether a hint was spent. It spends nothing when no origin is
+// applicable (untrusted platform or no attached segment).
+func (s *Service) SpendHint(ctx context.Context, accountID uuid.UUID, cxt Context, present []Source) (bool, error) {
+	origins := applicableOrigins(cxt, present)
+	if len(origins) == 0 {
+		return false, nil
+	}
+	return s.store.consumeHint(ctx, accountID, origins, s.clock())
+}
+
+// Spend buys a chip-priced value: it gate-checks the context, draws the price across the
+// spendable segments by priority direct→vk→tg, and applies the benefit — atomically. The
+// benefit's origin is the purchase context. It fails closed on an untrusted or frozen platform
+// (ErrUntrusted) and on insufficient chips (ErrInsufficientChips).
+func (s *Service) Spend(ctx context.Context, accountID uuid.UUID, cxt Context, present []Source, productID uuid.UUID) error {
+	spendable := spendableSources(cxt, present)
+	if len(spendable) == 0 {
+		return ErrUntrusted // untrusted, frozen, or no attached segment — no spend
+	}
+	prod, err := s.store.loadProduct(ctx, productID)
+	if err != nil {
+		return err
+	}
+	st, err := s.store.state(ctx, accountID)
+	if err != nil {
+		return err
+	}
+	draws, ok := planDraws(st, spendable, prod.priceChips)
+	if !ok {
+		return ErrInsufficientChips
+	}
+	snapshot, err := marshalSnapshot(prod)
+	if err != nil {
+		return err
+	}
+	return s.store.spend(ctx, accountID, draws, cxt.Kind, productID, prod.delta, snapshot, s.clock())
+}
+
+// Grant applies a benefit to an origin as a zero-price sale — an admin_grant ledger row and the
+// benefit (hints, a no-ads term in whole days, or the forever flag). It never grants chips (no
+// balance is touched — D16), so its signature has no chip amount. The origin is the admin's
+// compliance choice.
+func (s *Service) Grant(ctx context.Context, accountID uuid.UUID, origin Source, hints, noAdsDays int, forever bool) error {
+	if !origin.Valid() {
+		return fmt.Errorf("payments: invalid grant origin %q", origin)
+	}
+	d := benefitDelta{hintsAdd: hints, noAdsDays: noAdsDays, forever: forever}
+	if d.zero() {
+		return fmt.Errorf("payments: empty grant")
+	}
+	snapshot, err := marshalGrant(d)
+	if err != nil {
+		return err
+	}
+	return s.store.grant(ctx, accountID, origin, d, snapshot, s.clock())
+}
+
+// MergeTx merges the secondary account's segments and benefits into the primary inside the
+// caller's transaction (the account-merge flow). The caller invalidates the affected caches
+// after committing (Invalidate).
+func (s *Service) MergeTx(ctx context.Context, tx *sql.Tx, primary, secondary uuid.UUID) error {
+	return s.store.MergeTx(ctx, tx, primary, secondary, s.clock())
+}
+
+// Invalidate drops the cached state of the listed accounts (called after a merge commit).
+func (s *Service) Invalidate(ids ...uuid.UUID) { s.store.Invalidate(ids...) }
+
+// benefitView aggregates the benefits applicable in the context into the wallet view: ads-off
+// forever if any applicable origin is perpetual, else the latest active term end, plus the total
+// available hints.
+func benefitView(st walletState, cxt Context, present []Source, now time.Time) BenefitView {
+	var v BenefitView
+	for _, o := range applicableOrigins(cxt, present) {
+		b := st.benefitOf(o)
+		if b.adsForever {
+			v.AdsForever = true
+		}
+		if b.adsPaidUntil != nil && b.adsPaidUntil.After(now) {
+			if v.AdsPaidUntil == nil || b.adsPaidUntil.After(*v.AdsPaidUntil) {
+				v.AdsPaidUntil = b.adsPaidUntil
+			}
+		}
+		v.Hints += b.hints
+	}
+	return v
+}
+
+// planDraws greedily allocates price across the spendable segments in priority order, draining
+// each before moving on. It returns the per-segment draws and whether the segments together held
+// enough.
+func planDraws(st walletState, spendable []Source, price int) ([]sourceAmount, bool) {
+	remaining := price
+	var draws []sourceAmount
+	for _, src := range spendable {
+		if remaining <= 0 {
+			break
+		}
+		avail := st.chipsOf(src)
+		if avail <= 0 {
+			continue
+		}
+		take := min(avail, remaining)
+		draws = append(draws, sourceAmount{source: src, amount: take})
+		remaining -= take
+	}
+	if remaining > 0 {
+		return nil, false
+	}
+	return draws, true
+}
+
+// purchaseSnapshot is the catalog snapshot stored on a spend/grant ledger row, so history and
+// receipts stay independent of later catalog edits (§7/D34).
+type purchaseSnapshot struct {
+	ProductID  string         `json:"product_id,omitempty"`
+	Title      string         `json:"title,omitempty"`
+	Atoms      map[string]int `json:"atoms,omitempty"`
+	PriceChips int            `json:"price_chips"`
+	Forever    bool           `json:"forever,omitempty"`
+}
+
+// marshalSnapshot builds the snapshot for a chip spend.
+func marshalSnapshot(p catalogProduct) ([]byte, error) {
+	b, err := json.Marshal(purchaseSnapshot{ProductID: p.id.String(), Title: p.title, Atoms: p.atoms, PriceChips: p.priceChips})
+	if err != nil {
+		return nil, fmt.Errorf("payments: marshal snapshot: %w", err)
+	}
+	return b, nil
+}
+
+// marshalGrant builds the snapshot for an admin grant (price 0).
+func marshalGrant(d benefitDelta) ([]byte, error) {
+	atoms := map[string]int{}
+	if d.hintsAdd > 0 {
+		atoms["hints"] = d.hintsAdd
+	}
+	if d.noAdsDays > 0 {
+		atoms["noads_days"] = d.noAdsDays
+	}
+	b, err := json.Marshal(purchaseSnapshot{Atoms: atoms, PriceChips: 0, Forever: d.forever})
+	if err != nil {
+		return nil, fmt.Errorf("payments: marshal grant snapshot: %w", err)
+	}
+	return b, nil
+}

backend/internal/payments/store.go

@@ -0,0 +1,40 @@
+package payments
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+
+	"github.com/go-jet/jet/v2/postgres"
+
+	"scrabble/backend/internal/postgres/jet/payments/model"
+	"scrabble/backend/internal/postgres/jet/payments/table"
+)
+
+// Store is the Postgres-backed query surface for the payments schema. It is the
+// only place in the backend that issues SQL against payments.* (an
+// import-boundary test enforces it), so the domain stays extractable into its
+// own database. It fronts the materialized balances/benefits tables with an
+// in-process write-through cache (see cache.go) so hot reads issue no query on
+// the steady-state path.
+type Store struct {
+	db    *sql.DB
+	cache *walletCache
+}
+
+// NewStore constructs a Store wrapping db, with an empty read cache.
+func NewStore(db *sql.DB) *Store { return &Store{db: db, cache: newWalletCache()} }
+
+// Ping verifies the payments schema is reachable by reading the singleton config
+// row. It is the data-foundation health check; the wallet query surface arrives
+// with the currency mechanics.
+func (s *Store) Ping(ctx context.Context) error {
+	var row model.Config
+	if err := postgres.SELECT(table.Config.AllColumns).
+		FROM(table.Config).
+		LIMIT(1).
+		QueryContext(ctx, s.db, &row); err != nil {
+		return fmt.Errorf("payments: ping: %w", err)
+	}
+	return nil
+}

backend/internal/payments/store_catalog.go

@@ -0,0 +1,89 @@
+package payments
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/go-jet/jet/v2/postgres"
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/postgres/jet/payments/model"
+	"scrabble/backend/internal/postgres/jet/payments/table"
+)
+
+// atomQty is one atom line of a product as loaded from the catalog: the atom type and quantity.
+type atomQty struct {
+	atomType string
+	quantity int
+}
+
+// priceRow is one price of a product as loaded from the catalog: the payment method (empty for a
+// value's CHIP price, stored with a NULL method) and the amount in that currency's minor units.
+type priceRow struct {
+	method   string
+	currency Currency
+	amount   int64
+}
+
+// catalogEntry is a raw active product loaded for the storefront: its atom composition and every
+// price row. [projectCatalog] turns it into the context-visible [CatalogProduct].
+type catalogEntry struct {
+	id     uuid.UUID
+	title  string
+	atoms  []atomQty
+	prices []priceRow
+}
+
+// loadCatalog reads every active product with its atoms and prices, ordered by creation, straight
+// from the catalog tables. The catalog is small and rarely edited (admin console only), so it is
+// read uncached — unlike the per-account balances/benefits the read cache fronts.
+func (s *Store) loadCatalog(ctx context.Context) ([]catalogEntry, error) {
+	var prods []model.Product
+	if err := postgres.SELECT(table.Product.AllColumns).
+		FROM(table.Product).
+		WHERE(table.Product.Active.IS_TRUE()).
+		ORDER_BY(table.Product.CreatedAt.ASC()).
+		QueryContext(ctx, s.db, &prods); err != nil {
+		return nil, fmt.Errorf("payments: load catalog products: %w", err)
+	}
+	if len(prods) == 0 {
+		return nil, nil
+	}
+	entries := make([]catalogEntry, len(prods))
+	index := make(map[uuid.UUID]int, len(prods))
+	for i, p := range prods {
+		entries[i] = catalogEntry{id: p.ProductID, title: p.Title}
+		index[p.ProductID] = i
+	}
+
+	var items []model.ProductItem
+	if err := postgres.SELECT(table.ProductItem.AllColumns).
+		FROM(table.ProductItem).
+		QueryContext(ctx, s.db, &items); err != nil {
+		return nil, fmt.Errorf("payments: load catalog items: %w", err)
+	}
+	for _, it := range items {
+		if i, ok := index[it.ProductID]; ok {
+			entries[i].atoms = append(entries[i].atoms, atomQty{atomType: it.AtomType, quantity: int(it.Quantity)})
+		}
+	}
+
+	var prices []model.ProductPrice
+	if err := postgres.SELECT(table.ProductPrice.AllColumns).
+		FROM(table.ProductPrice).
+		QueryContext(ctx, s.db, &prices); err != nil {
+		return nil, fmt.Errorf("payments: load catalog prices: %w", err)
+	}
+	for _, pr := range prices {
+		i, ok := index[pr.ProductID]
+		if !ok {
+			continue // a price for a deactivated product — not in the storefront
+		}
+		method := ""
+		if pr.Method != nil {
+			method = *pr.Method
+		}
+		entries[i].prices = append(entries[i].prices, priceRow{method: method, currency: Currency(pr.Currency), amount: pr.Amount})
+	}
+	return entries, nil
+}

backend/internal/payments/store_wallet.go

@@ -0,0 +1,421 @@
+package payments
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/go-jet/jet/v2/postgres"
+	"github.com/go-jet/jet/v2/qrm"
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/postgres/jet/payments/model"
+	"scrabble/backend/internal/postgres/jet/payments/table"
+)
+
+// Domain errors surfaced by the payments store and service.
+var (
+	// ErrInsufficientChips means the spendable segments held fewer chips than the price.
+	ErrInsufficientChips = errors.New("payments: insufficient chips")
+	// ErrUntrusted means the platform context is untrusted, so the gate is fail-closed.
+	ErrUntrusted = errors.New("payments: untrusted platform")
+	// ErrProductNotFound means the product is absent or deactivated.
+	ErrProductNotFound = errors.New("payments: product not found")
+	// ErrNotAValue means the product has no chip price (it is a chip pack or unpriced), so it
+	// cannot be bought with chips.
+	ErrNotAValue = errors.New("payments: product is not a chip-priced value")
+)
+
+// withTx runs fn inside a transaction on db, rolling back on error or panic.
+func withTx(ctx context.Context, db *sql.DB, fn func(*sql.Tx) error) (err error) {
+	tx, err := db.BeginTx(ctx, nil)
+	if err != nil {
+		return fmt.Errorf("payments: begin tx: %w", err)
+	}
+	defer func() {
+		if p := recover(); p != nil {
+			_ = tx.Rollback()
+			panic(p)
+		}
+	}()
+	if err := fn(tx); err != nil {
+		_ = tx.Rollback()
+		return err
+	}
+	if err := tx.Commit(); err != nil {
+		return fmt.Errorf("payments: commit tx: %w", err)
+	}
+	return nil
+}
+
+// sourceAmount is one chip draw from a single segment during a spend.
+type sourceAmount struct {
+	source Source
+	amount int
+}
+
+// catalogProduct is a product resolved for a chip spend: its chip price, the benefit its atoms
+// fold into, and the raw atom composition for the purchase snapshot.
+type catalogProduct struct {
+	id         uuid.UUID
+	title      string
+	priceChips int
+	delta      benefitDelta
+	atoms      map[string]int
+}
+
+// loadState reads an account's balances and benefits straight from the materialized tables.
+func (s *Store) loadState(ctx context.Context, accountID uuid.UUID) (walletState, error) {
+	st := walletState{chips: map[Source]int{}, benefits: map[Source]benefitState{}}
+	var brows []model.Balances
+	if err := postgres.SELECT(table.Balances.AllColumns).
+		FROM(table.Balances).
+		WHERE(table.Balances.AccountID.EQ(postgres.UUID(accountID))).
+		QueryContext(ctx, s.db, &brows); err != nil {
+		return walletState{}, fmt.Errorf("payments: load balances %s: %w", accountID, err)
+	}
+	for _, r := range brows {
+		st.chips[Source(r.Source)] = int(r.Chips)
+	}
+	var frows []model.Benefits
+	if err := postgres.SELECT(table.Benefits.AllColumns).
+		FROM(table.Benefits).
+		WHERE(table.Benefits.AccountID.EQ(postgres.UUID(accountID))).
+		QueryContext(ctx, s.db, &frows); err != nil {
+		return walletState{}, fmt.Errorf("payments: load benefits %s: %w", accountID, err)
+	}
+	for _, r := range frows {
+		st.benefits[Source(r.Origin)] = benefitState{adsPaidUntil: r.AdsPaidUntil, adsForever: r.AdsForever, hints: int(r.Hints)}
+	}
+	return st, nil
+}
+
+// state returns an account's payments state, served from the read cache when warm, otherwise
+// loaded from the materialized tables and cached. The returned maps are read-only.
+func (s *Store) state(ctx context.Context, accountID uuid.UUID) (walletState, error) {
+	if st, ok := s.cache.get(accountID); ok {
+		return st, nil
+	}
+	st, err := s.loadState(ctx, accountID)
+	if err != nil {
+		return walletState{}, err
+	}
+	s.cache.put(accountID, st)
+	return st, nil
+}
+
+// Invalidate drops the cached state of every listed account so the next read reloads it. It is
+// called after a committed mutation whose transaction the payments package does not own — the
+// account-merge flow (after its own commit) and, later, external fund/refund intake.
+func (s *Store) Invalidate(ids ...uuid.UUID) {
+	for _, id := range ids {
+		s.cache.invalidate(id)
+	}
+}
+
+// loadProduct resolves a chip-priced value: an active product with a CHIP price row
+// (method NULL) whose atoms are benefits (hints / no-ads days). It rejects a missing or
+// deactivated product (ErrProductNotFound), a product with no chip price (ErrNotAValue), and a
+// product carrying the chips atom (a chip pack is funded, never bought with chips — ErrNotAValue).
+func (s *Store) loadProduct(ctx context.Context, productID uuid.UUID) (catalogProduct, error) {
+	var p model.Product
+	err := postgres.SELECT(table.Product.AllColumns).
+		FROM(table.Product).
+		WHERE(table.Product.ProductID.EQ(postgres.UUID(productID))).
+		LIMIT(1).
+		QueryContext(ctx, s.db, &p)
+	if errors.Is(err, qrm.ErrNoRows) || (err == nil && !p.Active) {
+		return catalogProduct{}, ErrProductNotFound
+	}
+	if err != nil {
+		return catalogProduct{}, fmt.Errorf("payments: load product %s: %w", productID, err)
+	}
+
+	var price model.ProductPrice
+	err = postgres.SELECT(table.ProductPrice.AllColumns).
+		FROM(table.ProductPrice).
+		WHERE(table.ProductPrice.ProductID.EQ(postgres.UUID(productID)).
+			AND(table.ProductPrice.Method.IS_NULL()).
+			AND(table.ProductPrice.Currency.EQ(postgres.String(string(CurrencyChip))))).
+		LIMIT(1).
+		QueryContext(ctx, s.db, &price)
+	if errors.Is(err, qrm.ErrNoRows) {
+		return catalogProduct{}, ErrNotAValue
+	}
+	if err != nil {
+		return catalogProduct{}, fmt.Errorf("payments: load price %s: %w", productID, err)
+	}
+
+	var items []model.ProductItem
+	if err := postgres.SELECT(table.ProductItem.AllColumns).
+		FROM(table.ProductItem).
+		WHERE(table.ProductItem.ProductID.EQ(postgres.UUID(productID))).
+		QueryContext(ctx, s.db, &items); err != nil {
+		return catalogProduct{}, fmt.Errorf("payments: load items %s: %w", productID, err)
+	}
+
+	cp := catalogProduct{id: productID, title: p.Title, priceChips: int(price.Amount), atoms: map[string]int{}}
+	for _, it := range items {
+		cp.atoms[it.AtomType] = int(it.Quantity)
+		switch it.AtomType {
+		case "hints":
+			cp.delta.hintsAdd += int(it.Quantity)
+		case "noads_days":
+			cp.delta.noAdsDays += int(it.Quantity)
+		case "chips":
+			return catalogProduct{}, ErrNotAValue // a value never grants chips
+		}
+	}
+	return cp, nil
+}
+
+// stackNoAds returns the new no-ads term end after adding addDays whole days from
+// max(now, current end) — terms add up, the remainder is never lost (§5/D33). A non-positive
+// addDays leaves the term unchanged; a nil current means no term yet.
+func stackNoAds(current *time.Time, addDays int, now time.Time) *time.Time {
+	if addDays <= 0 {
+		return current
+	}
+	base := now
+	if current != nil && current.After(now) {
+		base = *current
+	}
+	end := base.Add(time.Duration(addDays) * 24 * time.Hour)
+	return &end
+}
+
+// combineNoAds folds secondary's remaining no-ads term onto primary's during a merge: the
+// remaining duration of each is preserved (§6/D15 "terms extend per origin").
+func combineNoAds(primary, secondary *time.Time, now time.Time) *time.Time {
+	if secondary == nil || !secondary.After(now) {
+		return primary
+	}
+	base := now
+	if primary != nil && primary.After(now) {
+		base = *primary
+	}
+	end := base.Add(secondary.Sub(now))
+	return &end
+}
+
+// applyBenefitTx applies a benefit delta to one origin inside tx, stacking the no-ads term,
+// OR-ing the forever flag and adding hints. It ensures the (account, origin) row exists, locks
+// it, then writes the recomputed values — so concurrent applies serialise on the row lock.
+func applyBenefitTx(ctx context.Context, tx *sql.Tx, accountID uuid.UUID, origin Source, d benefitDelta, now time.Time) error {
+	if d.zero() {
+		return nil
+	}
+	if _, err := tx.ExecContext(ctx,
+		`INSERT INTO payments.benefits (account_id, origin) VALUES ($1, $2) ON CONFLICT DO NOTHING`,
+		accountID, string(origin)); err != nil {
+		return fmt.Errorf("payments: ensure benefit row %s: %w", origin, err)
+	}
+	var untilCur *time.Time
+	var foreverCur bool
+	var hintsCur int32
+	if err := tx.QueryRowContext(ctx,
+		`SELECT ads_paid_until, ads_forever, hints FROM payments.benefits
+		 WHERE account_id = $1 AND origin = $2 FOR UPDATE`, accountID, string(origin)).
+		Scan(&untilCur, &foreverCur, &hintsCur); err != nil {
+		return fmt.Errorf("payments: lock benefit %s: %w", origin, err)
+	}
+	if _, err := tx.ExecContext(ctx,
+		`UPDATE payments.benefits SET ads_paid_until = $3, ads_forever = $4, hints = $5, updated_at = now()
+		 WHERE account_id = $1 AND origin = $2`,
+		accountID, string(origin), stackNoAds(untilCur, d.noAdsDays, now), foreverCur || d.forever, int(hintsCur)+d.hintsAdd); err != nil {
+		return fmt.Errorf("payments: apply benefit %s: %w", origin, err)
+	}
+	return nil
+}
+
+// insertLedgerTx appends one append-only ledger row inside tx.
+func insertLedgerTx(ctx context.Context, tx *sql.Tx, accountID uuid.UUID, kind string, source, origin *Source, chipsDelta int, productID *uuid.UUID, snapshot []byte, now time.Time) error {
+	id, err := uuid.NewV7()
+	if err != nil {
+		return fmt.Errorf("payments: ledger id: %w", err)
+	}
+	// The snapshot is a bare value, not a postgres.String literal: a jsonb column infers its
+	// type from an untyped parameter (the game-moves payload idiom), whereas a text-typed
+	// literal is rejected against jsonb.
+	var snap any = postgres.NULL
+	if snapshot != nil {
+		snap = string(snapshot)
+	}
+	stmt := table.Ledger.INSERT(
+		table.Ledger.LedgerID, table.Ledger.AccountID, table.Ledger.Kind,
+		table.Ledger.Source, table.Ledger.Origin, table.Ledger.ChipsDelta,
+		table.Ledger.ProductID, table.Ledger.Snapshot, table.Ledger.CreatedAt,
+	).VALUES(
+		id, accountID, kind,
+		sourceOrNull(source), sourceOrNull(origin), int32(chipsDelta),
+		uuidOrNull(productID), snap, now,
+	)
+	if _, err := stmt.ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("payments: insert %s ledger: %w", kind, err)
+	}
+	return nil
+}
+
+// spend draws the chips across the given segments, appends a spend ledger row per draw (carrying
+// the purchase snapshot), and applies the benefit — all in one transaction. It fails closed on
+// an insufficient balance (a guarded decrement), rolling everything back.
+func (s *Store) spend(ctx context.Context, accountID uuid.UUID, draws []sourceAmount, origin Source, productID uuid.UUID, d benefitDelta, snapshot []byte, now time.Time) error {
+	err := withTx(ctx, s.db, func(tx *sql.Tx) error {
+		for _, dr := range draws {
+			res, err := table.Balances.
+				UPDATE(table.Balances.Chips, table.Balances.UpdatedAt).
+				SET(table.Balances.Chips.SUB(postgres.Int(int64(dr.amount))), postgres.TimestampzT(now)).
+				WHERE(table.Balances.AccountID.EQ(postgres.UUID(accountID)).
+					AND(table.Balances.Source.EQ(postgres.String(string(dr.source)))).
+					AND(table.Balances.Chips.GT_EQ(postgres.Int(int64(dr.amount))))).
+				ExecContext(ctx, tx)
+			if err != nil {
+				return fmt.Errorf("payments: decrement %s: %w", dr.source, err)
+			}
+			if n, _ := res.RowsAffected(); n == 0 {
+				return ErrInsufficientChips
+			}
+			src := dr.source
+			if err := insertLedgerTx(ctx, tx, accountID, "spend", &src, &origin, -dr.amount, &productID, snapshot, now); err != nil {
+				return err
+			}
+		}
+		return applyBenefitTx(ctx, tx, accountID, origin, d, now)
+	})
+	if err != nil {
+		return err
+	}
+	s.cache.invalidate(accountID)
+	return nil
+}
+
+// grant records an admin_grant ledger row (price 0, no chips) and applies the granted benefit to
+// the chosen origin, in one transaction — a zero-price sale of a value.
+func (s *Store) grant(ctx context.Context, accountID uuid.UUID, origin Source, d benefitDelta, snapshot []byte, now time.Time) error {
+	err := withTx(ctx, s.db, func(tx *sql.Tx) error {
+		if err := insertLedgerTx(ctx, tx, accountID, "admin_grant", nil, &origin, 0, nil, snapshot, now); err != nil {
+			return err
+		}
+		return applyBenefitTx(ctx, tx, accountID, origin, d, now)
+	})
+	if err != nil {
+		return err
+	}
+	s.cache.invalidate(accountID)
+	return nil
+}
+
+// consumeHint decrements one hint from the first applicable origin (in the given priority order)
+// that has one, with a guarded update. It returns whether a hint was spent.
+func (s *Store) consumeHint(ctx context.Context, accountID uuid.UUID, origins []Source, now time.Time) (bool, error) {
+	for _, o := range origins {
+		res, err := table.Benefits.
+			UPDATE(table.Benefits.Hints, table.Benefits.UpdatedAt).
+			SET(table.Benefits.Hints.SUB(postgres.Int(1)), postgres.TimestampzT(now)).
+			WHERE(table.Benefits.AccountID.EQ(postgres.UUID(accountID)).
+				AND(table.Benefits.Origin.EQ(postgres.String(string(o)))).
+				AND(table.Benefits.Hints.GT(postgres.Int(0)))).
+			ExecContext(ctx, s.db)
+		if err != nil {
+			return false, fmt.Errorf("payments: consume hint %s: %w", o, err)
+		}
+		if n, _ := res.RowsAffected(); n > 0 {
+			s.cache.invalidate(accountID)
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+// MergeTx folds the secondary account's segments and benefits into the primary, by source and by
+// origin, inside the caller's transaction (the account-merge flow): chips sum, no-ads terms
+// extend per origin, forever OR-s, hints add. The secondary's payments rows are removed. The
+// caller invalidates the primary's cache after its own commit (Invalidate). It does not touch
+// the account schema — the JET import boundary stays intact, only the shared connection is used.
+func (s *Store) MergeTx(ctx context.Context, tx *sql.Tx, primary, secondary uuid.UUID, now time.Time) error {
+	if _, err := tx.ExecContext(ctx,
+		`INSERT INTO payments.balances (account_id, source, chips, updated_at)
+		 SELECT $1, source, chips, now() FROM payments.balances WHERE account_id = $2
+		 ON CONFLICT (account_id, source) DO UPDATE
+		   SET chips = payments.balances.chips + EXCLUDED.chips, updated_at = now()`,
+		primary, secondary); err != nil {
+		return fmt.Errorf("payments: merge balances: %w", err)
+	}
+	if _, err := tx.ExecContext(ctx, `DELETE FROM payments.balances WHERE account_id = $1`, secondary); err != nil {
+		return fmt.Errorf("payments: clear secondary balances: %w", err)
+	}
+
+	rows, err := tx.QueryContext(ctx,
+		`SELECT origin, ads_paid_until, ads_forever, hints FROM payments.benefits WHERE account_id = $1`, secondary)
+	if err != nil {
+		return fmt.Errorf("payments: read secondary benefits: %w", err)
+	}
+	type secBenefit struct {
+		origin  Source
+		until   *time.Time
+		forever bool
+		hints   int
+	}
+	var secs []secBenefit
+	for rows.Next() {
+		var b secBenefit
+		var o string
+		var h int32
+		if err := rows.Scan(&o, &b.until, &b.forever, &h); err != nil {
+			rows.Close()
+			return fmt.Errorf("payments: scan secondary benefit: %w", err)
+		}
+		b.origin, b.hints = Source(o), int(h)
+		secs = append(secs, b)
+	}
+	if err := rows.Err(); err != nil {
+		rows.Close()
+		return fmt.Errorf("payments: iterate secondary benefits: %w", err)
+	}
+	rows.Close()
+
+	for _, b := range secs {
+		if _, err := tx.ExecContext(ctx,
+			`INSERT INTO payments.benefits (account_id, origin) VALUES ($1, $2) ON CONFLICT DO NOTHING`,
+			primary, string(b.origin)); err != nil {
+			return fmt.Errorf("payments: ensure primary benefit %s: %w", b.origin, err)
+		}
+		var untilCur *time.Time
+		var foreverCur bool
+		var hintsCur int32
+		if err := tx.QueryRowContext(ctx,
+			`SELECT ads_paid_until, ads_forever, hints FROM payments.benefits
+			 WHERE account_id = $1 AND origin = $2 FOR UPDATE`, primary, string(b.origin)).
+			Scan(&untilCur, &foreverCur, &hintsCur); err != nil {
+			return fmt.Errorf("payments: lock primary benefit %s: %w", b.origin, err)
+		}
+		if _, err := tx.ExecContext(ctx,
+			`UPDATE payments.benefits SET ads_paid_until = $3, ads_forever = $4, hints = $5, updated_at = now()
+			 WHERE account_id = $1 AND origin = $2`,
+			primary, string(b.origin), combineNoAds(untilCur, b.until, now), foreverCur || b.forever, int(hintsCur)+b.hints); err != nil {
+			return fmt.Errorf("payments: merge benefit %s: %w", b.origin, err)
+		}
+	}
+	if _, err := tx.ExecContext(ctx, `DELETE FROM payments.benefits WHERE account_id = $1`, secondary); err != nil {
+		return fmt.Errorf("payments: clear secondary benefits: %w", err)
+	}
+	return nil
+}
+
+// sourceOrNull renders an optional source as a SQL string or NULL.
+func sourceOrNull(s *Source) postgres.Expression {
+	if s == nil {
+		return postgres.NULL
+	}
+	return postgres.String(string(*s))
+}
+
+// uuidOrNull renders an optional id as a SQL uuid or NULL.
+func uuidOrNull(id *uuid.UUID) postgres.Expression {
+	if id == nil {
+		return postgres.NULL
+	}
+	return postgres.UUID(*id)
+}

backend/internal/payments/wallet_test.go

@@ -0,0 +1,182 @@
+package payments
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+// base is a fixed clock instant for the deterministic tests.
+var base = time.Date(2026, 7, 8, 12, 0, 0, 0, time.UTC)
+
+// seededService builds a Service whose read cache already holds st for id, so the read methods
+// resolve without a database (the store's db is nil). The clock is pinned to base.
+func seededService(id uuid.UUID, st walletState) *Service {
+	store := NewStore(nil)
+	store.cache.put(id, st)
+	return &Service{store: store, clock: func() time.Time { return base }}
+}
+
+func TestStackNoAds(t *testing.T) {
+	future := base.Add(48 * time.Hour)
+	past := base.Add(-time.Hour)
+	tests := []struct {
+		name    string
+		current *time.Time
+		addDays int
+		want    *time.Time
+	}{
+		{"fresh term", nil, 3, new(base.Add(72 * time.Hour))},
+		{"stack onto future", new(future), 2, new(future.Add(48 * time.Hour))},
+		{"lapsed term restarts from now", new(past), 1, new(base.Add(24 * time.Hour))},
+		{"zero days unchanged", new(future), 0, new(future)},
+		{"zero days, nil stays nil", nil, 0, nil},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := stackNoAds(tc.current, tc.addDays, base)
+			if (got == nil) != (tc.want == nil) || (got != nil && !got.Equal(*tc.want)) {
+				t.Errorf("stackNoAds = %v, want %v", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestCombineNoAds(t *testing.T) {
+	pFuture := base.Add(24 * time.Hour)
+	sFuture := base.Add(72 * time.Hour) // 3 days remaining
+	// primary future + secondary future: primary end + secondary's remaining (72h).
+	if got := combineNoAds(new(pFuture), new(sFuture), base); !got.Equal(pFuture.Add(72 * time.Hour)) {
+		t.Errorf("combine both future = %v, want %v", got, pFuture.Add(72*time.Hour))
+	}
+	// primary nil + secondary future: now + secondary's remaining.
+	if got := combineNoAds(nil, new(sFuture), base); !got.Equal(base.Add(72 * time.Hour)) {
+		t.Errorf("combine nil primary = %v, want %v", got, base.Add(72*time.Hour))
+	}
+	// secondary lapsed: primary unchanged.
+	if got := combineNoAds(new(pFuture), new(base.Add(-time.Hour)), base); !got.Equal(pFuture) {
+		t.Errorf("combine lapsed secondary = %v, want %v", got, pFuture)
+	}
+	// secondary nil: primary unchanged.
+	if got := combineNoAds(new(pFuture), nil, base); !got.Equal(pFuture) {
+		t.Errorf("combine nil secondary = %v, want %v", got, pFuture)
+	}
+}
+
+func TestPlanDraws(t *testing.T) {
+	st := walletState{chips: map[Source]int{SourceDirect: 30, SourceVK: 50, SourceTelegram: 5}}
+	// price met entirely by the first (direct) segment.
+	if draws, ok := planDraws(st, []Source{SourceDirect, SourceVK}, 20); !ok || len(draws) != 1 || draws[0] != (sourceAmount{SourceDirect, 20}) {
+		t.Errorf("single-segment draw = %v ok=%v", draws, ok)
+	}
+	// price spills from direct into vk by priority.
+	draws, ok := planDraws(st, []Source{SourceDirect, SourceVK, SourceTelegram}, 60)
+	want := []sourceAmount{{SourceDirect, 30}, {SourceVK, 30}}
+	if !ok || len(draws) != 2 || draws[0] != want[0] || draws[1] != want[1] {
+		t.Errorf("priority spill draw = %v ok=%v, want %v", draws, ok, want)
+	}
+	// insufficient total.
+	if _, ok := planDraws(st, []Source{SourceDirect, SourceVK, SourceTelegram}, 200); ok {
+		t.Error("expected insufficient")
+	}
+}
+
+func TestWalletSegments(t *testing.T) {
+	id := uuid.New()
+	st := walletState{chips: map[Source]int{SourceDirect: 100, SourceVK: 50}}
+	svc := seededService(id, st)
+	present := []Source{SourceDirect, SourceVK}
+
+	// Web/native: both attached segments shown, both spendable.
+	got, err := svc.Wallet(context.Background(), id, NewContext("direct", "web"), present)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(got.Segments) != 2 || !got.Segments[0].Spendable || got.Segments[0].Source != SourceDirect {
+		t.Errorf("direct wallet segments = %+v", got.Segments)
+	}
+	// VK Android: only vk shown, spendable.
+	got, _ = svc.Wallet(context.Background(), id, NewContext("vk", "android"), present)
+	if len(got.Segments) != 1 || got.Segments[0].Source != SourceVK || !got.Segments[0].Spendable {
+		t.Errorf("vk-android wallet = %+v", got.Segments)
+	}
+	// VK iOS: only vk shown, frozen (not spendable) but the balance is visible.
+	got, _ = svc.Wallet(context.Background(), id, NewContext("vk", "ios"), present)
+	if len(got.Segments) != 1 || got.Segments[0].Chips != 50 || got.Segments[0].Spendable {
+		t.Errorf("vk-ios wallet = %+v (want vk 50 frozen)", got.Segments)
+	}
+}
+
+func TestAdFreeByContext(t *testing.T) {
+	id := uuid.New()
+	future := base.Add(48 * time.Hour)
+	ctx := context.Background()
+
+	// A vk-origin no-ads term applies inside VK and out on web, but a direct-origin term never
+	// applies inside VK (the compliance wall).
+	svc := seededService(id, walletState{benefits: map[Source]benefitState{
+		SourceVK:     {adsPaidUntil: new(future)},
+		SourceDirect: {adsPaidUntil: new(future)},
+	}})
+	present := []Source{SourceDirect, SourceVK}
+
+	cases := []struct {
+		name string
+		cxt  Context
+		want bool
+	}{
+		{"vk term inside vk", NewContext("vk", "android"), true},
+		{"vk term inside vk-ios (applies while frozen)", NewContext("vk", "ios"), true},
+		{"terms on web", NewContext("direct", "web"), true},
+		{"untrusted fail-closed", NewContext("", ""), false},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got, err := svc.AdFree(ctx, id, tc.cxt, present)
+			if err != nil || got != tc.want {
+				t.Errorf("AdFree = %v (err %v), want %v", got, err, tc.want)
+			}
+		})
+	}
+
+	// Compliance: ONLY a direct-origin term, checked inside VK, must not suppress ads.
+	svc2 := seededService(id, walletState{benefits: map[Source]benefitState{SourceDirect: {adsPaidUntil: new(future)}}})
+	if got, _ := svc2.AdFree(ctx, id, NewContext("vk", "android"), present); got {
+		t.Error("direct-origin no-ads must NOT apply inside VK (compliance wall)")
+	}
+}
+
+func TestHintsAvailableByContext(t *testing.T) {
+	id := uuid.New()
+	svc := seededService(id, walletState{benefits: map[Source]benefitState{
+		SourceDirect: {hints: 3},
+		SourceVK:     {hints: 2},
+	}})
+	present := []Source{SourceDirect, SourceVK}
+	ctx := context.Background()
+
+	// Web: both applicable origins summed.
+	if n, _ := svc.HintsAvailable(ctx, id, NewContext("direct", "web"), present); n != 5 {
+		t.Errorf("web hints = %d, want 5", n)
+	}
+	// VK: only vk-origin hints.
+	if n, _ := svc.HintsAvailable(ctx, id, NewContext("vk", "android"), present); n != 2 {
+		t.Errorf("vk hints = %d, want 2", n)
+	}
+	// Untrusted: none.
+	if n, _ := svc.HintsAvailable(ctx, id, NewContext("", ""), present); n != 0 {
+		t.Errorf("untrusted hints = %d, want 0", n)
+	}
+}
+
+func TestSpendHintUntrustedNoOp(t *testing.T) {
+	id := uuid.New()
+	svc := seededService(id, walletState{benefits: map[Source]benefitState{SourceDirect: {hints: 3}}})
+	// Untrusted context: no applicable origin, so nothing is spent and the DB (nil) is never hit.
+	spent, err := svc.SpendHint(context.Background(), id, NewContext("", ""), []Source{SourceDirect})
+	if err != nil || spent {
+		t.Errorf("untrusted SpendHint = %v (err %v), want false", spent, err)
+	}
+}

backend/internal/postgres/jet/backend/model/accounts.go

@@ -32,4 +32,8 @@ type Accounts struct {
 	MergedAt               *time.Time
 	FlaggedHighRateAt      *time.Time
 	VariantPreferences     pq.StringArray
+	LastLoginAt            *time.Time
+	LastLoginIP            *string
+	DeletedAt              *time.Time
+	DeletedDisplayName     *string
 }

backend/internal/postgres/jet/backend/model/ad_campaigns.go

@@ -13,13 +13,20 @@ import (
 )
 
 type AdCampaigns struct {
-	CampaignID uuid.UUID `sql:"primary_key"`
-	Name       string
-	Weight     int32
-	IsDefault  bool
-	Enabled    bool
-	StartsAt   *time.Time
-	EndsAt     *time.Time
-	CreatedAt  time.Time
-	UpdatedAt  time.Time
+	CampaignID       uuid.UUID `sql:"primary_key"`
+	Name             string
+	Weight           int32
+	IsDefault        bool
+	Enabled          bool
+	StartsAt         *time.Time
+	EndsAt           *time.Time
+	CreatedAt        time.Time
+	UpdatedAt        time.Time
+	OverrideBg       *string
+	OverrideFg       *string
+	OverrideLink     *string
+	OverrideBgDark   *string
+	OverrideFgDark   *string
+	OverrideLinkDark *string
+	Urgent           bool
 }

backend/internal/postgres/jet/backend/model/email_confirmations.go

@@ -21,4 +21,6 @@ type EmailConfirmations struct {
 	Attempts       int16
 	ConsumedAt     *time.Time
 	CreatedAt      time.Time
+	Purpose        string
+	LinkTokenHash  *string
 }

backend/internal/postgres/jet/backend/model/feedback_messages.go

@@ -27,4 +27,6 @@ type FeedbackMessages struct {
 	ReplyReadAt    *time.Time
 	CreatedAt      time.Time
 	Lang           *string
+	AppVersion     *string
+	BrowserTz      *string
 }