Merge pull request 'feat(payments): payments schema, currency domain and money type' (#215) from feature/payments-data-foundation into development

The committed go-jet code had drifted from the schema: robot_blocks and
robot_friend_requests (created in the baseline) had no generated tables, the
feedback_messages model was missing app_version/browser_tz (added in 00003 and
00004), and UseSchema omitted account_best_move and the two robot tables.
Regenerate so the jet layer mirrors the migrations again.

Additive only — two nullable columns appended to feedback_messages plus two new
tables; the full build, vet, unit and integration suites stay green.

.gitea/workflows/ci.yaml

@@ -214,9 +214,21 @@ jobs:
         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:
@@ -252,6 +264,7 @@ jobs:
         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
@@ -271,6 +284,7 @@ jobs:
           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
@@ -302,9 +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:

PLAN.md

@@ -0,0 +1,620 @@
+# 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)); 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 | TODO |
+| E2 | Currency + benefit core | 1 | TODO |
+| E3 | Wallet UI | 1 | TODO |
+| E4 | Durability (PITR) | 2 | TODO |
+| 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) bool`, `SpendHint(ctx, account, platform) error`,
+  `Balances(ctx, account, platform) …`). Keep the surface small; this is the seam that lets
+  payments become a separate process later without touching callers.
+
+### 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:** TODO · **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 and re-confirmed each cold start. This is the foundation the gate
+(E2) stands on; without it the gate is meaningless.
+
+**Model.** `platform = {kind: vk|telegram|direct, subtype: ios|android|web}` becomes a
+property of the **session**. On cold start the client submits the fresh wrapper signature
+(VK launch-params `sign` / TG `initData`); the gateway (or backend session-resolve)
+validates it and records/refreshes the session's platform. `direct` needs no signature — it
+is implied by a web/native session's creation path.
+
+**Backend.**
+
+- Session store (`backend/internal/session/`): add `platform` (kind+subtype) to the session
+  row + `Session` struct; set it at creation and refresh it on a validated cold-start call.
+- Session resolve (`handlers_auth.go handleResolveSession` → `resolveResponse` DTO
+  `dto.go`): return `platform` so the gateway can carry it.
+- Validation: TG `initData` validator already exists (`platform/telegram/internal/initdata`)
+  — reuse. Add VK launch-params `sign` verification (HMAC over sorted params with the VK app
+  secret) — new small verifier, unit-tested against known VK vectors.
+- Gateway (`gateway/internal/backendclient`): inject a trusted `X-Platform` header (mirror
+  `X-User-ID` injection in `client.go do()`), sourced from the resolved session — never from
+  the client request body.
+- Backend middleware: read `X-Platform` into context alongside `X-User-ID`
+  (`middleware.go`); expose a typed accessor `platform(c)`.
+- **Fail-closed default:** absent/invalid/stale platform ⇒ context = untrusted; the payments
+  interface treats untrusted as "view only" (enforced in E2's gate, but the signal plumbing
+  lands here).
+
+**Client (`ui/`).** On cold start, submit the wrapper signature to the session-establish/
+refresh call: VK via `ui/src/lib/vk.ts` (launch params), TG via `ui/src/lib/telegram.ts`
+(`initData`). `direct` submits nothing (web/native). Compose the platform from
+`insideVK()` + `insideTelegram()` + `clientChannel()` + `vkPlatform()` (no single
+discriminator exists today — see `ui/src/lib/channel.ts`, note VK reads as `web` there).
+
+**Tests.**
+
+- unit (Go): VK sign verifier accepts valid / rejects tampered params; TG initData path
+  (existing) covered; platform kind+subtype derivation.
+- integration: session carries platform; resolve returns it; stale/absent → untrusted.
+- UI: cold start submits the right signature per wrapper (mock).
+
+**Done-criteria.** A VK/TG session resolves to a trusted `{kind,subtype}`; a forged body
+cannot change it; `direct` sessions resolve to `direct`; untrusted path is reachable and
+observable. No user-visible change.
+
+**Notes/risks.** VK iOS must surface as `subtype=ios` (drives the frozen state in E2/E3).
+Old sessions predating this stage have no platform → untrusted → fail-closed (acceptable;
+re-cold-start fixes it). Keep the VK app secret in config/secret store, not code.
+
+---
+
+## E2 — Currency + benefit core
+
+**Status:** TODO · **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).**
+
+- `Balances(ctx, account, platform)` → the segments spendable in the platform's context
+  (VK→vk; TG→tg; direct→direct+vk+tg; VK-iOS→frozen/view; untrusted→none).
+- `Spend(ctx, account, platform, productID)` → gate-checked purchase of a value with chips:
+  resolve spendable segments by context, draw by priority (direct→vk→tg on web), write a
+  `spend` ledger row + 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)` → `admin_grant` ledger row (price 0, concrete values
+  only, never chips), same benefit application; origin chosen by the admin (E7 UI; here the
+  service method + an internal/admin entrypoint).
+- `AdFree(ctx, account, platform)` / `HintsAvailable(ctx, account, platform)` /
+  `SpendHint(ctx, account, platform)` → 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.
+- `Merge` / `Unlink` hooks: extend `accountmerge` to merge segments+benefits by origin
+  (same-origin add, different coexist), and make segment availability follow identity
+  presence (unlink → sleep, re-link → wake). Warn-before-unlink is a UI concern (surface the
+  balance via the interface).
+
+**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); priority draw; no-ads
+  stacking (`+=` from max(now,end)) + forever override; per-origin hint applicability;
+  merge/unlink segment math.
+- 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.** With chips seeded via `admin_grant`, a user can buy no-ads/hints; the gate
+blocks cross-context spend and cross-origin application; ads gate reads the new benefit;
+`SpendHint` uses segments; 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:** TODO · **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.
+
+**UI (`ui/`).**
+
+- New `'wallet'` tab in `ui/src/screens/SettingsHub.svelte` — `SettingsTab` union, tab
+  button **between Friends (:65) and About (:66)**, body branch in the `:42-51` switch,
+  `'wallet'` route in `ui/src/lib/routeparse.ts` + `ui/src/App.svelte`. Reuse the hub's
+  guest/offline gating.
+- `Wallet.svelte` screen: **minimal** — context-available chip balances + active benefits
+  (no-ads until date, hints count). **No history feed** (PAYMENTS §11 — noise). Storefront:
+  products from the configurable catalog, prices in chips (values) / per-method (chip packs).
+- **Guest:** section hidden entirely (durable-only).
+- **GP build:** purchase CTA replaced by a stub ("install the RuStore build to make
+  purchases"); rewarded + spending earned chips still work. Detect the GP native build.
+- **Web-spend warning:** before spending vk/tg chips in a web/native (direct) context, show
+  an own `Modal` (not `showPopup` — that eats the user-activation gesture) warning the value
+  will be web/native-only.
+- Extract all logic into `ui/src/lib/*` (unit-testable); keep `.svelte` thin.
+
+**Tests.**
+
+- unit (vitest): storefront/price formatting, context-available-segment selection, warning
+  trigger condition.
+- UI (Playwright mock, Chromium+WebKit): Wallet renders between Friends/About; guest hides
+  it; GP stub; warning modal on web vk/tg spend. Mock overlay must stay instant under
+  `MODE==='mock'` (or it intercepts taps).
+
+**Done-criteria.** Owner can review the Wallet on the deployed test contour (visual sign-off
+is on the contour, not local); balances/benefits/storefront correct per context; guest/GP/
+warning paths verified. Release 1 is now demonstrable end-to-end via `admin_grant`.
+
+**Notes/risks.** No global `.btn`/`.ghost` in `ui/` — style per-component with scoped CSS +
+tokens (mirror NewGame `.invite` for a CTA). Svelte whitespace/`$state` naming gotchas
+apply. iOS WebView download/gesture caveats are irrelevant here (no file delivery).
+
+---
+
+## E4 — Durability (PITR)
+
+**Status:** TODO · **Release 2** · depends on: E0 (schema exists) · mechanics: PAYMENTS §14.
+
+**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.
+
+**Work.**
+
+- Add WAL archiving to the prod Postgres (pgBackRest or WAL-G): base backups + continuous
+  WAL to a second host or object storage. Wire into `deploy/` (compose/prod overlay +
+  ansible `deploy/ansible/`), config + secrets under the `PROD_` prefix.
+- Restore runbook in `deploy/README.md`: base + WAL replay to a timestamp; test the restore
+  on a scratch target.
+- Keep the existing migration-time `pg_dump` (`deploy/prod-deploy.sh`) as belt-and-braces.
+
+**Mandatory pre-prod assessment (owner-required, gates the Release 2 prod rollout).**
+Before the first money goes live, produce and record here:
+
+1. **Disk-storage cost estimate** for the WAL archive + base backups (retention window ×
+   WAL volume; account for both hosts / object-storage pricing). This can change hosting
+   sizing.
+2. **PG performance-degradation assessment** from continuous archiving (write amplification,
+   archive_command latency, backup I/O contention) on the prod-sized instance.
+
+Neither blocks building the plan, but both **must** be completed and reviewed before the
+prod release — surface the numbers to the owner (they may change host settings).
+
+**Tests.** Restore drill on a scratch instance (base + WAL → target timestamp) documented
+and passing. No app-level tests.
+
+**Done-criteria.** WAL archiving live on prod PG; a timed restore verified; cost + perf
+assessment recorded and owner-reviewed; runbook in `deploy/README.md`.
+
+**Notes/risks.** The tg host is weak (1 vCPU) — if the archive lands there, watch
+contention. 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`).
+- 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.

backend/cmd/backend/main.go

@@ -31,6 +31,7 @@ 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"
@@ -260,6 +261,15 @@ 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")
+
 	// 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
@@ -287,6 +297,7 @@ 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,

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/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/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

@@ -1058,10 +1058,31 @@ 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 {
@@ -1080,6 +1101,26 @@ func (svc *Service) Hint(ctx context.Context, gameID, accountID uuid.UUID) (Hint
 	if !pre.HintsAllowed {
 		return HintResult{}, ErrHintsDisabled
 	}
+	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
+	}
 	acc, err := svc.accounts.GetByID(ctx, accountID)
 	if err != nil {
 		return HintResult{}, err
@@ -1208,6 +1249,8 @@ 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
 }
 

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/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/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/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 +1,17 @@
+package payments
+
+import "context"
+
+// Service is the payments domain's application layer — the narrow surface other
+// domains depend on, keeping the schema reachable through one seam. The
+// data-foundation layer exposes only a health check; the wallet, benefit and
+// store-compliance operations arrive with the currency mechanics.
+type Service struct {
+	store *Store
+}
+
+// NewService constructs a Service over store.
+func NewService(store *Store) *Service { return &Service{store: store} }
+
+// Ping reports whether the payments schema is reachable.
+func (s *Service) Ping(ctx context.Context) error { return s.store.Ping(ctx) }

backend/internal/payments/store.go

@@ -0,0 +1,37 @@
+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.
+type Store struct {
+	db *sql.DB
+}
+
+// NewStore constructs a Store wrapping db.
+func NewStore(db *sql.DB) *Store { return &Store{db: db} }
+
+// 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/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
 }

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

@@ -0,0 +1,23 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package model
+
+import (
+	"github.com/google/uuid"
+	"time"
+)
+
+type RobotBlocks struct {
+	ID          uuid.UUID `sql:"primary_key"`
+	BlockerID   uuid.UUID
+	GameID      uuid.UUID
+	Seat        int16
+	RobotID     uuid.UUID
+	DisplayName string
+	CreatedAt   time.Time
+}

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

@@ -0,0 +1,23 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package model
+
+import (
+	"github.com/google/uuid"
+	"time"
+)
+
+type RobotFriendRequests struct {
+	ID          uuid.UUID `sql:"primary_key"`
+	RequesterID uuid.UUID
+	GameID      uuid.UUID
+	Seat        int16
+	RobotID     uuid.UUID
+	DisplayName string
+	CreatedAt   time.Time
+}

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

@@ -31,6 +31,8 @@ type feedbackMessagesTable struct {
 	ReplyReadAt    postgres.ColumnTimestampz
 	CreatedAt      postgres.ColumnTimestampz
 	Lang           postgres.ColumnString
+	AppVersion     postgres.ColumnString
+	BrowserTz      postgres.ColumnString
 
 	AllColumns     postgres.ColumnList
 	MutableColumns postgres.ColumnList
@@ -86,8 +88,10 @@ func newFeedbackMessagesTableImpl(schemaName, tableName, alias string) feedbackM
 		ReplyReadAtColumn    = postgres.TimestampzColumn("reply_read_at")
 		CreatedAtColumn      = postgres.TimestampzColumn("created_at")
 		LangColumn           = postgres.StringColumn("lang")
-		allColumns           = postgres.ColumnList{MessageIDColumn, AccountIDColumn, BodyColumn, AttachmentColumn, AttachmentNameColumn, SenderIPColumn, ChannelColumn, ReadAtColumn, ArchivedAtColumn, ReplyBodyColumn, RepliedAtColumn, ReplyReadAtColumn, CreatedAtColumn, LangColumn}
-		mutableColumns       = postgres.ColumnList{AccountIDColumn, BodyColumn, AttachmentColumn, AttachmentNameColumn, SenderIPColumn, ChannelColumn, ReadAtColumn, ArchivedAtColumn, ReplyBodyColumn, RepliedAtColumn, ReplyReadAtColumn, CreatedAtColumn, LangColumn}
+		AppVersionColumn     = postgres.StringColumn("app_version")
+		BrowserTzColumn      = postgres.StringColumn("browser_tz")
+		allColumns           = postgres.ColumnList{MessageIDColumn, AccountIDColumn, BodyColumn, AttachmentColumn, AttachmentNameColumn, SenderIPColumn, ChannelColumn, ReadAtColumn, ArchivedAtColumn, ReplyBodyColumn, RepliedAtColumn, ReplyReadAtColumn, CreatedAtColumn, LangColumn, AppVersionColumn, BrowserTzColumn}
+		mutableColumns       = postgres.ColumnList{AccountIDColumn, BodyColumn, AttachmentColumn, AttachmentNameColumn, SenderIPColumn, ChannelColumn, ReadAtColumn, ArchivedAtColumn, ReplyBodyColumn, RepliedAtColumn, ReplyReadAtColumn, CreatedAtColumn, LangColumn, AppVersionColumn, BrowserTzColumn}
 		defaultColumns       = postgres.ColumnList{CreatedAtColumn}
 	)
 
@@ -109,6 +113,8 @@ func newFeedbackMessagesTableImpl(schemaName, tableName, alias string) feedbackM
 		ReplyReadAt:    ReplyReadAtColumn,
 		CreatedAt:      CreatedAtColumn,
 		Lang:           LangColumn,
+		AppVersion:     AppVersionColumn,
+		BrowserTz:      BrowserTzColumn,
 
 		AllColumns:     allColumns,
 		MutableColumns: mutableColumns,

backend/internal/postgres/jet/backend/table/robot_blocks.go

@@ -0,0 +1,96 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package table
+
+import (
+	"github.com/go-jet/jet/v2/postgres"
+)
+
+var RobotBlocks = newRobotBlocksTable("backend", "robot_blocks", "")
+
+type robotBlocksTable struct {
+	postgres.Table
+
+	// Columns
+	ID          postgres.ColumnString
+	BlockerID   postgres.ColumnString
+	GameID      postgres.ColumnString
+	Seat        postgres.ColumnInteger
+	RobotID     postgres.ColumnString
+	DisplayName postgres.ColumnString
+	CreatedAt   postgres.ColumnTimestampz
+
+	AllColumns     postgres.ColumnList
+	MutableColumns postgres.ColumnList
+	DefaultColumns postgres.ColumnList
+}
+
+type RobotBlocksTable struct {
+	robotBlocksTable
+
+	EXCLUDED robotBlocksTable
+}
+
+// AS creates new RobotBlocksTable with assigned alias
+func (a RobotBlocksTable) AS(alias string) *RobotBlocksTable {
+	return newRobotBlocksTable(a.SchemaName(), a.TableName(), alias)
+}
+
+// Schema creates new RobotBlocksTable with assigned schema name
+func (a RobotBlocksTable) FromSchema(schemaName string) *RobotBlocksTable {
+	return newRobotBlocksTable(schemaName, a.TableName(), a.Alias())
+}
+
+// WithPrefix creates new RobotBlocksTable with assigned table prefix
+func (a RobotBlocksTable) WithPrefix(prefix string) *RobotBlocksTable {
+	return newRobotBlocksTable(a.SchemaName(), prefix+a.TableName(), a.TableName())
+}
+
+// WithSuffix creates new RobotBlocksTable with assigned table suffix
+func (a RobotBlocksTable) WithSuffix(suffix string) *RobotBlocksTable {
+	return newRobotBlocksTable(a.SchemaName(), a.TableName()+suffix, a.TableName())
+}
+
+func newRobotBlocksTable(schemaName, tableName, alias string) *RobotBlocksTable {
+	return &RobotBlocksTable{
+		robotBlocksTable: newRobotBlocksTableImpl(schemaName, tableName, alias),
+		EXCLUDED:         newRobotBlocksTableImpl("", "excluded", ""),
+	}
+}
+
+func newRobotBlocksTableImpl(schemaName, tableName, alias string) robotBlocksTable {
+	var (
+		IDColumn          = postgres.StringColumn("id")
+		BlockerIDColumn   = postgres.StringColumn("blocker_id")
+		GameIDColumn      = postgres.StringColumn("game_id")
+		SeatColumn        = postgres.IntegerColumn("seat")
+		RobotIDColumn     = postgres.StringColumn("robot_id")
+		DisplayNameColumn = postgres.StringColumn("display_name")
+		CreatedAtColumn   = postgres.TimestampzColumn("created_at")
+		allColumns        = postgres.ColumnList{IDColumn, BlockerIDColumn, GameIDColumn, SeatColumn, RobotIDColumn, DisplayNameColumn, CreatedAtColumn}
+		mutableColumns    = postgres.ColumnList{BlockerIDColumn, GameIDColumn, SeatColumn, RobotIDColumn, DisplayNameColumn, CreatedAtColumn}
+		defaultColumns    = postgres.ColumnList{CreatedAtColumn}
+	)
+
+	return robotBlocksTable{
+		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
+
+		//Columns
+		ID:          IDColumn,
+		BlockerID:   BlockerIDColumn,
+		GameID:      GameIDColumn,
+		Seat:        SeatColumn,
+		RobotID:     RobotIDColumn,
+		DisplayName: DisplayNameColumn,
+		CreatedAt:   CreatedAtColumn,
+
+		AllColumns:     allColumns,
+		MutableColumns: mutableColumns,
+		DefaultColumns: defaultColumns,
+	}
+}

backend/internal/postgres/jet/backend/table/robot_friend_requests.go

@@ -0,0 +1,96 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package table
+
+import (
+	"github.com/go-jet/jet/v2/postgres"
+)
+
+var RobotFriendRequests = newRobotFriendRequestsTable("backend", "robot_friend_requests", "")
+
+type robotFriendRequestsTable struct {
+	postgres.Table
+
+	// Columns
+	ID          postgres.ColumnString
+	RequesterID postgres.ColumnString
+	GameID      postgres.ColumnString
+	Seat        postgres.ColumnInteger
+	RobotID     postgres.ColumnString
+	DisplayName postgres.ColumnString
+	CreatedAt   postgres.ColumnTimestampz
+
+	AllColumns     postgres.ColumnList
+	MutableColumns postgres.ColumnList
+	DefaultColumns postgres.ColumnList
+}
+
+type RobotFriendRequestsTable struct {
+	robotFriendRequestsTable
+
+	EXCLUDED robotFriendRequestsTable
+}
+
+// AS creates new RobotFriendRequestsTable with assigned alias
+func (a RobotFriendRequestsTable) AS(alias string) *RobotFriendRequestsTable {
+	return newRobotFriendRequestsTable(a.SchemaName(), a.TableName(), alias)
+}
+
+// Schema creates new RobotFriendRequestsTable with assigned schema name
+func (a RobotFriendRequestsTable) FromSchema(schemaName string) *RobotFriendRequestsTable {
+	return newRobotFriendRequestsTable(schemaName, a.TableName(), a.Alias())
+}
+
+// WithPrefix creates new RobotFriendRequestsTable with assigned table prefix
+func (a RobotFriendRequestsTable) WithPrefix(prefix string) *RobotFriendRequestsTable {
+	return newRobotFriendRequestsTable(a.SchemaName(), prefix+a.TableName(), a.TableName())
+}
+
+// WithSuffix creates new RobotFriendRequestsTable with assigned table suffix
+func (a RobotFriendRequestsTable) WithSuffix(suffix string) *RobotFriendRequestsTable {
+	return newRobotFriendRequestsTable(a.SchemaName(), a.TableName()+suffix, a.TableName())
+}
+
+func newRobotFriendRequestsTable(schemaName, tableName, alias string) *RobotFriendRequestsTable {
+	return &RobotFriendRequestsTable{
+		robotFriendRequestsTable: newRobotFriendRequestsTableImpl(schemaName, tableName, alias),
+		EXCLUDED:                 newRobotFriendRequestsTableImpl("", "excluded", ""),
+	}
+}
+
+func newRobotFriendRequestsTableImpl(schemaName, tableName, alias string) robotFriendRequestsTable {
+	var (
+		IDColumn          = postgres.StringColumn("id")
+		RequesterIDColumn = postgres.StringColumn("requester_id")
+		GameIDColumn      = postgres.StringColumn("game_id")
+		SeatColumn        = postgres.IntegerColumn("seat")
+		RobotIDColumn     = postgres.StringColumn("robot_id")
+		DisplayNameColumn = postgres.StringColumn("display_name")
+		CreatedAtColumn   = postgres.TimestampzColumn("created_at")
+		allColumns        = postgres.ColumnList{IDColumn, RequesterIDColumn, GameIDColumn, SeatColumn, RobotIDColumn, DisplayNameColumn, CreatedAtColumn}
+		mutableColumns    = postgres.ColumnList{RequesterIDColumn, GameIDColumn, SeatColumn, RobotIDColumn, DisplayNameColumn, CreatedAtColumn}
+		defaultColumns    = postgres.ColumnList{CreatedAtColumn}
+	)
+
+	return robotFriendRequestsTable{
+		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
+
+		//Columns
+		ID:          IDColumn,
+		RequesterID: RequesterIDColumn,
+		GameID:      GameIDColumn,
+		Seat:        SeatColumn,
+		RobotID:     RobotIDColumn,
+		DisplayName: DisplayNameColumn,
+		CreatedAt:   CreatedAtColumn,
+
+		AllColumns:     allColumns,
+		MutableColumns: mutableColumns,
+		DefaultColumns: defaultColumns,
+	}
+}

backend/internal/postgres/jet/backend/table/table_use_schema.go

@@ -10,6 +10,7 @@ package table
 // UseSchema sets a new schema name for all generated table SQL builder types. It is recommended to invoke
 // this method only once at the beginning of the program.
 func UseSchema(schema string) {
+	AccountBestMove = AccountBestMove.FromSchema(schema)
 	AccountRoles = AccountRoles.FromSchema(schema)
 	AccountStats = AccountStats.FromSchema(schema)
 	AccountSuspensions = AccountSuspensions.FromSchema(schema)
@@ -35,6 +36,8 @@ func UseSchema(schema string) {
 	Games = Games.FromSchema(schema)
 	Identities = Identities.FromSchema(schema)
 	RetainedIdentities = RetainedIdentities.FromSchema(schema)
+	RobotBlocks = RobotBlocks.FromSchema(schema)
+	RobotFriendRequests = RobotFriendRequests.FromSchema(schema)
 	Sessions = Sessions.FromSchema(schema)
 	SuspensionReasons = SuspensionReasons.FromSchema(schema)
 }

backend/internal/postgres/jet/payments/model/balances.go

@@ -0,0 +1,20 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package model
+
+import (
+	"github.com/google/uuid"
+	"time"
+)
+
+type Balances struct {
+	AccountID uuid.UUID `sql:"primary_key"`
+	Source    string    `sql:"primary_key"`
+	Chips     int32
+	UpdatedAt time.Time
+}

backend/internal/postgres/jet/payments/model/benefits.go

@@ -0,0 +1,22 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package model
+
+import (
+	"github.com/google/uuid"
+	"time"
+)
+
+type Benefits struct {
+	AccountID    uuid.UUID `sql:"primary_key"`
+	Origin       string    `sql:"primary_key"`
+	AdsPaidUntil *time.Time
+	AdsForever   bool
+	Hints        int32
+	UpdatedAt    time.Time
+}

backend/internal/postgres/jet/payments/model/catalog_atom.go

@@ -0,0 +1,12 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package model
+
+type CatalogAtom struct {
+	AtomType string `sql:"primary_key"`
+}

backend/internal/postgres/jet/payments/model/config.go

@@ -0,0 +1,17 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package model
+
+type Config struct {
+	OnlyRow               bool `sql:"primary_key"`
+	RewardedPayoutChips   int32
+	CooldownGlobalSeconds int32
+	CooldownVsAiSeconds   int32
+	CooldownHintSeconds   int32
+	OrderTTLSeconds       int32
+}

backend/internal/postgres/jet/payments/model/ledger.go

@@ -0,0 +1,28 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package model
+
+import (
+	"github.com/google/uuid"
+	"time"
+)
+
+type Ledger struct {
+	LedgerID          uuid.UUID `sql:"primary_key"`
+	AccountID         uuid.UUID
+	Kind              string
+	Source            *string
+	Origin            *string
+	ChipsDelta        int32
+	ProductID         *uuid.UUID
+	OrderID           *uuid.UUID
+	Provider          *string
+	ProviderPaymentID *string
+	Snapshot          *string
+	CreatedAt         time.Time
+}

backend/internal/postgres/jet/payments/model/orders.go

@@ -0,0 +1,28 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package model
+
+import (
+	"github.com/google/uuid"
+	"time"
+)
+
+type Orders struct {
+	OrderID           uuid.UUID `sql:"primary_key"`
+	AccountID         uuid.UUID
+	Platform          string
+	ProductID         uuid.UUID
+	ExpectedAmount    int64
+	Currency          string
+	Origin            string
+	Status            string
+	Provider          *string
+	ProviderPaymentID *string
+	CreatedAt         time.Time
+	UpdatedAt         time.Time
+}

backend/internal/postgres/jet/payments/model/payment_events.go

@@ -0,0 +1,23 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package model
+
+import (
+	"github.com/google/uuid"
+	"time"
+)
+
+type PaymentEvents struct {
+	EventID      uuid.UUID `sql:"primary_key"`
+	AccountID    uuid.UUID
+	OrderID      *uuid.UUID
+	Type         string
+	Payload      *string
+	CreatedAt    time.Time
+	DispatchedAt *time.Time
+}

backend/internal/postgres/jet/payments/model/product.go

@@ -0,0 +1,21 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package model
+
+import (
+	"github.com/google/uuid"
+	"time"
+)
+
+type Product struct {
+	ProductID uuid.UUID `sql:"primary_key"`
+	Title     string
+	Active    bool
+	CreatedAt time.Time
+	UpdatedAt time.Time
+}

backend/internal/postgres/jet/payments/model/product_item.go

@@ -0,0 +1,18 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package model
+
+import (
+	"github.com/google/uuid"
+)
+
+type ProductItem struct {
+	ProductID uuid.UUID `sql:"primary_key"`
+	AtomType  string    `sql:"primary_key"`
+	Quantity  int32
+}

backend/internal/postgres/jet/payments/model/product_price.go

@@ -0,0 +1,19 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package model
+
+import (
+	"github.com/google/uuid"
+)
+
+type ProductPrice struct {
+	ProductID uuid.UUID
+	Method    *string
+	Currency  string
+	Amount    int64
+}

backend/internal/postgres/jet/payments/table/balances.go

@@ -0,0 +1,87 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package table
+
+import (
+	"github.com/go-jet/jet/v2/postgres"
+)
+
+var Balances = newBalancesTable("payments", "balances", "")
+
+type balancesTable struct {
+	postgres.Table
+
+	// Columns
+	AccountID postgres.ColumnString
+	Source    postgres.ColumnString
+	Chips     postgres.ColumnInteger
+	UpdatedAt postgres.ColumnTimestampz
+
+	AllColumns     postgres.ColumnList
+	MutableColumns postgres.ColumnList
+	DefaultColumns postgres.ColumnList
+}
+
+type BalancesTable struct {
+	balancesTable
+
+	EXCLUDED balancesTable
+}
+
+// AS creates new BalancesTable with assigned alias
+func (a BalancesTable) AS(alias string) *BalancesTable {
+	return newBalancesTable(a.SchemaName(), a.TableName(), alias)
+}
+
+// Schema creates new BalancesTable with assigned schema name
+func (a BalancesTable) FromSchema(schemaName string) *BalancesTable {
+	return newBalancesTable(schemaName, a.TableName(), a.Alias())
+}
+
+// WithPrefix creates new BalancesTable with assigned table prefix
+func (a BalancesTable) WithPrefix(prefix string) *BalancesTable {
+	return newBalancesTable(a.SchemaName(), prefix+a.TableName(), a.TableName())
+}
+
+// WithSuffix creates new BalancesTable with assigned table suffix
+func (a BalancesTable) WithSuffix(suffix string) *BalancesTable {
+	return newBalancesTable(a.SchemaName(), a.TableName()+suffix, a.TableName())
+}
+
+func newBalancesTable(schemaName, tableName, alias string) *BalancesTable {
+	return &BalancesTable{
+		balancesTable: newBalancesTableImpl(schemaName, tableName, alias),
+		EXCLUDED:      newBalancesTableImpl("", "excluded", ""),
+	}
+}
+
+func newBalancesTableImpl(schemaName, tableName, alias string) balancesTable {
+	var (
+		AccountIDColumn = postgres.StringColumn("account_id")
+		SourceColumn    = postgres.StringColumn("source")
+		ChipsColumn     = postgres.IntegerColumn("chips")
+		UpdatedAtColumn = postgres.TimestampzColumn("updated_at")
+		allColumns      = postgres.ColumnList{AccountIDColumn, SourceColumn, ChipsColumn, UpdatedAtColumn}
+		mutableColumns  = postgres.ColumnList{ChipsColumn, UpdatedAtColumn}
+		defaultColumns  = postgres.ColumnList{ChipsColumn, UpdatedAtColumn}
+	)
+
+	return balancesTable{
+		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
+
+		//Columns
+		AccountID: AccountIDColumn,
+		Source:    SourceColumn,
+		Chips:     ChipsColumn,
+		UpdatedAt: UpdatedAtColumn,
+
+		AllColumns:     allColumns,
+		MutableColumns: mutableColumns,
+		DefaultColumns: defaultColumns,
+	}
+}

backend/internal/postgres/jet/payments/table/benefits.go

@@ -0,0 +1,93 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package table
+
+import (
+	"github.com/go-jet/jet/v2/postgres"
+)
+
+var Benefits = newBenefitsTable("payments", "benefits", "")
+
+type benefitsTable struct {
+	postgres.Table
+
+	// Columns
+	AccountID    postgres.ColumnString
+	Origin       postgres.ColumnString
+	AdsPaidUntil postgres.ColumnTimestampz
+	AdsForever   postgres.ColumnBool
+	Hints        postgres.ColumnInteger
+	UpdatedAt    postgres.ColumnTimestampz
+
+	AllColumns     postgres.ColumnList
+	MutableColumns postgres.ColumnList
+	DefaultColumns postgres.ColumnList
+}
+
+type BenefitsTable struct {
+	benefitsTable
+
+	EXCLUDED benefitsTable
+}
+
+// AS creates new BenefitsTable with assigned alias
+func (a BenefitsTable) AS(alias string) *BenefitsTable {
+	return newBenefitsTable(a.SchemaName(), a.TableName(), alias)
+}
+
+// Schema creates new BenefitsTable with assigned schema name
+func (a BenefitsTable) FromSchema(schemaName string) *BenefitsTable {
+	return newBenefitsTable(schemaName, a.TableName(), a.Alias())
+}
+
+// WithPrefix creates new BenefitsTable with assigned table prefix
+func (a BenefitsTable) WithPrefix(prefix string) *BenefitsTable {
+	return newBenefitsTable(a.SchemaName(), prefix+a.TableName(), a.TableName())
+}
+
+// WithSuffix creates new BenefitsTable with assigned table suffix
+func (a BenefitsTable) WithSuffix(suffix string) *BenefitsTable {
+	return newBenefitsTable(a.SchemaName(), a.TableName()+suffix, a.TableName())
+}
+
+func newBenefitsTable(schemaName, tableName, alias string) *BenefitsTable {
+	return &BenefitsTable{
+		benefitsTable: newBenefitsTableImpl(schemaName, tableName, alias),
+		EXCLUDED:      newBenefitsTableImpl("", "excluded", ""),
+	}
+}
+
+func newBenefitsTableImpl(schemaName, tableName, alias string) benefitsTable {
+	var (
+		AccountIDColumn    = postgres.StringColumn("account_id")
+		OriginColumn       = postgres.StringColumn("origin")
+		AdsPaidUntilColumn = postgres.TimestampzColumn("ads_paid_until")
+		AdsForeverColumn   = postgres.BoolColumn("ads_forever")
+		HintsColumn        = postgres.IntegerColumn("hints")
+		UpdatedAtColumn    = postgres.TimestampzColumn("updated_at")
+		allColumns         = postgres.ColumnList{AccountIDColumn, OriginColumn, AdsPaidUntilColumn, AdsForeverColumn, HintsColumn, UpdatedAtColumn}
+		mutableColumns     = postgres.ColumnList{AdsPaidUntilColumn, AdsForeverColumn, HintsColumn, UpdatedAtColumn}
+		defaultColumns     = postgres.ColumnList{AdsForeverColumn, HintsColumn, UpdatedAtColumn}
+	)
+
+	return benefitsTable{
+		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
+
+		//Columns
+		AccountID:    AccountIDColumn,
+		Origin:       OriginColumn,
+		AdsPaidUntil: AdsPaidUntilColumn,
+		AdsForever:   AdsForeverColumn,
+		Hints:        HintsColumn,
+		UpdatedAt:    UpdatedAtColumn,
+
+		AllColumns:     allColumns,
+		MutableColumns: mutableColumns,
+		DefaultColumns: defaultColumns,
+	}
+}

backend/internal/postgres/jet/payments/table/catalog_atom.go

@@ -0,0 +1,78 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package table
+
+import (
+	"github.com/go-jet/jet/v2/postgres"
+)
+
+var CatalogAtom = newCatalogAtomTable("payments", "catalog_atom", "")
+
+type catalogAtomTable struct {
+	postgres.Table
+
+	// Columns
+	AtomType postgres.ColumnString
+
+	AllColumns     postgres.ColumnList
+	MutableColumns postgres.ColumnList
+	DefaultColumns postgres.ColumnList
+}
+
+type CatalogAtomTable struct {
+	catalogAtomTable
+
+	EXCLUDED catalogAtomTable
+}
+
+// AS creates new CatalogAtomTable with assigned alias
+func (a CatalogAtomTable) AS(alias string) *CatalogAtomTable {
+	return newCatalogAtomTable(a.SchemaName(), a.TableName(), alias)
+}
+
+// Schema creates new CatalogAtomTable with assigned schema name
+func (a CatalogAtomTable) FromSchema(schemaName string) *CatalogAtomTable {
+	return newCatalogAtomTable(schemaName, a.TableName(), a.Alias())
+}
+
+// WithPrefix creates new CatalogAtomTable with assigned table prefix
+func (a CatalogAtomTable) WithPrefix(prefix string) *CatalogAtomTable {
+	return newCatalogAtomTable(a.SchemaName(), prefix+a.TableName(), a.TableName())
+}
+
+// WithSuffix creates new CatalogAtomTable with assigned table suffix
+func (a CatalogAtomTable) WithSuffix(suffix string) *CatalogAtomTable {
+	return newCatalogAtomTable(a.SchemaName(), a.TableName()+suffix, a.TableName())
+}
+
+func newCatalogAtomTable(schemaName, tableName, alias string) *CatalogAtomTable {
+	return &CatalogAtomTable{
+		catalogAtomTable: newCatalogAtomTableImpl(schemaName, tableName, alias),
+		EXCLUDED:         newCatalogAtomTableImpl("", "excluded", ""),
+	}
+}
+
+func newCatalogAtomTableImpl(schemaName, tableName, alias string) catalogAtomTable {
+	var (
+		AtomTypeColumn = postgres.StringColumn("atom_type")
+		allColumns     = postgres.ColumnList{AtomTypeColumn}
+		mutableColumns = postgres.ColumnList{}
+		defaultColumns = postgres.ColumnList{}
+	)
+
+	return catalogAtomTable{
+		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
+
+		//Columns
+		AtomType: AtomTypeColumn,
+
+		AllColumns:     allColumns,
+		MutableColumns: mutableColumns,
+		DefaultColumns: defaultColumns,
+	}
+}

backend/internal/postgres/jet/payments/table/config.go

@@ -0,0 +1,93 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package table
+
+import (
+	"github.com/go-jet/jet/v2/postgres"
+)
+
+var Config = newConfigTable("payments", "config", "")
+
+type configTable struct {
+	postgres.Table
+
+	// Columns
+	OnlyRow               postgres.ColumnBool
+	RewardedPayoutChips   postgres.ColumnInteger
+	CooldownGlobalSeconds postgres.ColumnInteger
+	CooldownVsAiSeconds   postgres.ColumnInteger
+	CooldownHintSeconds   postgres.ColumnInteger
+	OrderTTLSeconds       postgres.ColumnInteger
+
+	AllColumns     postgres.ColumnList
+	MutableColumns postgres.ColumnList
+	DefaultColumns postgres.ColumnList
+}
+
+type ConfigTable struct {
+	configTable
+
+	EXCLUDED configTable
+}
+
+// AS creates new ConfigTable with assigned alias
+func (a ConfigTable) AS(alias string) *ConfigTable {
+	return newConfigTable(a.SchemaName(), a.TableName(), alias)
+}
+
+// Schema creates new ConfigTable with assigned schema name
+func (a ConfigTable) FromSchema(schemaName string) *ConfigTable {
+	return newConfigTable(schemaName, a.TableName(), a.Alias())
+}
+
+// WithPrefix creates new ConfigTable with assigned table prefix
+func (a ConfigTable) WithPrefix(prefix string) *ConfigTable {
+	return newConfigTable(a.SchemaName(), prefix+a.TableName(), a.TableName())
+}
+
+// WithSuffix creates new ConfigTable with assigned table suffix
+func (a ConfigTable) WithSuffix(suffix string) *ConfigTable {
+	return newConfigTable(a.SchemaName(), a.TableName()+suffix, a.TableName())
+}
+
+func newConfigTable(schemaName, tableName, alias string) *ConfigTable {
+	return &ConfigTable{
+		configTable: newConfigTableImpl(schemaName, tableName, alias),
+		EXCLUDED:    newConfigTableImpl("", "excluded", ""),
+	}
+}
+
+func newConfigTableImpl(schemaName, tableName, alias string) configTable {
+	var (
+		OnlyRowColumn               = postgres.BoolColumn("only_row")
+		RewardedPayoutChipsColumn   = postgres.IntegerColumn("rewarded_payout_chips")
+		CooldownGlobalSecondsColumn = postgres.IntegerColumn("cooldown_global_seconds")
+		CooldownVsAiSecondsColumn   = postgres.IntegerColumn("cooldown_vs_ai_seconds")
+		CooldownHintSecondsColumn   = postgres.IntegerColumn("cooldown_hint_seconds")
+		OrderTTLSecondsColumn       = postgres.IntegerColumn("order_ttl_seconds")
+		allColumns                  = postgres.ColumnList{OnlyRowColumn, RewardedPayoutChipsColumn, CooldownGlobalSecondsColumn, CooldownVsAiSecondsColumn, CooldownHintSecondsColumn, OrderTTLSecondsColumn}
+		mutableColumns              = postgres.ColumnList{RewardedPayoutChipsColumn, CooldownGlobalSecondsColumn, CooldownVsAiSecondsColumn, CooldownHintSecondsColumn, OrderTTLSecondsColumn}
+		defaultColumns              = postgres.ColumnList{OnlyRowColumn, RewardedPayoutChipsColumn, CooldownGlobalSecondsColumn, CooldownVsAiSecondsColumn, CooldownHintSecondsColumn, OrderTTLSecondsColumn}
+	)
+
+	return configTable{
+		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
+
+		//Columns
+		OnlyRow:               OnlyRowColumn,
+		RewardedPayoutChips:   RewardedPayoutChipsColumn,
+		CooldownGlobalSeconds: CooldownGlobalSecondsColumn,
+		CooldownVsAiSeconds:   CooldownVsAiSecondsColumn,
+		CooldownHintSeconds:   CooldownHintSecondsColumn,
+		OrderTTLSeconds:       OrderTTLSecondsColumn,
+
+		AllColumns:     allColumns,
+		MutableColumns: mutableColumns,
+		DefaultColumns: defaultColumns,
+	}
+}

backend/internal/postgres/jet/payments/table/ledger.go

@@ -0,0 +1,111 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package table
+
+import (
+	"github.com/go-jet/jet/v2/postgres"
+)
+
+var Ledger = newLedgerTable("payments", "ledger", "")
+
+type ledgerTable struct {
+	postgres.Table
+
+	// Columns
+	LedgerID          postgres.ColumnString
+	AccountID         postgres.ColumnString
+	Kind              postgres.ColumnString
+	Source            postgres.ColumnString
+	Origin            postgres.ColumnString
+	ChipsDelta        postgres.ColumnInteger
+	ProductID         postgres.ColumnString
+	OrderID           postgres.ColumnString
+	Provider          postgres.ColumnString
+	ProviderPaymentID postgres.ColumnString
+	Snapshot          postgres.ColumnString
+	CreatedAt         postgres.ColumnTimestampz
+
+	AllColumns     postgres.ColumnList
+	MutableColumns postgres.ColumnList
+	DefaultColumns postgres.ColumnList
+}
+
+type LedgerTable struct {
+	ledgerTable
+
+	EXCLUDED ledgerTable
+}
+
+// AS creates new LedgerTable with assigned alias
+func (a LedgerTable) AS(alias string) *LedgerTable {
+	return newLedgerTable(a.SchemaName(), a.TableName(), alias)
+}
+
+// Schema creates new LedgerTable with assigned schema name
+func (a LedgerTable) FromSchema(schemaName string) *LedgerTable {
+	return newLedgerTable(schemaName, a.TableName(), a.Alias())
+}
+
+// WithPrefix creates new LedgerTable with assigned table prefix
+func (a LedgerTable) WithPrefix(prefix string) *LedgerTable {
+	return newLedgerTable(a.SchemaName(), prefix+a.TableName(), a.TableName())
+}
+
+// WithSuffix creates new LedgerTable with assigned table suffix
+func (a LedgerTable) WithSuffix(suffix string) *LedgerTable {
+	return newLedgerTable(a.SchemaName(), a.TableName()+suffix, a.TableName())
+}
+
+func newLedgerTable(schemaName, tableName, alias string) *LedgerTable {
+	return &LedgerTable{
+		ledgerTable: newLedgerTableImpl(schemaName, tableName, alias),
+		EXCLUDED:    newLedgerTableImpl("", "excluded", ""),
+	}
+}
+
+func newLedgerTableImpl(schemaName, tableName, alias string) ledgerTable {
+	var (
+		LedgerIDColumn          = postgres.StringColumn("ledger_id")
+		AccountIDColumn         = postgres.StringColumn("account_id")
+		KindColumn              = postgres.StringColumn("kind")
+		SourceColumn            = postgres.StringColumn("source")
+		OriginColumn            = postgres.StringColumn("origin")
+		ChipsDeltaColumn        = postgres.IntegerColumn("chips_delta")
+		ProductIDColumn         = postgres.StringColumn("product_id")
+		OrderIDColumn           = postgres.StringColumn("order_id")
+		ProviderColumn          = postgres.StringColumn("provider")
+		ProviderPaymentIDColumn = postgres.StringColumn("provider_payment_id")
+		SnapshotColumn          = postgres.StringColumn("snapshot")
+		CreatedAtColumn         = postgres.TimestampzColumn("created_at")
+		allColumns              = postgres.ColumnList{LedgerIDColumn, AccountIDColumn, KindColumn, SourceColumn, OriginColumn, ChipsDeltaColumn, ProductIDColumn, OrderIDColumn, ProviderColumn, ProviderPaymentIDColumn, SnapshotColumn, CreatedAtColumn}
+		mutableColumns          = postgres.ColumnList{AccountIDColumn, KindColumn, SourceColumn, OriginColumn, ChipsDeltaColumn, ProductIDColumn, OrderIDColumn, ProviderColumn, ProviderPaymentIDColumn, SnapshotColumn, CreatedAtColumn}
+		defaultColumns          = postgres.ColumnList{ChipsDeltaColumn, CreatedAtColumn}
+	)
+
+	return ledgerTable{
+		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
+
+		//Columns
+		LedgerID:          LedgerIDColumn,
+		AccountID:         AccountIDColumn,
+		Kind:              KindColumn,
+		Source:            SourceColumn,
+		Origin:            OriginColumn,
+		ChipsDelta:        ChipsDeltaColumn,
+		ProductID:         ProductIDColumn,
+		OrderID:           OrderIDColumn,
+		Provider:          ProviderColumn,
+		ProviderPaymentID: ProviderPaymentIDColumn,
+		Snapshot:          SnapshotColumn,
+		CreatedAt:         CreatedAtColumn,
+
+		AllColumns:     allColumns,
+		MutableColumns: mutableColumns,
+		DefaultColumns: defaultColumns,
+	}
+}

backend/internal/postgres/jet/payments/table/orders.go

@@ -0,0 +1,111 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package table
+
+import (
+	"github.com/go-jet/jet/v2/postgres"
+)
+
+var Orders = newOrdersTable("payments", "orders", "")
+
+type ordersTable struct {
+	postgres.Table
+
+	// Columns
+	OrderID           postgres.ColumnString
+	AccountID         postgres.ColumnString
+	Platform          postgres.ColumnString
+	ProductID         postgres.ColumnString
+	ExpectedAmount    postgres.ColumnInteger
+	Currency          postgres.ColumnString
+	Origin            postgres.ColumnString
+	Status            postgres.ColumnString
+	Provider          postgres.ColumnString
+	ProviderPaymentID postgres.ColumnString
+	CreatedAt         postgres.ColumnTimestampz
+	UpdatedAt         postgres.ColumnTimestampz
+
+	AllColumns     postgres.ColumnList
+	MutableColumns postgres.ColumnList
+	DefaultColumns postgres.ColumnList
+}
+
+type OrdersTable struct {
+	ordersTable
+
+	EXCLUDED ordersTable
+}
+
+// AS creates new OrdersTable with assigned alias
+func (a OrdersTable) AS(alias string) *OrdersTable {
+	return newOrdersTable(a.SchemaName(), a.TableName(), alias)
+}
+
+// Schema creates new OrdersTable with assigned schema name
+func (a OrdersTable) FromSchema(schemaName string) *OrdersTable {
+	return newOrdersTable(schemaName, a.TableName(), a.Alias())
+}
+
+// WithPrefix creates new OrdersTable with assigned table prefix
+func (a OrdersTable) WithPrefix(prefix string) *OrdersTable {
+	return newOrdersTable(a.SchemaName(), prefix+a.TableName(), a.TableName())
+}
+
+// WithSuffix creates new OrdersTable with assigned table suffix
+func (a OrdersTable) WithSuffix(suffix string) *OrdersTable {
+	return newOrdersTable(a.SchemaName(), a.TableName()+suffix, a.TableName())
+}
+
+func newOrdersTable(schemaName, tableName, alias string) *OrdersTable {
+	return &OrdersTable{
+		ordersTable: newOrdersTableImpl(schemaName, tableName, alias),
+		EXCLUDED:    newOrdersTableImpl("", "excluded", ""),
+	}
+}
+
+func newOrdersTableImpl(schemaName, tableName, alias string) ordersTable {
+	var (
+		OrderIDColumn           = postgres.StringColumn("order_id")
+		AccountIDColumn         = postgres.StringColumn("account_id")
+		PlatformColumn          = postgres.StringColumn("platform")
+		ProductIDColumn         = postgres.StringColumn("product_id")
+		ExpectedAmountColumn    = postgres.IntegerColumn("expected_amount")
+		CurrencyColumn          = postgres.StringColumn("currency")
+		OriginColumn            = postgres.StringColumn("origin")
+		StatusColumn            = postgres.StringColumn("status")
+		ProviderColumn          = postgres.StringColumn("provider")
+		ProviderPaymentIDColumn = postgres.StringColumn("provider_payment_id")
+		CreatedAtColumn         = postgres.TimestampzColumn("created_at")
+		UpdatedAtColumn         = postgres.TimestampzColumn("updated_at")
+		allColumns              = postgres.ColumnList{OrderIDColumn, AccountIDColumn, PlatformColumn, ProductIDColumn, ExpectedAmountColumn, CurrencyColumn, OriginColumn, StatusColumn, ProviderColumn, ProviderPaymentIDColumn, CreatedAtColumn, UpdatedAtColumn}
+		mutableColumns          = postgres.ColumnList{AccountIDColumn, PlatformColumn, ProductIDColumn, ExpectedAmountColumn, CurrencyColumn, OriginColumn, StatusColumn, ProviderColumn, ProviderPaymentIDColumn, CreatedAtColumn, UpdatedAtColumn}
+		defaultColumns          = postgres.ColumnList{StatusColumn, CreatedAtColumn, UpdatedAtColumn}
+	)
+
+	return ordersTable{
+		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
+
+		//Columns
+		OrderID:           OrderIDColumn,
+		AccountID:         AccountIDColumn,
+		Platform:          PlatformColumn,
+		ProductID:         ProductIDColumn,
+		ExpectedAmount:    ExpectedAmountColumn,
+		Currency:          CurrencyColumn,
+		Origin:            OriginColumn,
+		Status:            StatusColumn,
+		Provider:          ProviderColumn,
+		ProviderPaymentID: ProviderPaymentIDColumn,
+		CreatedAt:         CreatedAtColumn,
+		UpdatedAt:         UpdatedAtColumn,
+
+		AllColumns:     allColumns,
+		MutableColumns: mutableColumns,
+		DefaultColumns: defaultColumns,
+	}
+}

backend/internal/postgres/jet/payments/table/payment_events.go

@@ -0,0 +1,96 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package table
+
+import (
+	"github.com/go-jet/jet/v2/postgres"
+)
+
+var PaymentEvents = newPaymentEventsTable("payments", "payment_events", "")
+
+type paymentEventsTable struct {
+	postgres.Table
+
+	// Columns
+	EventID      postgres.ColumnString
+	AccountID    postgres.ColumnString
+	OrderID      postgres.ColumnString
+	Type         postgres.ColumnString
+	Payload      postgres.ColumnString
+	CreatedAt    postgres.ColumnTimestampz
+	DispatchedAt postgres.ColumnTimestampz
+
+	AllColumns     postgres.ColumnList
+	MutableColumns postgres.ColumnList
+	DefaultColumns postgres.ColumnList
+}
+
+type PaymentEventsTable struct {
+	paymentEventsTable
+
+	EXCLUDED paymentEventsTable
+}
+
+// AS creates new PaymentEventsTable with assigned alias
+func (a PaymentEventsTable) AS(alias string) *PaymentEventsTable {
+	return newPaymentEventsTable(a.SchemaName(), a.TableName(), alias)
+}
+
+// Schema creates new PaymentEventsTable with assigned schema name
+func (a PaymentEventsTable) FromSchema(schemaName string) *PaymentEventsTable {
+	return newPaymentEventsTable(schemaName, a.TableName(), a.Alias())
+}
+
+// WithPrefix creates new PaymentEventsTable with assigned table prefix
+func (a PaymentEventsTable) WithPrefix(prefix string) *PaymentEventsTable {
+	return newPaymentEventsTable(a.SchemaName(), prefix+a.TableName(), a.TableName())
+}
+
+// WithSuffix creates new PaymentEventsTable with assigned table suffix
+func (a PaymentEventsTable) WithSuffix(suffix string) *PaymentEventsTable {
+	return newPaymentEventsTable(a.SchemaName(), a.TableName()+suffix, a.TableName())
+}
+
+func newPaymentEventsTable(schemaName, tableName, alias string) *PaymentEventsTable {
+	return &PaymentEventsTable{
+		paymentEventsTable: newPaymentEventsTableImpl(schemaName, tableName, alias),
+		EXCLUDED:           newPaymentEventsTableImpl("", "excluded", ""),
+	}
+}
+
+func newPaymentEventsTableImpl(schemaName, tableName, alias string) paymentEventsTable {
+	var (
+		EventIDColumn      = postgres.StringColumn("event_id")
+		AccountIDColumn    = postgres.StringColumn("account_id")
+		OrderIDColumn      = postgres.StringColumn("order_id")
+		TypeColumn         = postgres.StringColumn("type")
+		PayloadColumn      = postgres.StringColumn("payload")
+		CreatedAtColumn    = postgres.TimestampzColumn("created_at")
+		DispatchedAtColumn = postgres.TimestampzColumn("dispatched_at")
+		allColumns         = postgres.ColumnList{EventIDColumn, AccountIDColumn, OrderIDColumn, TypeColumn, PayloadColumn, CreatedAtColumn, DispatchedAtColumn}
+		mutableColumns     = postgres.ColumnList{AccountIDColumn, OrderIDColumn, TypeColumn, PayloadColumn, CreatedAtColumn, DispatchedAtColumn}
+		defaultColumns     = postgres.ColumnList{CreatedAtColumn}
+	)
+
+	return paymentEventsTable{
+		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
+
+		//Columns
+		EventID:      EventIDColumn,
+		AccountID:    AccountIDColumn,
+		OrderID:      OrderIDColumn,
+		Type:         TypeColumn,
+		Payload:      PayloadColumn,
+		CreatedAt:    CreatedAtColumn,
+		DispatchedAt: DispatchedAtColumn,
+
+		AllColumns:     allColumns,
+		MutableColumns: mutableColumns,
+		DefaultColumns: defaultColumns,
+	}
+}

backend/internal/postgres/jet/payments/table/product.go

@@ -0,0 +1,90 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package table
+
+import (
+	"github.com/go-jet/jet/v2/postgres"
+)
+
+var Product = newProductTable("payments", "product", "")
+
+type productTable struct {
+	postgres.Table
+
+	// Columns
+	ProductID postgres.ColumnString
+	Title     postgres.ColumnString
+	Active    postgres.ColumnBool
+	CreatedAt postgres.ColumnTimestampz
+	UpdatedAt postgres.ColumnTimestampz
+
+	AllColumns     postgres.ColumnList
+	MutableColumns postgres.ColumnList
+	DefaultColumns postgres.ColumnList
+}
+
+type ProductTable struct {
+	productTable
+
+	EXCLUDED productTable
+}
+
+// AS creates new ProductTable with assigned alias
+func (a ProductTable) AS(alias string) *ProductTable {
+	return newProductTable(a.SchemaName(), a.TableName(), alias)
+}
+
+// Schema creates new ProductTable with assigned schema name
+func (a ProductTable) FromSchema(schemaName string) *ProductTable {
+	return newProductTable(schemaName, a.TableName(), a.Alias())
+}
+
+// WithPrefix creates new ProductTable with assigned table prefix
+func (a ProductTable) WithPrefix(prefix string) *ProductTable {
+	return newProductTable(a.SchemaName(), prefix+a.TableName(), a.TableName())
+}
+
+// WithSuffix creates new ProductTable with assigned table suffix
+func (a ProductTable) WithSuffix(suffix string) *ProductTable {
+	return newProductTable(a.SchemaName(), a.TableName()+suffix, a.TableName())
+}
+
+func newProductTable(schemaName, tableName, alias string) *ProductTable {
+	return &ProductTable{
+		productTable: newProductTableImpl(schemaName, tableName, alias),
+		EXCLUDED:     newProductTableImpl("", "excluded", ""),
+	}
+}
+
+func newProductTableImpl(schemaName, tableName, alias string) productTable {
+	var (
+		ProductIDColumn = postgres.StringColumn("product_id")
+		TitleColumn     = postgres.StringColumn("title")
+		ActiveColumn    = postgres.BoolColumn("active")
+		CreatedAtColumn = postgres.TimestampzColumn("created_at")
+		UpdatedAtColumn = postgres.TimestampzColumn("updated_at")
+		allColumns      = postgres.ColumnList{ProductIDColumn, TitleColumn, ActiveColumn, CreatedAtColumn, UpdatedAtColumn}
+		mutableColumns  = postgres.ColumnList{TitleColumn, ActiveColumn, CreatedAtColumn, UpdatedAtColumn}
+		defaultColumns  = postgres.ColumnList{TitleColumn, ActiveColumn, CreatedAtColumn, UpdatedAtColumn}
+	)
+
+	return productTable{
+		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
+
+		//Columns
+		ProductID: ProductIDColumn,
+		Title:     TitleColumn,
+		Active:    ActiveColumn,
+		CreatedAt: CreatedAtColumn,
+		UpdatedAt: UpdatedAtColumn,
+
+		AllColumns:     allColumns,
+		MutableColumns: mutableColumns,
+		DefaultColumns: defaultColumns,
+	}
+}

backend/internal/postgres/jet/payments/table/product_item.go

@@ -0,0 +1,84 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package table
+
+import (
+	"github.com/go-jet/jet/v2/postgres"
+)
+
+var ProductItem = newProductItemTable("payments", "product_item", "")
+
+type productItemTable struct {
+	postgres.Table
+
+	// Columns
+	ProductID postgres.ColumnString
+	AtomType  postgres.ColumnString
+	Quantity  postgres.ColumnInteger
+
+	AllColumns     postgres.ColumnList
+	MutableColumns postgres.ColumnList
+	DefaultColumns postgres.ColumnList
+}
+
+type ProductItemTable struct {
+	productItemTable
+
+	EXCLUDED productItemTable
+}
+
+// AS creates new ProductItemTable with assigned alias
+func (a ProductItemTable) AS(alias string) *ProductItemTable {
+	return newProductItemTable(a.SchemaName(), a.TableName(), alias)
+}
+
+// Schema creates new ProductItemTable with assigned schema name
+func (a ProductItemTable) FromSchema(schemaName string) *ProductItemTable {
+	return newProductItemTable(schemaName, a.TableName(), a.Alias())
+}
+
+// WithPrefix creates new ProductItemTable with assigned table prefix
+func (a ProductItemTable) WithPrefix(prefix string) *ProductItemTable {
+	return newProductItemTable(a.SchemaName(), prefix+a.TableName(), a.TableName())
+}
+
+// WithSuffix creates new ProductItemTable with assigned table suffix
+func (a ProductItemTable) WithSuffix(suffix string) *ProductItemTable {
+	return newProductItemTable(a.SchemaName(), a.TableName()+suffix, a.TableName())
+}
+
+func newProductItemTable(schemaName, tableName, alias string) *ProductItemTable {
+	return &ProductItemTable{
+		productItemTable: newProductItemTableImpl(schemaName, tableName, alias),
+		EXCLUDED:         newProductItemTableImpl("", "excluded", ""),
+	}
+}
+
+func newProductItemTableImpl(schemaName, tableName, alias string) productItemTable {
+	var (
+		ProductIDColumn = postgres.StringColumn("product_id")
+		AtomTypeColumn  = postgres.StringColumn("atom_type")
+		QuantityColumn  = postgres.IntegerColumn("quantity")
+		allColumns      = postgres.ColumnList{ProductIDColumn, AtomTypeColumn, QuantityColumn}
+		mutableColumns  = postgres.ColumnList{QuantityColumn}
+		defaultColumns  = postgres.ColumnList{}
+	)
+
+	return productItemTable{
+		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
+
+		//Columns
+		ProductID: ProductIDColumn,
+		AtomType:  AtomTypeColumn,
+		Quantity:  QuantityColumn,
+
+		AllColumns:     allColumns,
+		MutableColumns: mutableColumns,
+		DefaultColumns: defaultColumns,
+	}
+}

backend/internal/postgres/jet/payments/table/product_price.go

@@ -0,0 +1,87 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package table
+
+import (
+	"github.com/go-jet/jet/v2/postgres"
+)
+
+var ProductPrice = newProductPriceTable("payments", "product_price", "")
+
+type productPriceTable struct {
+	postgres.Table
+
+	// Columns
+	ProductID postgres.ColumnString
+	Method    postgres.ColumnString
+	Currency  postgres.ColumnString
+	Amount    postgres.ColumnInteger
+
+	AllColumns     postgres.ColumnList
+	MutableColumns postgres.ColumnList
+	DefaultColumns postgres.ColumnList
+}
+
+type ProductPriceTable struct {
+	productPriceTable
+
+	EXCLUDED productPriceTable
+}
+
+// AS creates new ProductPriceTable with assigned alias
+func (a ProductPriceTable) AS(alias string) *ProductPriceTable {
+	return newProductPriceTable(a.SchemaName(), a.TableName(), alias)
+}
+
+// Schema creates new ProductPriceTable with assigned schema name
+func (a ProductPriceTable) FromSchema(schemaName string) *ProductPriceTable {
+	return newProductPriceTable(schemaName, a.TableName(), a.Alias())
+}
+
+// WithPrefix creates new ProductPriceTable with assigned table prefix
+func (a ProductPriceTable) WithPrefix(prefix string) *ProductPriceTable {
+	return newProductPriceTable(a.SchemaName(), prefix+a.TableName(), a.TableName())
+}
+
+// WithSuffix creates new ProductPriceTable with assigned table suffix
+func (a ProductPriceTable) WithSuffix(suffix string) *ProductPriceTable {
+	return newProductPriceTable(a.SchemaName(), a.TableName()+suffix, a.TableName())
+}
+
+func newProductPriceTable(schemaName, tableName, alias string) *ProductPriceTable {
+	return &ProductPriceTable{
+		productPriceTable: newProductPriceTableImpl(schemaName, tableName, alias),
+		EXCLUDED:          newProductPriceTableImpl("", "excluded", ""),
+	}
+}
+
+func newProductPriceTableImpl(schemaName, tableName, alias string) productPriceTable {
+	var (
+		ProductIDColumn = postgres.StringColumn("product_id")
+		MethodColumn    = postgres.StringColumn("method")
+		CurrencyColumn  = postgres.StringColumn("currency")
+		AmountColumn    = postgres.IntegerColumn("amount")
+		allColumns      = postgres.ColumnList{ProductIDColumn, MethodColumn, CurrencyColumn, AmountColumn}
+		mutableColumns  = postgres.ColumnList{ProductIDColumn, MethodColumn, CurrencyColumn, AmountColumn}
+		defaultColumns  = postgres.ColumnList{}
+	)
+
+	return productPriceTable{
+		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
+
+		//Columns
+		ProductID: ProductIDColumn,
+		Method:    MethodColumn,
+		Currency:  CurrencyColumn,
+		Amount:    AmountColumn,
+
+		AllColumns:     allColumns,
+		MutableColumns: mutableColumns,
+		DefaultColumns: defaultColumns,
+	}
+}

backend/internal/postgres/jet/payments/table/table_use_schema.go

@@ -0,0 +1,23 @@
+//
+// Code generated by go-jet DO NOT EDIT.
+//
+// WARNING: Changes to this file may cause incorrect behavior
+// and will be lost if the code is regenerated
+//
+
+package table
+
+// UseSchema sets a new schema name for all generated table SQL builder types. It is recommended to invoke
+// this method only once at the beginning of the program.
+func UseSchema(schema string) {
+	Balances = Balances.FromSchema(schema)
+	Benefits = Benefits.FromSchema(schema)
+	CatalogAtom = CatalogAtom.FromSchema(schema)
+	Config = Config.FromSchema(schema)
+	Ledger = Ledger.FromSchema(schema)
+	Orders = Orders.FromSchema(schema)
+	PaymentEvents = PaymentEvents.FromSchema(schema)
+	Product = Product.FromSchema(schema)
+	ProductItem = ProductItem.FromSchema(schema)
+	ProductPrice = ProductPrice.FromSchema(schema)
+}

backend/internal/postgres/migrations/00010_payments_foundation.sql

@@ -0,0 +1,266 @@
+-- Payments data foundation: a self-contained `payments` schema for the in-game
+-- currency, wallets, benefits, catalog, orders and the append-only operations
+-- ledger. Nothing is wired to real money yet — this is the substrate the rest of
+-- the payments domain builds on. Mechanics live in docs/PAYMENTS.md.
+--
+-- Isolation. The schema is confined to a dedicated NOLOGIN role that holds ALL
+-- privileges on `payments.*` and none on `backend.*`; the backend application
+-- keeps its single (superuser) pool, so the DB grants are a stepping-stone to a
+-- future separate login/process rather than a runtime wall. The runtime wall is
+-- code-level: only the payments package reaches these tables (an import-boundary
+-- test guards it). There is deliberately NO cross-schema foreign key 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 account id — which keeps the domain extractable into its own database.
+--
+-- The ledger is append-only, enforced by a trigger (a superuser bypasses table
+-- privileges, so a REVOKE would not bind the application). Money is stored as an
+-- integer amount in the currency's minor units (RUB kopecks; Votes/Stars/chips
+-- are whole units, scale 1), never a float — integer-currency integrality is
+-- therefore structural.
+--
+-- Legacy note: backend.accounts.hint_balance and backend.accounts.paid_account
+-- are superseded by the segmented model here and are DEPRECATED. They are NOT
+-- dropped in this expand phase — reads still use them until the currency core
+-- flips them, and the DROP is a later contract-phase migration (image rollback
+-- must stay DB-safe). Neither was ever set in production.
+--
+-- Expand-contract: everything here is additive in its own schema, so a backend
+-- image rollback stays DB-safe (older code simply ignores the new schema).
+
+-- +goose Up
+
+CREATE SCHEMA IF NOT EXISTS payments;
+
+-- +goose StatementBegin
+DO $$
+BEGIN
+    IF NOT EXISTS (SELECT FROM pg_roles WHERE rolname = 'payments') THEN
+        CREATE ROLE payments NOLOGIN;
+    END IF;
+END
+$$;
+-- +goose StatementEnd
+
+GRANT USAGE ON SCHEMA payments TO payments;
+
+-- Base value types (atoms) a product is composed of. A fixed, code-known set.
+CREATE TABLE payments.catalog_atom (
+    atom_type text NOT NULL,
+    CONSTRAINT catalog_atom_pkey PRIMARY KEY (atom_type),
+    CONSTRAINT catalog_atom_type_chk
+        CHECK ((atom_type = ANY (ARRAY['chips'::text, 'hints'::text, 'noads_days'::text, 'tournament'::text])))
+);
+
+INSERT INTO payments.catalog_atom (atom_type) VALUES
+    ('chips'), ('hints'), ('noads_days'), ('tournament');
+
+-- A sellable product: a set of atoms at a price. Soft-deleted (deactivated),
+-- never removed, so historical orders/ledger keep resolving it.
+CREATE TABLE payments.product (
+    product_id uuid NOT NULL,
+    title text DEFAULT ''::text NOT NULL,
+    active boolean DEFAULT true NOT NULL,
+    created_at timestamp with time zone DEFAULT now() NOT NULL,
+    updated_at timestamp with time zone DEFAULT now() NOT NULL,
+    CONSTRAINT product_pkey PRIMARY KEY (product_id)
+);
+
+-- The atom composition of a product (e.g. 250 hints + 30 no-ads days).
+CREATE TABLE payments.product_item (
+    product_id uuid NOT NULL,
+    atom_type text NOT NULL,
+    quantity integer NOT NULL,
+    CONSTRAINT product_item_pkey PRIMARY KEY (product_id, atom_type),
+    CONSTRAINT product_item_product_fkey FOREIGN KEY (product_id)
+        REFERENCES payments.product (product_id) ON DELETE CASCADE,
+    CONSTRAINT product_item_atom_fkey FOREIGN KEY (atom_type)
+        REFERENCES payments.catalog_atom (atom_type),
+    CONSTRAINT product_item_quantity_chk CHECK ((quantity > 0))
+);
+
+-- Price of a product. A chip pack carries a money price per method
+-- (multi-currency Votes/Stars/RUB); a value carries a single chips price
+-- (currency='CHIP', method NULL). `amount` is an integer in the currency's
+-- minor units (RUB kopecks; Votes/Stars/chips whole, scale 1).
+CREATE TABLE payments.product_price (
+    product_id uuid NOT NULL,
+    method text,
+    currency text NOT NULL,
+    amount bigint NOT NULL,
+    CONSTRAINT product_price_product_fkey FOREIGN KEY (product_id)
+        REFERENCES payments.product (product_id) ON DELETE CASCADE,
+    CONSTRAINT product_price_method_chk
+        CHECK ((method IS NULL) OR (method = ANY (ARRAY['vk'::text, 'telegram'::text, 'direct'::text]))),
+    CONSTRAINT product_price_currency_chk
+        CHECK ((currency = ANY (ARRAY['RUB'::text, 'VOTE'::text, 'XTR'::text, 'CHIP'::text]))),
+    CONSTRAINT product_price_amount_chk CHECK ((amount >= 0))
+);
+
+-- One price row per (product, method, currency); NULL method (a value's chip
+-- price) collapses to one row via the COALESCE key.
+CREATE UNIQUE INDEX product_price_unique_idx
+    ON payments.product_price (product_id, COALESCE(method, ''::text), currency);
+
+-- A pre-created purchase intent. `expected_amount` is in `currency` minor units.
+CREATE TABLE payments.orders (
+    order_id uuid NOT NULL,
+    account_id uuid NOT NULL,
+    platform text NOT NULL,
+    product_id uuid NOT NULL,
+    expected_amount bigint NOT NULL,
+    currency text NOT NULL,
+    origin text NOT NULL,
+    status text DEFAULT 'pending'::text NOT NULL,
+    provider text,
+    provider_payment_id text,
+    created_at timestamp with time zone DEFAULT now() NOT NULL,
+    updated_at timestamp with time zone DEFAULT now() NOT NULL,
+    CONSTRAINT orders_pkey PRIMARY KEY (order_id),
+    CONSTRAINT orders_product_fkey FOREIGN KEY (product_id)
+        REFERENCES payments.product (product_id),
+    CONSTRAINT orders_status_chk
+        CHECK ((status = ANY (ARRAY['pending'::text, 'paid'::text, 'expired'::text]))),
+    CONSTRAINT orders_origin_chk
+        CHECK ((origin = ANY (ARRAY['vk'::text, 'telegram'::text, 'direct'::text]))),
+    CONSTRAINT orders_currency_chk
+        CHECK ((currency = ANY (ARRAY['RUB'::text, 'VOTE'::text, 'XTR'::text, 'CHIP'::text]))),
+    CONSTRAINT orders_expected_amount_chk CHECK ((expected_amount >= 0))
+);
+
+-- The pending-expiry sweep scans (status, created_at).
+CREATE INDEX orders_status_created_at_idx ON payments.orders (status, created_at);
+
+-- The append-only operations ledger: every fund / spend / admin_grant / refund.
+-- `chips_delta` is signed (0 for a grant, which credits values not chips);
+-- `snapshot` records the sold atoms + price for a spend/grant. Never updated or
+-- deleted (a trigger enforces it); a reversal is a new `refund` row.
+CREATE TABLE payments.ledger (
+    ledger_id uuid NOT NULL,
+    account_id uuid NOT NULL,
+    kind text NOT NULL,
+    source text,
+    origin text,
+    chips_delta integer DEFAULT 0 NOT NULL,
+    product_id uuid,
+    order_id uuid,
+    provider text,
+    provider_payment_id text,
+    snapshot jsonb,
+    created_at timestamp with time zone DEFAULT now() NOT NULL,
+    CONSTRAINT ledger_pkey PRIMARY KEY (ledger_id),
+    CONSTRAINT ledger_product_fkey FOREIGN KEY (product_id)
+        REFERENCES payments.product (product_id),
+    CONSTRAINT ledger_order_fkey FOREIGN KEY (order_id)
+        REFERENCES payments.orders (order_id),
+    CONSTRAINT ledger_kind_chk
+        CHECK ((kind = ANY (ARRAY['fund'::text, 'spend'::text, 'admin_grant'::text, 'refund'::text]))),
+    CONSTRAINT ledger_source_chk
+        CHECK ((source IS NULL) OR (source = ANY (ARRAY['vk'::text, 'telegram'::text, 'direct'::text]))),
+    CONSTRAINT ledger_origin_chk
+        CHECK ((origin IS NULL) OR (origin = ANY (ARRAY['vk'::text, 'telegram'::text, 'direct'::text])))
+);
+
+-- Idempotency key: a provider callback credits at most once. Partial so rows
+-- without a provider payment id (spend/admin_grant) are unconstrained.
+CREATE UNIQUE INDEX ledger_provider_payment_idx
+    ON payments.ledger (provider, provider_payment_id)
+    WHERE provider_payment_id IS NOT NULL;
+
+-- +goose StatementBegin
+CREATE FUNCTION payments.ledger_append_only() RETURNS trigger LANGUAGE plpgsql AS $$
+BEGIN
+    RAISE EXCEPTION 'payments.ledger is append-only: % denied', TG_OP;
+END;
+$$;
+-- +goose StatementEnd
+
+CREATE TRIGGER ledger_no_mutation
+    BEFORE UPDATE OR DELETE ON payments.ledger
+    FOR EACH ROW EXECUTE FUNCTION payments.ledger_append_only();
+
+-- Materialised chip balance, segmented by funding source. A fast cache of the
+-- ledger, recomputable from it; created lazily on first fund (up to three rows
+-- per account, absent = zero).
+CREATE TABLE payments.balances (
+    account_id uuid NOT NULL,
+    source text NOT NULL,
+    chips integer DEFAULT 0 NOT NULL,
+    updated_at timestamp with time zone DEFAULT now() NOT NULL,
+    CONSTRAINT balances_pkey PRIMARY KEY (account_id, source),
+    CONSTRAINT balances_source_chk
+        CHECK ((source = ANY (ARRAY['vk'::text, 'telegram'::text, 'direct'::text]))),
+    CONSTRAINT balances_chips_chk CHECK ((chips >= 0))
+);
+
+-- Materialised benefits, segmented by the purchase origin. no-ads is a duration
+-- (ads_paid_until) plus a perpetual override (ads_forever); hints is a count.
+-- Created lazily on first grant/spend.
+CREATE TABLE payments.benefits (
+    account_id uuid NOT NULL,
+    origin text NOT NULL,
+    ads_paid_until timestamp with time zone,
+    ads_forever boolean DEFAULT false NOT NULL,
+    hints integer DEFAULT 0 NOT NULL,
+    updated_at timestamp with time zone DEFAULT now() NOT NULL,
+    CONSTRAINT benefits_pkey PRIMARY KEY (account_id, origin),
+    CONSTRAINT benefits_origin_chk
+        CHECK ((origin = ANY (ARRAY['vk'::text, 'telegram'::text, 'direct'::text]))),
+    CONSTRAINT benefits_hints_chk CHECK ((hints >= 0))
+);
+
+-- The single-row tunable config (durations in whole seconds — go-jet stringifies
+-- interval; payouts as counts). Edited in the admin console, no release needed.
+CREATE TABLE payments.config (
+    only_row boolean DEFAULT true NOT NULL,
+    rewarded_payout_chips integer DEFAULT 0 NOT NULL,
+    cooldown_global_seconds integer DEFAULT 300 NOT NULL,
+    cooldown_vs_ai_seconds integer DEFAULT 1800 NOT NULL,
+    cooldown_hint_seconds integer DEFAULT 60 NOT NULL,
+    order_ttl_seconds integer DEFAULT 1800 NOT NULL,
+    CONSTRAINT config_pkey PRIMARY KEY (only_row),
+    CONSTRAINT config_single_row_chk CHECK (only_row)
+);
+
+INSERT INTO payments.config (only_row) VALUES (true);
+
+-- Payment lifecycle events for the dispatcher (live stream / botlink / email).
+CREATE TABLE payments.payment_events (
+    event_id uuid NOT NULL,
+    account_id uuid NOT NULL,
+    order_id uuid,
+    type text NOT NULL,
+    payload jsonb,
+    created_at timestamp with time zone DEFAULT now() NOT NULL,
+    dispatched_at timestamp with time zone,
+    CONSTRAINT payment_events_pkey PRIMARY KEY (event_id),
+    CONSTRAINT payment_events_order_fkey FOREIGN KEY (order_id)
+        REFERENCES payments.orders (order_id),
+    CONSTRAINT payment_events_type_chk
+        CHECK ((type = ANY (ARRAY['succeeded'::text, 'failed'::text, 'refunded'::text])))
+);
+
+CREATE INDEX payment_events_dispatch_idx
+    ON payments.payment_events (dispatched_at)
+    WHERE dispatched_at IS NULL;
+
+-- Confine the payments role to this schema: ALL on its tables, nothing on
+-- backend. New tables added later inherit the grant via default privileges.
+GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA payments TO payments;
+ALTER DEFAULT PRIVILEGES IN SCHEMA payments GRANT ALL ON TABLES TO payments;
+
+-- +goose Down
+
+ALTER DEFAULT PRIVILEGES IN SCHEMA payments REVOKE ALL ON TABLES FROM payments;
+DROP SCHEMA IF EXISTS payments CASCADE;
+
+-- +goose StatementBegin
+DO $$
+BEGIN
+    IF EXISTS (SELECT FROM pg_roles WHERE rolname = 'payments') THEN
+        EXECUTE 'DROP OWNED BY payments';
+        DROP ROLE payments;
+    END IF;
+END
+$$;
+-- +goose StatementEnd

backend/internal/robot/strategyfixture_test.go

@@ -0,0 +1,146 @@
+package robot
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"strconv"
+	"testing"
+
+	"scrabble/backend/internal/engine"
+)
+
+// The client-side offline robot (ui/src/lib/robot) reproduces the robot's move choice
+// so a local vs_ai game plays the same way as the server. These golden fixtures pin that
+// TS port to the real Go strategy. Being in-package, this emitter can exercise the
+// unexported mix / playToWin / deviates / selectMove that the port mirrors.
+
+type mixCase struct {
+	Seed  string `json:"seed"`
+	Salt  string `json:"salt"`
+	Nums  []int  `json:"nums"`
+	Value string `json:"value"` // the mix() uint64, as a decimal string (exceeds JS safe ints)
+}
+
+type decisionCase struct {
+	Seed       string `json:"seed"`
+	MoveCount  int    `json:"moveCount"`
+	MyScore    int    `json:"myScore"`
+	OppScore   int    `json:"oppScore"`
+	CandScores []int  `json:"candScores"`
+	RackLen    int    `json:"rackLen"`
+	BagLen     int    `json:"bagLen"`
+	PlayToWin  bool   `json:"playToWin"`
+	Win        bool   `json:"win"` // the per-turn intent after the deviate flip
+	Kind       string `json:"kind"`
+	Index      int    `json:"index"` // chosen candidate index for a play, else -1
+}
+
+type strategyFixture struct {
+	PlayToWinPercent int            `json:"playToWinPercent"`
+	Mix              []mixCase      `json:"mix"`
+	Decisions        []decisionCase `json:"decisions"`
+}
+
+// scenario is one selectMove situation exercised across several seeds.
+type scenario struct {
+	moveCount, myScore, oppScore, rackLen, bagLen int
+	cands                                         []int
+}
+
+// TestEmitStrategyFixtures regenerates ui/src/lib/robot/testdata/strategy.json. It is
+// gated by EMIT_STRATEGY_FIXTURES so a normal `go test` skips it; the committed output is
+// what the TS parity test consumes. Regenerate with:
+//
+//	EMIT_STRATEGY_FIXTURES=1 go test ./backend/internal/robot -run TestEmitStrategyFixtures
+func TestEmitStrategyFixtures(t *testing.T) {
+	if os.Getenv("EMIT_STRATEGY_FIXTURES") == "" {
+		t.Skip("set EMIT_STRATEGY_FIXTURES=1 to regenerate ui/src/lib/robot/testdata/strategy.json")
+	}
+
+	seeds := []int64{1, 42, -7, 1000003, 9999999999, 123456789, -123456789}
+
+	mixCases := []mixCase{}
+	addMix := func(seed int64, salt string, nums ...int) {
+		mixCases = append(mixCases, mixCase{
+			Seed:  strconv.FormatInt(seed, 10),
+			Salt:  salt,
+			Nums:  append([]int{}, nums...),
+			Value: strconv.FormatUint(mix(seed, salt, nums...), 10),
+		})
+	}
+	for _, sd := range seeds {
+		addMix(sd, "win")
+		addMix(sd, "deviate", 0)
+		addMix(sd, "deviate", 7)
+	}
+
+	scenarios := []scenario{
+		{3, 40, 55, 7, 20, []int{30, 12, 8}},   // behind, mid-game
+		{10, 120, 90, 7, 8, []int{25, 18, 5}},  // ahead, late
+		{1, 0, 0, 7, 30, []int{60, 30, 15, 7}}, // first move, big spread
+		{20, 200, 40, 5, 2, []int{50, 20}},     // big lead, bag near empty (no deviate)
+		{5, 30, 30, 7, 14, []int{20, 20, 20}},  // equal margins (tie-break)
+		{8, 50, 60, 7, 20, []int{}},            // no play, bag can refill -> exchange
+		{8, 50, 60, 3, 2, []int{}},             // no play, bag can't refill -> pass
+		{15, 300, 10, 7, 6, []int{80, 40, 10}}, // overshoots the band -> nearest to +30
+	}
+
+	decisions := []decisionCase{}
+	for _, sd := range seeds {
+		for _, sc := range scenarios {
+			cands := make([]engine.MoveRecord, len(sc.cands))
+			for i, s := range sc.cands {
+				cands[i] = engine.MoveRecord{Score: s, Player: i}
+			}
+			rack := make([]string, sc.rackLen)
+			for i := range rack {
+				rack[i] = "a"
+			}
+
+			ptw := playToWin(sd)
+			win := ptw
+			if deviates(sd, sc.moveCount, sc.bagLen) {
+				win = !win
+			}
+			d := selectMove(cands, sc.myScore, sc.oppScore, win, defaultBand, rack, sc.bagLen)
+
+			kind, index := "pass", -1
+			switch d.kind {
+			case decidePlay:
+				kind, index = "play", d.move.Player
+			case decideExchange:
+				kind = "exchange"
+			}
+
+			decisions = append(decisions, decisionCase{
+				Seed:       strconv.FormatInt(sd, 10),
+				MoveCount:  sc.moveCount,
+				MyScore:    sc.myScore,
+				OppScore:   sc.oppScore,
+				CandScores: append([]int{}, sc.cands...),
+				RackLen:    sc.rackLen,
+				BagLen:     sc.bagLen,
+				PlayToWin:  ptw,
+				Win:        win,
+				Kind:       kind,
+				Index:      index,
+			})
+		}
+	}
+
+	fx := strategyFixture{PlayToWinPercent: playToWinPercent, Mix: mixCases, Decisions: decisions}
+	dir := filepath.Join("..", "..", "..", "ui", "src", "lib", "robot", "testdata")
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		t.Fatalf("mkdir %s: %v", dir, err)
+	}
+	data, err := json.MarshalIndent(fx, "", "  ")
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+	path := filepath.Join(dir, "strategy.json")
+	if err := os.WriteFile(path, append(data, '\n'), 0o644); err != nil {
+		t.Fatalf("write %s: %v", path, err)
+	}
+	t.Logf("wrote %s (%d mix, %d decisions)", path, len(mixCases), len(decisions))
+}

backend/internal/server/banner.go

@@ -8,6 +8,7 @@ import (
 
 	"scrabble/backend/internal/account"
 	"scrabble/backend/internal/ads"
+	"scrabble/backend/internal/engine"
 	"scrabble/backend/internal/notify"
 )
 
@@ -56,9 +57,34 @@ func (s *Server) profileResponse(ctx context.Context, acc account.Account) profi
 	r := profileResponseFor(acc)
 	r.Banner = s.bannerFor(ctx, acc)
 	s.fillLinkedIdentities(ctx, &r, acc.ID)
+	r.DictVersions = s.currentDictVersions()
 	return r
 }
 
+// currentDictVersions reports the current dictionary version of every game variant with a
+// resident dictionary, as engine.Variant stable labels. It backs profileResponse.DictVersions
+// so an offline-capable client preloads the matching dawg per variant off the cold-start
+// profile. A variant without a loaded dictionary is omitted (Registry.Latest reports
+// ErrUnknownVariant); the returned slice is nil only when no variant is resident.
+func (s *Server) currentDictVersions() []dictVersion {
+	if s.registry == nil {
+		return nil // no dictionary registry wired (e.g. a minimal test server): advertise none
+	}
+	variants := []engine.Variant{engine.VariantEnglish, engine.VariantRussianScrabble, engine.VariantErudit}
+	out := make([]dictVersion, 0, len(variants))
+	for _, v := range variants {
+		version, _, err := s.registry.Latest(v)
+		if err != nil {
+			continue
+		}
+		out = append(out, dictVersion{Variant: v.String(), Version: version})
+	}
+	if len(out) == 0 {
+		return nil
+	}
+	return out
+}
+
 // fillLinkedIdentities sets the profile's confirmed email address and platform-linked
 // flags from the account's identities, so the client offers the right link / unlink /
 // change-email controls. A read failure leaves them zero (no controls), logged as a

backend/internal/server/dto.go

@@ -63,6 +63,20 @@ type profileResponse struct {
 	Email          string `json:"email"`
 	TelegramLinked bool   `json:"telegram_linked"`
 	VkLinked       bool   `json:"vk_linked"`
+	// DictVersions lists the current dictionary version per game variant (engine.Variant
+	// stable labels). An installed PWA preparing for offline play reads it to preload the
+	// right dawg per enabled variant off this cold-start response, without an extra request.
+	// Filled outside the pure projection (it reads the dictionary registry), so it is empty
+	// for callers that build the DTO without a Server. See Server.profileResponse.
+	DictVersions []dictVersion `json:"dict_versions,omitempty"`
+}
+
+// dictVersion pairs a game variant's stable label (engine.Variant.String) with its current
+// dictionary version. profileResponse.DictVersions carries the set so an offline-capable
+// client preloads the matching dawg per variant.
+type dictVersion struct {
+	Variant string `json:"variant"`
+	Version string `json:"version"`
 }
 
 // tileDTO is one placed (or to-place) tile.
@@ -149,13 +163,16 @@ type alphabetEntryDTO struct {
 // stateDTO is a player's view of a game. Rack carries wire alphabet indices (a
 // blank is engine.BlankIndex). Alphabet is present only when the request asked for it.
 type stateDTO struct {
-	Game           gameDTO            `json:"game"`
-	Seat           int                `json:"seat"`
-	Rack           []int              `json:"rack"`
-	BagLen         int                `json:"bag_len"`
-	HintsRemaining int                `json:"hints_remaining"`
-	WalletBalance  int                `json:"wallet_balance"`
-	Alphabet       []alphabetEntryDTO `json:"alphabet,omitempty"`
+	Game           gameDTO `json:"game"`
+	Seat           int     `json:"seat"`
+	Rack           []int   `json:"rack"`
+	BagLen         int     `json:"bag_len"`
+	HintsRemaining int     `json:"hints_remaining"`
+	WalletBalance  int     `json:"wallet_balance"`
+	// HintUnlockLeftSeconds is the vs_ai idle-hint gate: seconds until the hint unlocks (0 for a human
+	// game / first move / not your turn). The client anchors a monotonic countdown to it.
+	HintUnlockLeftSeconds int                `json:"hint_unlock_left_seconds"`
+	Alphabet              []alphabetEntryDTO `json:"alphabet,omitempty"`
 }
 
 // matchDTO reports whether the caller has been paired into a game.
@@ -301,12 +318,13 @@ func stateDTOFrom(v game.StateView, includeAlphabet bool) (stateDTO, error) {
 		return stateDTO{}, err
 	}
 	dto := stateDTO{
-		Game:           gameDTOFromGame(v.Game),
-		Seat:           v.Seat,
-		Rack:           rack,
-		BagLen:         v.BagLen,
-		HintsRemaining: v.HintsRemaining,
-		WalletBalance:  v.WalletBalance,
+		Game:                  gameDTOFromGame(v.Game),
+		Seat:                  v.Seat,
+		Rack:                  rack,
+		BagLen:                v.BagLen,
+		HintsRemaining:        v.HintsRemaining,
+		WalletBalance:         v.WalletBalance,
+		HintUnlockLeftSeconds: v.HintUnlockLeftSeconds,
 	}
 	if includeAlphabet {
 		tab, err := engine.AlphabetTable(v.Game.Variant)

backend/internal/server/handlers.go

@@ -239,6 +239,9 @@ func statusForError(err error) (int, string) {
 		return http.StatusConflict, "no_hint_available"
 	case errors.Is(err, game.ErrHintsDisabled), errors.Is(err, game.ErrNoHintsLeft):
 		return http.StatusConflict, "hint_unavailable"
+	case errors.Is(err, game.ErrHintLocked):
+		// A vs_ai idle hint is still gated (the server-clock backstop); the client shows the lock.
+		return http.StatusConflict, "hint_locked"
 	case errors.Is(err, engine.ErrIllegalPlay), errors.Is(err, engine.ErrTilesNotOnRack), errors.Is(err, engine.ErrGameOver):
 		return http.StatusUnprocessableEntity, "illegal_play"
 	case errors.Is(err, account.ErrEmailTaken), errors.Is(err, account.ErrIdentityTaken):

backend/internal/server/server.go

@@ -28,6 +28,7 @@ import (
 	"scrabble/backend/internal/link"
 	"scrabble/backend/internal/lobby"
 	"scrabble/backend/internal/notify"
+	"scrabble/backend/internal/payments"
 	"scrabble/backend/internal/ratewatch"
 	"scrabble/backend/internal/render"
 	"scrabble/backend/internal/session"
@@ -93,6 +94,11 @@ type Deps struct {
 	// profile.get banner block, plus the banner admin console section. A nil Ads
 	// omits the banner block and disables the banner console.
 	Ads *ads.Service
+	// Payments is the in-game currency domain service (wallet, benefits, catalog).
+	// The data-foundation layer exposes only a reachability check; its user and
+	// console routes are registered when the wallet surface lands. A nil Payments
+	// omits them.
+	Payments *payments.Service
 	// Notifier publishes live-event intents — here the banner-eligibility re-poll
 	// signal the banner/hint/role console actions emit. A nil Notifier discards
 	// them (notify.Nop).
@@ -129,6 +135,7 @@ type Server struct {
 	ratewatch   *ratewatch.Watch
 	banview     *banview.View
 	ads         *ads.Service
+	payments    *payments.Service
 	notifier    notify.Publisher
 	console     *adminconsole.Renderer
 	exportKey   []byte
@@ -181,6 +188,7 @@ func New(addr string, deps Deps) *Server {
 		ratewatch:     deps.RateWatch,
 		banview:       deps.BanView,
 		ads:           deps.Ads,
+		payments:      deps.Payments,
 		notifier:      notifier,
 		renderer:      deps.Renderer,
 		http:          &http.Server{Addr: addr, Handler: engine},

docs/ARCHITECTURE.md

@@ -1238,12 +1238,74 @@ separate site; the SPA shell is `noindex`, and the landing always boots in Russi
 browser-language detection — crawlers render with arbitrary languages). The favicon set,
 `og-image.png` and `robots.txt` ship unhashed from `ui/public/` (generated by
 `assets/icons/`, same tile design as the VK loader). On the web (`/app/`) the SPA is an installable **PWA**:
-`manifest.webmanifest` and an install-only **service worker** (`sw.js`) ship unhashed from
-`ui/public/`, and the client registers the worker **web-only** — never inside a Mini App or the
-mock build. The worker intercepts only top-level navigations (network-first with a cached-shell
-fallback), leaving `/assets/*` and the Connect stream untouched; it exists to satisfy Chromium's
-installability requirement (a registered SW, needed for install on Android) and is the single
-growth point for a future opt-in offline mode. The gateway registers the `.webmanifest` MIME type
+`manifest.webmanifest` ships unhashed from `ui/public/`, while the **service worker** (`sw.js`) is
+built from `ui/src/sw.ts` by **vite-plugin-pwa** (injectManifest strategy) — the client registers it
+**web-only**, never inside a Mini App or the mock build (the plugin is disabled there entirely). It
+**precaches the app shell and the hashed assets** (Workbox) so an installed PWA cold-launches with
+no network. Shell **navigations are network-first** — the fresh `no-cache` shell is fetched from the
+server (so a new deploy is picked up on the very next launch, not the one after), falling back to the
+precached shell only when the network is unreachable or too slow; the immutable hashed assets stay
+cache-first, and the hash router resolves the route client-side. This navigation route is registered
+**before** the precache route on purpose: Workbox matches in registration order, and the precache
+route (its `directoryIndex` is `index.html`) would otherwise shadow it and serve the shell
+cache-first — the old build's version until a second load. The landing page and the conditional
+polyfill bundle are excluded, and the Connect stream and runtime API POSTs are never precached nor
+intercepted, so the live app is never served stale. This satisfies Chromium's installability requirement (a registered SW, needed
+for install on Android) and powers the opt-in **offline mode** (in progress): a deliberate, device-scoped Settings
+toggle — distinct from the transient gateway-reachability signal — that tints the header blue with
+an *Offline* chip and confines play to on-device `vs_ai` games. The **offline lobby lists only those
+device-local games** (reconstructed by replaying the IndexedDB move journal) and its New-vs-AI entry
+creates one through the in-browser engine — the same game screen then drives it, the robot replying
+locally; online-only affordances (the Stats tab, the random-opponent option) are disabled
+or hidden, and New Game's *with friends* becomes the entry to **local pass-and-play (hotseat)**.
+A hotseat game is a device-local **2-4 human** game built through the same engine (`hotseat` +
+per-seat/host PIN locks on the record; the seats carry names but no accounts). A **mandatory host
+(referee) PIN** gates the roster at creation and, in-game, the referee overrides — **skip** the
+current turn, **exclude** a player (a forced seat resign, `resignSeat`) or **terminate** the game
+(deleted, no winner/loser); each seat may also carry its own **optional PIN** that withholds its rack
+(the board stays visible — only the tray is gated) until it is entered, so players pass the device
+around freely and lock a seat only against a distrusted tablemate. The unlock is **per turn**
+(re-locks on advance). PINs are a **social lock, not cryptography** — a salted SHA-256 kept only in
+the device record (`lib/pin`); a 4-digit PIN is trivially brute-forceable and the racks live in
+client memory regardless, so they defeat a casual glance, not a determined peek. A hotseat game is
+**not `vs_ai`**: hints (the freed control becomes the host button) and chat/self-resign are gone, and
+its lobby card — active *and* finished — is master-PIN-gated to delete (so the last mover cannot
+instantly wipe it); a naturally finished game is saved with its result like any local game. A `vs_ai`
+hint (online and offline alike) is unlimited and wallet-free but idle-gated
+(unlocked ~30 min into a stuck turn), and counts toward no hint statistic. The **source** reports the
+**seconds left** (`hint_unlock_left_seconds` on the game view) — computed by the **backend from the
+server clock** online (which also enforces the gate, returning `hint_locked` for an early request),
+and by the offline source from the device clock (persisted, capped at the window). The **client
+anchors a MONOTONIC countdown** (`performance.now()`, `lib/hints`) to that seconds-left when it lands
+(on load, and to the full window when the robot moves), so a client clock change cannot skew it, and
+a relaunch re-reads a fresh value so the wait is not forgotten. To have data ready before the switch, the **Profile advertises the current dictionary
+version per variant** (`dict_versions`,
+filled from the registry on the existing cold-start profile request — no extra round-trip), and an
+eligible installed PWA (standalone web + confirmed email) **background-preloads** those dictionaries
+— on lobby entry and on a variant-preference change — through the same three-tier loader, retried
+with backoff and honouring the session miss-breaker; the move generator, the loader and the preload
+orchestration stay in lazy chunks. A first-lobby preload failure shows a *poor-connection* notice in
+the ad-banner slot. Flipping the Settings toggle **to** offline runs that same cache-first fetch
+bounded by a ~5 s UI wait (`raceOfflineReady` + the lazy `dict/offlineready`): it enters offline only
+once every enabled variant is ready, otherwise it stays online with a *needs internet* note while the
+fetch finishes in the background (the next flip is then instant). A **cold launch already in offline
+mode** boots from the persisted session and
+profile (the profile is saved on every online adopt/refresh) — `bootstrap` skips the session
+adoption and profile fetch that would otherwise hang with no network, and lands straight in the
+offline lobby; without a cached profile (an install that was never online) it drops the sticky flag
+and boots online instead. Beyond the sticky toggle the app **auto-detects connectivity**: the
+reactive flag carries an *auto* bit, so a self-entered offline (no network) is transient
+(session-only, never persisted) and self-heals to online when the network returns, while a deliberate
+one (the toggle, or the cold-start dialog's *Switch*) persists. At cold start `navigator.onLine ===
+false` enters offline for the session; otherwise a single bounded reachability probe (a `profile.get`,
+~3 s) decides — success boots online, a timeout on an eligible install raises a *No connection* dialog
+(*Switch* = sticky offline, *Wait for network* = boot online with the reachability watcher retrying).
+Mid-session the `window` `online`/`offline` events drive it — `offline` auto-enters, `online`
+re-verifies reachability before returning — backed by a `navigator.onLine` poll because those events
+are unreliable on some platforms (notably iOS PWAs). Offline is a real **transport kill switch**
+(every gateway call is refused, so no traffic leaks); the reachability probe is the one call exempt
+from it (it is the return-to-online mechanism), and the transient reachability watcher is suppressed
+while offline. The gateway registers the `.webmanifest` MIME type
 in-process (the distroless image has no `/etc/mime.types`). Hash-named `/assets/*` are served
 `immutable` (a relaunch is a cache hit, not a re-download); the HTML shells are
 `no-cache` so a new deploy is picked up — both containers apply the same caching. An

docs/FUNCTIONAL.md

@@ -215,7 +215,16 @@ unlimited and offers a complaint on any result; for a word it finds, it also lin
 external reference dictionary (gramota.ru for Russian games, scrabblewordfinder.org for
 English) to look it up. Hints are governed per game —
 whether they are allowed and how many each player starts with — and draw on a
-personal hint wallet once the per-game allowance is spent. The game ends when the
+personal hint wallet once the per-game allowance is spent. Against the robot
+(**vs_ai**) hints are instead **unlimited and wallet-free**, but idle-gated as an
+anti-frustration aid: one unlocks only after the player has been **stuck ~30 minutes
+on a turn** (timed from the robot's last move; the very first move, before the robot
+has played, is exempt). While gated the hint button carries a small **🔒 lock** and a
+tap shows how long remains; the lock lifts live at the mark. The same gate applies **online and
+offline**: the countdown runs on a **steady in-app timer**, not the device clock, so changing the
+clock cannot skew it, and a relaunch re-reads the remaining time so a stuck turn is not forgotten.
+Online the **server enforces** it from its own clock (which the player cannot touch); a vs_ai hint
+counts toward no hint statistic. The game ends when the
 bag empties and a player clears their rack, after 6 consecutive scoreless turns,
 by resignation, or by the per-game move timeout (5 minutes to 24 hours, default
 24 hours): a missed turn auto-resigns, except while the player is inside their
@@ -256,6 +265,44 @@ the same occasional move against its plan that fades out by the endgame), and ch
 add-friend are off. AI games are **practice** — they never count toward a player's
 statistics.
 
+### Offline mode
+An installed web PWA signed in with a confirmed email can switch to a deliberate **offline mode**
+(Settings → Play mode). Offline, the app never touches the network: the header turns blue with an
+*Offline* chip, the lobby lists only the games stored on the device, and online-only surfaces are
+disabled or hidden (the Stats tab; the *random opponent* option in New Game).
+A New Game against the robot creates a device-local **vs_ai** game — it
+plays entirely in the browser with no backend. Local games are kept on the device, visible only in
+offline mode, and never sync to the account. So a game can be created and played with no connection,
+the app quietly preloads the dictionaries for the player's enabled variants while still online, and
+(once installed) launches from a precached shell even with no network. Switching **to** offline first
+checks that the enabled variants' dictionaries are on the device — if any are missing it fetches them
+and waits briefly, and if they cannot be readied it stays online with a short *needs internet* note
+(the download keeps running in the background, so a later switch is instant). The mode is
+device-scoped and sticky across launches.
+
+Offline, New Game's **with friends** starts a **local pass-and-play** game for 2-4 people sharing one
+device. You first set a **host (leader) password** — a 4-digit PIN entered on a lock-screen-style
+keypad; until it is set the player rows stay locked. The app then asks whether you are playing too —
+if so you take the first seat with your profile name. You name each player (2 to 4; add or remove
+rows, where a removal asks for the leader password) and may give any seat its **own optional PIN**.
+During the game the board is always visible, but a PIN-locked seat shows an **Unlock** button in place
+of its rack until its owner enters the PIN — so the device passes hand to hand and only a protected
+seat hides its letters; the lock returns each turn. The **leader** (the host button in the game) can,
+with the leader password, **skip** the current player's turn, **remove** a player, or **end the game
+early** — an early end discards the game with no winner or loser. Hints and chat are off in a
+pass-and-play game. A game that finishes normally is saved to the offline lobby like any other;
+deleting any pass-and-play game — running or finished — from the lobby asks for the leader password,
+so no one can wipe a game the moment they have moved.
+
+The app also **enters offline mode on its own** when it cannot reach the network. On a cold launch
+with no connection it switches to offline for that session; when the device is online but the gateway
+stays silent for a few seconds it asks first — *No connection. Switch to offline mode?*, with
+**Switch** (go offline) or **Wait for network** (keep retrying online). While the app is open, losing
+the network — airplane mode — switches to offline automatically, and restoring it returns online by
+itself. A self-entered offline is temporary: it reverts to online the moment the network is back, and
+the next launch re-checks. A **deliberate** offline — the Settings toggle, or **Switch** in that
+dialog — is the player's choice: it is kept, and never undone automatically.
+
 ### Social: friends, block, chat, nudge
 Become friends in two ways: redeem a **one-time code** the other player issues (six
 digits, valid for twelve hours), or send a **request to someone you have played

docs/FUNCTIONAL_ru.md

@@ -222,7 +222,16 @@ e-mail) либо ввод фразы. Активные игры форфейтя
 внешний справочный словарь (gramota.ru для русских игр, scrabblewordfinder.org для английских),
 чтобы его посмотреть. Подсказки управляются настройками
 партии — разрешены ли они и сколько их у каждого игрока на старте — и расходуют
-личный кошелёк подсказок после исчерпания внутриигрового лимита. Партия
+личный кошелёк подсказок после исчерпания внутриигрового лимита. Против робота
+(**vs_ai**) подсказки, наоборот, **безлимитны и без кошелька**, но с idle-гейтом как
+анти-фрустрация: подсказка открывается, только когда игрок **застрял на ходу ~30 минут**
+(отсчёт от последнего хода робота; самый первый ход, до хода робота, исключён). Пока гейт
+закрыт, кнопка подсказки несёт маленький **🔒 замок**, а тап показывает, сколько осталось;
+замок снимается вживую в нужный момент. Один и тот же гейт работает **онлайн и офлайн**: отсчёт
+идёт по **ровному внутриигровому таймеру**, а не по системным часам, поэтому их перевод его не
+собьёт, а повторный вход перечитывает остаток — застрявший ход не забывается. Онлайн гейт
+**принуждает сервер** по своим часам (их игрок не тронет); vs_ai-подсказка не учитывается ни в
+одной статистике подсказок. Партия
 завершается, когда мешок пуст и игрок выложил стойку, после 6 подряд бесплодных
 ходов, по сдаче, либо по таймауту хода (от 5 минут до 24 часов, дефолт 24 часа):
 пропущенный ход означает авто-сдачу, кроме как когда игрок внутри своего
@@ -261,6 +270,45 @@ e-mail) либо ввод фразы. Активные игры форфейтя
 паузы), сохраняет ту же силу (по-прежнему играет на победу лишь примерно в 40% партий, с теми же
 редкими ходами вопреки плану, затухающими к эндшпилю), а чат, nudge и «добавить в друзья» выключены. Партии с ИИ — это **тренировка**: они не идут в статистику игрока.
 
+### Офлайн-режим
+Установленный веб-PWA со входом по подтверждённой почте может переключиться в осознанный
+**офлайн-режим** (Настройки → Режим игры). В офлайне приложение не обращается к сети: шапка синеет с
+меткой *Офлайн*, лобби показывает только сохранённые на устройстве игры, а сетевые поверхности
+отключены или скрыты (вкладка Статистика; вариант «случайный соперник» в Новой игре).
+Новая игра против робота создаёт локальную **vs_ai**-игру — он ходит
+целиком в браузере без бэкенда. Локальные игры хранятся на устройстве, видны только в офлайн-режиме и
+никогда не синхронизируются с аккаунтом. Чтобы игру можно было создать и сыграть без связи, приложение
+заранее, пока ещё онлайн, подгружает словари включённых игроком вариантов и (после установки)
+запускается из прекешированного шелла даже без сети. Переключение **в** офлайн сначала проверяет, что
+словари включённых вариантов есть на устройстве — если каких-то не хватает, оно их подгружает и недолго
+ждёт, а если подготовить их не удаётся, остаётся онлайн с короткой заметкой *нужен интернет* (загрузка
+продолжается в фоне, так что следующее переключение мгновенно). Режим привязан к устройству и
+сохраняется между запусками.
+
+В офлайне «с друзьями» в Новой игре запускает **локальную игру по очереди (hotseat)** на 2–4 человек
+за одним устройством. Сначала задаётся **пароль ведущего** — 4-значный PIN на клавиатуре в стиле
+экрана блокировки; пока он не задан, строки игроков заблокированы. Затем приложение спрашивает,
+играете ли вы сами — если да, вы занимаете первое место под именем из профиля. Вы называете каждого
+игрока (от 2 до 4; строки можно добавлять и удалять, удаление спрашивает пароль ведущего) и можете
+дать любому месту **свой необязательный PIN**. Во время игры доска видна всегда, но место с PIN
+вместо стойки показывает кнопку **«Разблокировать»**, пока владелец не введёт PIN, — так устройство
+передаётся из рук в руки, и только защищённое место прячет свои буквы; на каждом ходу замок
+возвращается. **Ведущий** (кнопка ведущего в игре) может по паролю ведущего **пропустить** ход
+текущего игрока, **исключить** игрока или **завершить игру досрочно** — досрочное завершение стирает
+партию без победителей и проигравших. Подсказки и чат в игре по очереди отключены. Нормально
+завершённая партия сохраняется в офлайн-лобби как любая другая; удаление любой игры по очереди —
+идущей или завершённой — из лобби спрашивает пароль ведущего, чтобы никто не стёр партию сразу после
+своего хода.
+
+Приложение также **само включает офлайн-режим**, когда не может достучаться до сети. При холодном
+запуске без связи оно переходит в офлайн на текущую сессию; когда устройство онлайн, но шлюз молчит
+несколько секунд, оно сперва спрашивает — *Нет связи. Включить офлайн-режим?*, с выбором **Включить**
+(уйти в офлайн) или **Ждать сеть** (продолжить попытки онлайн). Пока приложение открыто, потеря сети —
+режим полёта — переключает в офлайн автоматически, а её восстановление само возвращает онлайн.
+Самостоятельно включённый офлайн временный: он возвращается в онлайн, как только сеть появилась, и
+следующий запуск проверяет заново. **Осознанный** офлайн — тумблер в Настройках или **Включить** в том
+диалоге — это выбор игрока: он сохраняется и никогда не отменяется автоматически.
+
 ### Социальное: друзья, блок, чат, nudge
 Подружиться можно двумя способами: погасить **одноразовый код**, который выпускает
 другой игрок (шесть цифр, действует двенадцать часов), либо отправить **заявку

docs/PAYMENTS.md

@@ -0,0 +1,338 @@
+# PAYMENTS — monetization mechanics
+
+Authoritative specification of the monetization domain: the in-game currency, wallets,
+benefits, store-compliance rules, payment intake, ads, catalog, ledger, and reporting.
+English is authoritative; [`PAYMENTS_ru.md`](PAYMENTS_ru.md) mirrors it in plain Russian
+(mirror every point edit in the same PR, like `FUNCTIONAL.md`/`FUNCTIONAL_ru.md`).
+
+Read this before changing any payments behaviour. The technical implementation plan lives
+in [`../PLAN.md`](../PLAN.md).
+
+> Status: specification approved; implementation staged (see `PLAN.md`). Nothing here is
+> live yet.
+
+## 1. Overview
+
+The game earns through two orthogonal channels:
+
+- **Purchases** of the in-game currency **Фишка** (chips) with real money, then spending
+  chips on **values** (benefits).
+- **Ads** — a rewarded video tops chips up; an interstitial and a house banner monetize by
+  impression.
+
+The currency is **two-tier**:
+
+```
+money (VK Votes / TG Stars / RUB via Robokassa)  ─┐
+                                                  ├─►  Фишки (chips)  ──►  values
+rewarded ad view                                 ─┘                         (no-ads, hints,
+                                                                             tournament fee)
+```
+
+Chips are the single storefront unit. Money and rewarded views **fund** chips; chips
+**buy** values. There is no path that spends money directly on a value — always through
+chips.
+
+## 2. Currency model
+
+**One chip is one chip everywhere** — the unit is uniform. The difference between payment
+methods lives entirely in the **purchase rate**: a chip pack costs *X* Votes / *Y* Stars /
+*Z* RUB, and the rate absorbs each store's commission. Value prices are fixed **in chips**
+and identical across methods.
+
+The chip balance is **segmented by `source`** — the platform where the chips were funded:
+
+| `source`   | Funded by                        |
+|------------|----------------------------------|
+| `vk`       | VK Votes purchase, VK rewarded ad |
+| `telegram` | TG Stars purchase                |
+| `direct`   | Robokassa purchase (web / native)|
+
+A single account holds all three segments simultaneously: `balance = (account_id, source)`,
+up to three rows — a row is materialised lazily on the segment's first funding, and an absent
+segment reads as zero. Segmentation is **not** per-identity — see §6.
+
+Why segmented, not one pooled balance: store rules forbid activating value that was paid
+for outside the store's own cash desk. Chips funded inside VK (Votes) may only be spent in
+the VK context; Stars only inside Telegram; Robokassa-funded (`direct`) chips only outside
+the stores. See §4.
+
+## 3. Three operations, kept distinct
+
+Do not conflate these — they use different keys:
+
+1. **Fund chips** — money/ad → chip `source` segment, keyed by the **execution context**.
+2. **Spend chips = buy a value** — segment → benefit, keyed by context with the gate (§4).
+   This is where a benefit is **born** and stamped with its `origin`.
+3. **Apply a benefit** over time (e.g. "no-ads until *T*") — governed by the origin rule
+   (§5).
+
+`source` (where chips were funded) and `origin` (where a value was bought) share the same
+value set `{vk, telegram, direct}` but mean different things. On the web they can diverge:
+web spending may draw `vk` chips (`source=vk`) into a `direct` purchase (`origin=direct`).
+
+## 4. Store-compliance gate
+
+The compliance wall is **one-directional**. The dangerous direction — activating externally
+paid value *inside* a store wrapper — is blocked; the safe direction (a store benefit
+leaking out to the open web) is allowed.
+
+**Spend context → which segments/benefits are usable:**
+
+| Execution context   | Spendable chip segments | Spend priority     |
+|---------------------|-------------------------|--------------------|
+| Inside VK (Android) | `vk`                    | —                  |
+| Inside VK (iOS)     | none — frozen (view only)| —                 |
+| Inside Telegram     | `telegram`              | —                  |
+| Web / native (Direct)| `direct` + `vk` + `telegram` | direct → vk → tg |
+
+- Inside VK/TG only the same-named segment is usable; everything else (chiefly `direct`) is
+  invisible-as-spendable there.
+- On the web the store has no jurisdiction, so all attached segments are spendable, drained
+  by priority direct → vk → tg.
+- **VK iOS** is frozen for spending (Apple forbids spending virtual currency on digital
+  goods outside IAP inside VK on iOS): the balance is shown as a number, but no purchase or
+  spend is possible. A previously bought benefit still *applies* there.
+
+The account is **single** (identities merge, one profile/friends/stats). The gate is
+**logical**: in a VK/TG context the server activates only the same-named segment. It rests
+on a **trusted platform signal** (§8) — the client is never believed. When the platform
+cannot be trusted, the gate is **fail-closed**: spends/purchases are denied, view only.
+
+### One-directional benefit application
+
+A benefit carries `origin` = the **purchase context** (not "what it was paid with"). Buying
+on the web with `vk` chips still yields `origin=direct`.
+
+| `origin`         | Where the benefit applies                          |
+|------------------|----------------------------------------------------|
+| `vk` / `telegram`| **Everywhere** — inside its store *and* out on web/native |
+| `direct`         | **Only** web/native — never inside VK/TG (= store ban) |
+
+Before a web spend draws `vk`/`telegram` chips, the UI **warns** the user that the value
+will be available here (web/native) only, because of VK/TG restrictions.
+
+## 5. Benefits
+
+Three distinct entities, do not merge:
+
+- **Chips** — currency. Segment by `source`.
+- **Hints** — consumable, bought with chips. Segment by `origin`. Spent one-per-hint in
+  online games; `vs_ai` hints stay free/unlimited (30-min idle gate, not counted). A hint
+  spent in a game is drawn from an `origin` applicable to the current context (same
+  one-directional relaxation as above).
+- **No-ads** — a duration benefit, bought with chips. Segment by `origin`.
+
+**No-ads stacking.** Buying a term extends `paid_until[origin] += term` from
+`max(now, current end)` — the remainder is never lost ("terms add up"). **Forever** is a
+separate perpetual flag that overrides terms. "Ads off in context *P*" ⇔ some `origin`
+applicable in *P* has `paid_until > now` (on the web take the max over direct/vk/tg; in VK
+only vk; in TG only tg).
+
+**What no-ads suppresses:** the top banner **and** the post-move fullscreen interstitial.
+The voluntary **rewarded** view (for chips) is never suppressed — it is the user's choice.
+
+**Tournament fee** — a future value type; the atom is provisioned but the mechanic ships
+later.
+
+## 6. Wallet lifecycle
+
+**Segment availability rule.** A segment is spendable ⇔ the account has an identity of that
+`source` (for `direct`: a durable identity/email). This makes unlink/merge fall out
+naturally.
+
+**Unlink (vk/tg).** Allowed even with a non-zero balance/active benefit. The segment is not
+burned — it **sleeps** (no identity ⇒ unavailable in VK *and*, lacking the attachment,
+unavailable as an attached web segment); re-linking wakes it. The user is warned before
+unlinking ("N chips will be unavailable until you re-link"). The last identity cannot be
+unlinked (existing `ErrLastIdentity`).
+
+**Merge.** Segments and benefits merge **by origin**: same-origin segments add (chips sum,
+benefit terms extend per origin), different origins coexist. This extends the current
+account-merge (`hint_balance +=`, `paid_account OR=`) so origin is preserved and nothing
+leaks across platforms.
+
+**Guest.** A guest account has **no wallet at all** — the Wallet section is hidden, no
+purchases, no balance, by design. Balances belong only to durable accounts. The guest
+reaper therefore deletes guests freely (no money can exist there). In `direct`, email is
+required **before the first purchase** as a recovery anchor (in VK/TG the vk/tg identity is
+already the anchor); the existing email flow (request code → confirm → clear guest →
+durable) is reused.
+
+## 7. Catalog and pricing
+
+The catalog is **configurable** — products, prices, purchase rates, and rewarded payout
+live in the database and are edited in the admin console, no release required.
+
+- **Base values (atoms):** chips, hints, no-ads days, tournament entry.
+- **Product = a set of atoms + a price.** Sold singly or as a combo (e.g. "250 hints + 30
+  no-ads days").
+- **Chip pack** (funds chips) — priced **per method** (multi-currency Votes/Stars/RUB) as a
+  single product.
+- **Value** (bought with chips) — priced **in chips** (uniform across methods).
+
+**Deactivation, not deletion.** Products are soft-deleted (deactivated). A completed
+purchase stores a **snapshot** of what was sold (atom composition + price at the time) into
+an archive, so history/receipts/tax are independent of later catalog edits.
+
+## 8. Trusted platform signal
+
+The gate (§4) needs a **trusted, unforgeable** platform context on the server. The client is
+never the source of truth.
+
+- The platform is a **property of the session**, re-confirmed by a fresh signature on **every
+  cold start** — VK launch-params `sign` / TG `initData` (validator already exists at
+  `platform/telegram/internal/initdata`). VK/TG wrappers resend the signature on every open,
+  so this is not a one-time login.
+- `direct` is established by the fact of a web/native session's creation (no external
+  signer, and none needed — reaching vk/tg segments in a direct context still requires a
+  real attachment, §6).
+- The platform carries **kind** (`vk`/`telegram`/`direct`) **plus subtype**
+  (`ios`/`android`/`web`) — the subtype is mandatory (VK iOS is frozen).
+- The gateway resolves the session and passes `platform` to the backend (alongside the
+  existing `X-User-ID`).
+- **Fail-closed:** an untrusted/unconfirmed platform (a VK/TG session without a valid
+  cold-start signature; an old session with no recorded platform) denies spends/purchases
+  and applying any foreign origin — view only.
+
+## 9. Payment intake
+
+**Server callback only.** Chips are credited solely on a **verified** (signature/HMAC)
+provider callback — Robokassa webhook / TG `successful_payment` / VK callback. A client "I
+paid" is ignored.
+
+**Single writer.** One payments domain is the only writer of the ledger. Public webhooks
+(Robokassa/VK) terminate at the edge (Caddy/gateway) and proxy into payments; TG
+`successful_payment` reaches the bot, which forwards into payments. One place credits and
+dedupes.
+
+**Order-flow.** The server pre-creates an `order(pending)` with account / platform / pack /
+expected amount / origin. The `order_id` is threaded to the provider (Robokassa `InvId` / TG
+`invoice_payload` / VK `item` — confirm the exact VK field at integration). The callback
+matches by `order_id` (never by amount, so equal-amount collisions cannot happen), verifies
+the amount, credits, marks `paid`. **Idempotency:** dedup by `(provider, provider_payment_id)`.
+
+**Pending is invisible** to the user; it auto-expires on a timeout (~30 min, DB hygiene). A
+valid callback is **always** honoured, even on an expired order (`expired` ≠ cancellation —
+the money is real, the chips are owed). The user sees only successful purchases.
+
+**TG bot outbox.** `successful_payment` reaches the bot only (Bot API, not the Mini App), and
+the bot host is weak and can lose connectivity, so the bot is a durable link. Store-and-
+forward on **SQLite** on the bot's disk: receive → store → ack the Telegram update → forward
+to payments (idempotent, dedup by `telegram_payment_charge_id`) → ack → mark `forwarded`.
+Retries with backoff; re-drives undelivered on restart. At-least-once delivery + idempotent
+intake = credited exactly once.
+
+**Events.** The payments domain writes `payment_events` (succeeded / failed / refunded); a
+dispatcher fans out over channels — the live gRPC stream if the user is in-app, else the
+existing `botlink` push / email relay. "Payment failed" (an **active** provider decline, not
+an abandoned pending) is surfaced to the user; "payment succeeded" is a hook (email / bot
+message).
+
+**Refunds.** ToS is **non-refundable** — we do not offer refunds to the user. An admin may
+issue a **manual** refund (edge case: a user demands one shortly after paying / closes their
+account — tie into `accountdelete`, which already preserves messages). **External** refunds
+(chargeback / store decision / TG / VK) are honoured: the system takes the `refunded` event,
+**best-effort** revokes the benefit (never going negative; if chips were already spent, it
+records the loss + an abuse flag), and writes to the ledger. The ledger is **export-ready**
+for future tax reporting and Robokassa reconciliation (reconciliation itself is not built
+yet; the schema stays compatible).
+
+## 10. Ads
+
+**Launch scope: VK only** for video (rewarded payout in RUB, ОРД automatic, API ready).
+web/native/TG keep the existing house **text banner** only; video is deferred until a
+ruble-paying in-app network exists. The ad provider is behind an **abstraction** so a future
+network for other platforms slots in without rework. Crypto-payout networks (AdsGram/AdMob)
+are rejected — no legal ruble income for a self-employed (НПД) developer.
+
+**Rewarded** (voluntary video for chips) credits chips through payments on the network's
+**server verify callback** (client not believed, like a payment). On-launch anti-fraud is
+the provider's verify only (no own daily cap yet; the abstraction allows adding caps later).
+
+**Interstitial** (post-move fullscreen), configurable server-side values:
+
+- Global cooldown **per user, across all games**, default **5 min**.
+- **`vs_ai` — 30 min** (aligned with the hint cooldown, so it does not scare casual players).
+- Applying a **hint** triggers a post-move interstitial **independently** of the main
+  cooldown, with its own **1-min** cooldown.
+- Offline — banner only.
+- Respect VK's own frequency caps.
+
+**No ads offline** beyond the house banner. The `no-ads` benefit suppresses the banner via
+the existing `ads.Eligible` (`backend/internal/ads/ads.go`), which is extended to gate on
+the **origin benefit applicable in the current context** rather than one global flag.
+
+## 11. Admin, audit, reporting
+
+**Append-only ledger + materialized balance.** The operations ledger is **INSERT-only**
+(never UPDATE/DELETE — full audit). Segment balances `(account, source)` and benefits
+`(account, origin)` are a fast **materialized** cache, updated **in the same transaction** as
+the ledger write, and recomputable from the ledger for reconciliation.
+
+**Admin rewards.** An admin grants **concrete values only** (no-ads / hints) — **never
+chips** (a gifted currency balance = a store cash-desk bypass). The admin **picks the
+origin** at grant time (compliance is on them: `origin=vk` point-wise/low-volume = low risk,
+`origin=direct` = safe). A grant is a ledger transaction of type `admin_grant`, price 0
+chips — full audit of rewards.
+
+**Per-user financial report** in the admin console `/_gm` — segment balances, payments,
+spends, grants, refunds, full history — as an extension of the existing user card
+(`UserDetailView`, `handlers_admin_console.go`). Plus a ledger export.
+
+## 12. Taxes and compliance
+
+Receipts are automatic **through the provider**, and differ by rail:
+
+- **Robokassa** (direct) — self-employed НПД receipt on payment.
+- **VK** — VK processes Votes through the tax authority itself; nothing to do.
+- **TG Stars** — no tax side (for a RU self-employed, Stars are not legally withdrawable = not
+  НПД income; accepted, no receipt issued).
+
+**ОРД** (ad marking) for VK ads is handled on VK's side. (Not legal advice — the owner
+confirms the exact НПД scheme with a tax advisor.)
+
+## 13. Distribution (native Android)
+
+- **RuStore** — Robokassa/external gate allowed (0%); native = clean `direct` context.
+- **Google Play** — direct purchases are **hidden**; the Wallet shows a stub ("install the
+  RuStore build to make purchases"). Rewarded ads and spending already-earned chips still
+  work. Confirm Google's current in-app-currency rules before the GP release.
+
+## 14. Data model (schema `payments`)
+
+The payments domain lives in its **own schema `payments`** in the shared Postgres instance,
+with its own DB role (rights limited to `payments`) and a domain package behind a hard
+interface. There is **no cross-schema foreign key** to `backend.accounts` — an account id is a
+plain value here, kept consistent in code and joined to the tombstoned account /
+retained-identities dossier by the stable id. That keeps the chip↔benefit spend atomic
+**within `payments`** and the domain extractable into its own database. Durability is **PITR**
+(continuous WAL archive), independent of DB topology.
+
+Core tables (final names/columns fixed in `PLAN.md`):
+
+- **ledger** — append-only operations: fund / spend / `admin_grant` / refund; `(provider,
+  provider_payment_id)` unique for idempotency; export-ready.
+- **balances** — materialized `(account_id, source) → chips`.
+- **benefits** — materialized `(account_id, origin)` → no-ads `paid_until`/`forever` +
+  hints count.
+- **catalog** — atoms + products (soft-deletable), per-method prices, chip-purchase rates,
+  rewarded payout.
+- **orders** — pending purchases, `order_id`, expected amount, origin, status
+  (pending/paid/expired).
+- **payment_events** — succeeded/failed/refunded for the dispatcher.
+
+Legacy `accounts.hint_balance` and `accounts.paid_account` are **deprecated** in favour of the
+segmented model and dropped in a later **contract-phase** migration (expand-contract, after the
+currency core flips reads and Release 2 — image rollback stays DB-safe); neither was ever set in
+prod (no purchase flow existed), so legacy values are zeroed.
+
+## 15. Glossary
+
+- **Фишка / chip** — the in-game currency; uniform unit, segmented by `source`.
+- **source** — where chips were funded (`vk`/`telegram`/`direct`).
+- **origin** — where a value was bought; governs where the benefit applies.
+- **value / benefit** — what chips buy (no-ads, hints, tournament fee).
+- **gate** — the one-directional store-compliance rule (§4).
+- **ledger** — the append-only record of all money/value operations.
+- **rail** — a payment provider (Robokassa / VK Votes / TG Stars).

docs/PAYMENTS_ru.md

@@ -0,0 +1,343 @@
+# PAYMENTS — механики монетизации
+
+Русское зеркало [`PAYMENTS.md`](PAYMENTS.md) (английская версия — основная). Описывает
+домен монетизации: игровую валюту, кошельки, ценности, правила комплаенса сторов, приём
+платежей, рекламу, каталог, журнал операций и отчёты. Каждую правку `PAYMENTS.md` зеркалим
+сюда в том же PR (как `FUNCTIONAL.md`/`FUNCTIONAL_ru.md`).
+
+Читать перед любым изменением платёжного поведения. Технический план внедрения —
+[`../PLAN.md`](../PLAN.md).
+
+> Статус: спецификация утверждена; внедрение поэтапно (см. `PLAN.md`). В проде пока ничего
+> из этого нет.
+
+## 1. Обзор
+
+Игра зарабатывает двумя независимыми каналами:
+
+- **Покупки** игровой валюты **«Фишка»** за реальные деньги, затем трата Фишек на
+  **ценности** (бенефиты).
+- **Реклама** — ролик за награду пополняет Фишки; полноэкранный ролик и наш баннер
+  зарабатывают показами.
+
+Валюта **двухуровневая**:
+
+```
+деньги (Голоса VK / Stars TG / рубли через Robokassa)  ─┐
+                                                        ├─►  Фишки  ──►  ценности
+просмотр ролика за награду                             ─┘                (без рекламы,
+                                                                          подсказки,
+                                                                          турнирный взнос)
+```
+
+Фишки — единая единица витрины. Деньги и просмотры **пополняют** Фишки; Фишки **покупают**
+ценности. Прямой оплаты ценности деньгами нет — всегда через Фишки.
+
+## 2. Модель валюты
+
+**Одна Фишка равна одной Фишке везде** — единица единая. Разница между методами оплаты
+целиком в **курсе покупки**: пакет Фишек стоит *X* Голосов / *Y* Stars / *Z* рублей, и курс
+учитывает комиссию каждого стора. Цены ценностей фиксированы **в Фишках** и одинаковы для
+всех методов.
+
+Баланс Фишек **сегментирован по «источнику» (`source`)** — платформе, где Фишки пополнены:
+
+| `source`   | Чем пополняется                    |
+|------------|------------------------------------|
+| `vk`       | Покупка за Голоса VK, ролик за награду в VK |
+| `telegram` | Покупка за Stars TG                |
+| `direct`   | Покупка через Robokassa (web / native) |
+
+Один аккаунт держит все три сегмента одновременно: `баланс = (account_id, source)`, до трёх
+записей — запись материализуется лениво при первом пополнении сегмента, отсутствующий сегмент
+читается как ноль. Сегментация **не** по привязке (identity) — см. §6.
+
+Почему сегментировано, а не один общий баланс: правила сторов запрещают активировать
+ценность, оплаченную мимо их кассы. Фишки, пополненные внутри VK (Голоса), тратятся только
+в контексте VK; Stars — только внутри Telegram; Фишки от Robokassa (`direct`) — только вне
+сторов. См. §4.
+
+## 3. Три операции, которые нельзя путать
+
+Не смешивать — у них разные ключи:
+
+1. **Пополнить Фишки** — деньги/реклама → сегмент `source` Фишек, по **контексту
+   исполнения**.
+2. **Потратить Фишки = купить ценность** — сегмент → бенефит, по контексту с гейтом (§4).
+   Здесь бенефит **рождается** и помечается своим `origin`.
+3. **Применить бенефит** во времени (напр. «без рекламы до *T*») — по правилу `origin`
+   (§5).
+
+`source` (где пополнены Фишки) и `origin` (где куплена ценность) используют одно множество
+значений `{vk, telegram, direct}`, но значат разное. В вебе они расходятся: покупка в вебе
+может списать `vk`-Фишки (`source=vk`) в `direct`-покупку (`origin=direct`).
+
+## 4. Гейт комплаенса сторов
+
+Стена комплаенса **односторонняя**. Опасное направление — активация оплаченной снаружи
+ценности *внутри* обёртки стора — заблокировано; безопасное (бенефит стора действует
+наружу, в открытом вебе) — разрешено.
+
+**Контекст траты → какие сегменты/бенефиты доступны:**
+
+| Контекст исполнения  | Тратимые сегменты Фишек   | Приоритет траты    |
+|----------------------|---------------------------|--------------------|
+| Внутри VK (Android)  | `vk`                      | —                  |
+| Внутри VK (iOS)      | нет — заморожено (только просмотр) | —          |
+| Внутри Telegram      | `telegram`                | —                  |
+| Web / native (Direct)| `direct` + `vk` + `telegram` | direct → vk → tg |
+
+- Внутри VK/TG доступен только одноимённый сегмент; всё остальное (в первую очередь
+  `direct`) там невидимо как тратимое.
+- В вебе у стора нет юрисдикции, поэтому доступны все привязанные сегменты, списываются по
+  приоритету direct → vk → tg.
+- **VK iOS** заморожен для траты (Apple запрещает тратить виртуальную валюту на цифровые
+  товары мимо IAP внутри VK на iOS): баланс показывается числом, но покупка/трата
+  невозможны. Ранее купленный бенефит там всё равно *действует*.
+
+Аккаунт **единый** (привязки сливаются, один профиль/друзья/статистика). Гейт
+**логический**: в контексте VK/TG сервер активирует только одноимённый сегмент. Держится на
+**доверенном сигнале платформы** (§8) — клиенту не верим. Когда платформу нельзя доверенно
+установить, гейт **fail-closed**: траты/покупки запрещены, только просмотр.
+
+### Одностороннее применение бенефита
+
+Бенефит несёт `origin` = **контекст покупки** (не «чем оплачено»). Покупка в вебе за
+`vk`-Фишки всё равно даёт `origin=direct`.
+
+| `origin`         | Где действует бенефит                              |
+|------------------|----------------------------------------------------|
+| `vk` / `telegram`| **Везде** — внутри своего стора *и* наружу в web/native |
+| `direct`         | **Только** web/native — никогда внутри VK/TG (= бан) |
+
+Перед тратой в вебе `vk`/`telegram`-Фишек интерфейс **предупреждает**, что ценность будет
+доступна только здесь (web/native) из-за ограничений VK/TG.
+
+## 5. Ценности
+
+Три разные сущности, не смешивать:
+
+- **Фишки** — валюта. Сегмент по `source`.
+- **Подсказки** — расходник, покупается за Фишки. Сегмент по `origin`. Тратятся по одной в
+  онлайн-играх; в `vs_ai` подсказки бесплатны/безлимитны (30-мин кулдаун, не в счёт).
+  Подсказка в игре списывается из `origin`, применимого в текущем контексте (то же
+  одностороннее послабление).
+- **Без рекламы** — срок-бенефит, покупается за Фишки. Сегмент по `origin`.
+
+**Складывание «без рекламы».** Покупка срока продлевает `paid_until[origin] += срок` от
+`max(сейчас, текущий конец)` — остаток не теряется («сроки плюсуются»). **Навсегда** —
+отдельный вечный флаг, перекрывает сроки. «Реклама выключена в контексте *P*» ⇔ есть
+применимый в *P* `origin` с `paid_until > сейчас` (в вебе берём максимум по direct/vk/tg; в
+VK только vk; в TG только tg).
+
+**Что гасит «без рекламы»:** верхний баннер **и** полноэкранный ролик после хода.
+Добровольный **ролик за награду** (за Фишки) не гасится — это выбор пользователя.
+
+**Турнирный взнос** — будущий тип ценности; атом заложен, механика позже.
+
+## 6. Жизненный цикл кошелька
+
+**Правило доступности сегмента.** Сегмент тратим ⇔ на аккаунте есть привязка этого
+`source` (для `direct` — устойчивая привязка/email). Отсюда unlink/мерж выводятся
+естественно.
+
+**Отвязка (vk/tg).** Разрешена даже при ненулевом балансе/активном бенефите. Сегмент не
+сжигается — он **засыпает** (нет привязки ⇒ недоступен в VK *и*, без привязки, недоступен
+как подтянутый веб-сегмент); повторная привязка будит. Перед отвязкой предупреждение
+(«N Фишек станут недоступны до повторной привязки»). Последнюю привязку отвязать нельзя
+(существующий `ErrLastIdentity`).
+
+**Мерж.** Сегменты и бенефиты сливаются **по origin**: одноимённые складываются (Фишки
+суммируются, сроки бенефита продлеваются по origin), разные сосуществуют. Это расширяет
+текущий мерж аккаунтов (`hint_balance +=`, `paid_account OR=`), так что origin сохраняется и
+ничего не протекает между платформами.
+
+**Гость.** У гостевого аккаунта **вообще нет кошелька** — раздел «Кошелёк» скрыт, покупок
+нет, баланса нет, by design. Балансы — только у durable-аккаунтов. Поэтому чистильщик
+гостей удаляет их свободно (денег там быть не может). В `direct` email обязателен **перед
+первой покупкой** как якорь восстановления (в VK/TG якорь — сама vk/tg-привязка);
+переиспользуем существующий флоу email (запрос кода → подтверждение → снятие флага гостя →
+durable).
+
+## 7. Каталог и цены
+
+Каталог **конфигурируемый** — продукты, цены, курсы покупки и награда за ролик живут в базе
+и правятся в админке, без релиза.
+
+- **Базовые ценности (атомы):** Фишки, подсказки, дни без рекламы, участие в турнире.
+- **Продукт = набор атомов + цена.** Продаётся по одной или комбо (напр. «250 подсказок +
+  30 дней без рекламы»).
+- **Пакет Фишек** (пополняет Фишки) — цена **per-метод** (мультивалютная Голоса/Stars/руб)
+  одним продуктом.
+- **Ценность** (за Фишки) — цена **в Фишках** (единая для всех методов).
+
+**Деактивация, не удаление.** Продукты деактивируются (soft-delete). Состоявшаяся покупка
+хранит **снимок** проданного (состав атомов + цена на момент) в архиве, чтобы
+история/чеки/налоги не зависели от последующих правок каталога.
+
+## 8. Доверенный сигнал платформы
+
+Гейту (§4) нужен **доверенный, неподделываемый** контекст платформы на сервере. Клиент —
+никогда не источник правды.
+
+- Платформа — **свойство сессии**, переподтверждается свежей подписью на **каждом холодном
+  старте** — VK launch-params `sign` / TG `initData` (валидатор уже есть в
+  `platform/telegram/internal/initdata`). Обёртки VK/TG шлют подпись при каждом открытии,
+  так что это не одноразовый вход.
+- `direct` устанавливается самим фактом создания веб/native-сессии (внешней подписи нет и
+  не нужно — доступ к vk/tg-сегментам в direct-контексте всё равно требует реальной
+  привязки, §6).
+- Платформа несёт **kind** (`vk`/`telegram`/`direct`) **плюс подтип**
+  (`ios`/`android`/`web`) — подтип обязателен (VK iOS заморожен).
+- Гейтвей резолвит сессию и передаёт `platform` в бэкенд (рядом с существующим
+  `X-User-ID`).
+- **Fail-closed:** недоверенная/неподтверждённая платформа (VK/TG-сессия без валидной
+  подписи на холодном старте; старая сессия без записанной платформы) запрещает
+  траты/покупки и применение любого чужого origin — только просмотр.
+
+## 9. Приём платежей
+
+**Только серверный колбэк провайдера.** Фишки начисляются лишь по **проверенному**
+(подпись/HMAC) серверному колбэку — Robokassa webhook / TG `successful_payment` / VK
+callback. Клиентское «я оплатил» игнорируется.
+
+**Единственный писатель.** Один платёжный домен — единственный, кто пишет в журнал операций.
+Публичные вебхуки (Robokassa/VK) терминируются на краю (Caddy/gateway) и проксируются в
+платёжный домен; TG `successful_payment` приходит боту, тот форвардит в платёжный домен.
+Одно место начисляет и защищает от повторов.
+
+**Флоу заказа.** Сервер заранее создаёт `order(pending)` с account / платформой / пакетом /
+ожидаемой суммой / origin. `order_id` прокидывается провайдеру (Robokassa `InvId` / TG
+`invoice_payload` / VK `item` — точную форму VK уточнить при интеграции). Колбэк матчится по
+`order_id` (никогда по сумме, поэтому коллизии одинаковых сумм невозможны), сверяет сумму,
+начисляет, помечает `paid`. **Защита от повторов:** дедуп по `(провайдер,
+provider_payment_id)`.
+
+**Pending невидим** пользователю; авто-истекает по таймауту (~30 мин, гигиена базы).
+Валидный колбэк исполняется **всегда**, даже на истёкшем заказе (`expired` ≠ отмена —
+деньги реальны, Фишки должны быть выданы). Пользователь видит только успешные покупки.
+
+**Outbox TG-бота.** `successful_payment` приходит только боту (Bot API, не Mini App), а
+хост бота слабый и может терять связь, поэтому бот — durable-звено. Store-and-forward на
+**SQLite** на диске бота: получил → сохранил → подтвердил апдейт Telegram → форвардит в
+платёжный домен (идемпотентно, дедуп по `telegram_payment_charge_id`) → ack → пометил
+`forwarded`. Ретраи с backoff; дореталивает недоставленное при рестарте. Доставка
+at-least-once + идемпотентный приём = начисление ровно один раз.
+
+**События.** Платёжный домен пишет `payment_events` (succeeded / failed / refunded);
+диспетчер рассылает по каналам — live gRPC-стрим, если пользователь в аппе, иначе
+существующий пуш `botlink` / email. «Оплата не прошла» (**активный** отказ провайдера, не
+брошенный pending) доводится до пользователя; «оплата прошла» — хук (письмо / сообщение в
+бота).
+
+**Возвраты.** ToS — **невозвратно**, пользователю возврат не предлагаем. Админ может сделать
+**ручной** возврат (крайний случай: пользователь требует вскоре после оплаты / закрывает
+аккаунт — связано с `accountdelete`, где уже сохраняются сообщения). **Внешние** возвраты
+(чарджбек / решение стора / TG / VK) обрабатываются: система принимает событие `refunded`,
+**по возможности** отзывает бенефит (в минус не уходим; если Фишки уже потрачены —
+фиксирует убыток + флаг защиты от злоупотреблений), пишет в журнал. Журнал операций
+**спроектирован экспортопригодным** для будущей налоговой отчётности и сверки с Robokassa
+(саму сверку пока не строим; схема остаётся совместимой).
+
+## 10. Реклама
+
+**Охват на старте: только VK** для видео (награда в рублях, ОРД автоматом, API готов).
+web/native/TG держат только существующий наш **текст-баннер**; видео отложено до появления
+рублёвой in-app сети. Рекламный провайдер за **абстракцией**, чтобы будущая сеть для других
+платформ встроилась без переделки. Крипто-сети (AdsGram/AdMob) отвергнуты — нет легального
+рублёвого дохода самозанятому (НПД).
+
+**Ролик за награду** (добровольное видео за Фишки) начисляет Фишки через платёжный домен по
+**серверному verify-колбэку** сети (клиенту не верим, как платежу). Антифрод на старте — только
+verify провайдера (своего дневного потолка пока нет; абстракция позволит добавить лимиты
+позже).
+
+**Полноэкранный ролик** (после хода), конфигурируемые серверные значения:
+
+- Глобальный кулдаун **на пользователя, сквозь все партии**, дефолт **5 мин**.
+- **`vs_ai` — 30 мин** (соосно кулдауну подсказок, чтобы не отпугивать казуалов).
+- Применение **подсказки** триггерит ролик после хода **независимо** от основного кулдауна,
+  со своим кулдауном **1 мин**.
+- Оффлайн — только баннер.
+- Уважать собственные лимиты частоты VK.
+
+**Оффлайн без рекламы**, кроме нашего баннера. Бенефит `без рекламы` гасит баннер через
+существующий `ads.Eligible` (`backend/internal/ads/ads.go`), который расширяется до гейта по
+**origin-бенефиту, применимому в текущем контексте**, а не по одному глобальному флагу.
+
+## 11. Админ, аудит, отчётность
+
+**Неизменяемый журнал операций + материализованный баланс.** Журнал операций **только на
+INSERT** (никогда UPDATE/DELETE — полный аудит). Балансы сегментов `(account, source)` и
+бенефиты `(account, origin)` — быстрый **материализованный** кэш, обновляется **в той же
+транзакции**, что и запись журнала, и пересчитывается из журнала для сверки.
+
+**Награждение админом.** Админ начисляет **только конкретные ценности** (без рекламы /
+подсказки) — **никогда не Фишки** (подаренный баланс валюты = обход кассы стора). Админ
+**выбирает origin** при выдаче (ответственность за комплаенс на нём: `origin=vk`
+точечно/малый объём = низкий риск, `origin=direct` = безопасно). Грант — транзакция журнала
+типа `admin_grant`, цена 0 Фишек — полный аудит наград.
+
+**Финансовый отчёт по пользователю** в админке `/_gm` — балансы сегментов, платежи, траты,
+гранты, возвраты, полная история — расширение существующей карточки (`UserDetailView`,
+`handlers_admin_console.go`). Плюс экспорт журнала.
+
+## 12. Налоги и комплаенс
+
+Чеки формируются автоматически **на стороне провайдера** и отличаются по каналу:
+
+- **Robokassa** (direct) — чек НПД самозанятого при оплате.
+- **VK** — VK сам процессит Голоса через налоговую; делать нечего.
+- **TG Stars** — налоговой стороны нет (для РФ-самозанятого Stars легально невыводимы = не
+  доход НПД; принимаем, чек не формируем).
+
+**ОРД** (маркировка рекламы) по VK-рекламе — на стороне VK. (Не юридическая консультация —
+владелец сверяет точную схему НПД с налоговым консультантом.)
+
+## 13. Дистрибуция (native Android)
+
+- **RuStore** — Robokassa/внешний гейт разрешён (0%); native = чистый контекст `direct`.
+- **Google Play** — direct-покупки **скрыты**; «Кошелёк» показывает заглушку («установите
+  версию из RuStore для покупок»). Ролик за награду и трата уже накопленных Фишек работают.
+  Перед GP-релизом свериться с актуальными правилами Google по внутренней валюте.
+
+## 14. Модель данных (схема `payments`)
+
+Платёжный домен живёт в **своей схеме `payments`** в общем инстансе Postgres, со своим
+DB-ролём (права только на `payments`) и доменным пакетом за жёстким интерфейсом.
+**Cross-schema внешнего ключа** к `backend.accounts` **нет** — идентификатор аккаунта здесь
+обычное значение, согласуемое в коде и связываемое с tombstone-аккаунтом / досье
+retained-identities по стабильному id. Это держит трату «Фишки↔бенефит» атомарной **внутри
+`payments`** и делает домен извлекаемым в свою базу. Сохранность — **PITR** (непрерывный
+WAL-архив), независимо от топологии базы.
+
+Основные таблицы (финальные имена/колонки — в `PLAN.md`):
+
+- **журнал операций (ledger)** — append-only операции: пополнение / трата / `admin_grant` /
+  возврат; `(провайдер, provider_payment_id)` уникален для защиты от повторов;
+  экспортопригоден.
+- **балансы** — материализованные `(account_id, source) → Фишки`.
+- **бенефиты** — материализованные `(account_id, origin)` → «без рекламы»
+  `paid_until`/`forever` + счётчик подсказок.
+- **каталог** — атомы + продукты (деактивируемые), цены per-метод, курсы покупки Фишек,
+  награда за ролик.
+- **заказы (orders)** — pending-покупки, `order_id`, ожидаемая сумма, origin, статус
+  (pending/paid/expired).
+- **payment_events** — succeeded/failed/refunded для диспетчера.
+
+Legacy `accounts.hint_balance` и `accounts.paid_account` **устаревают** в пользу
+сегментированной модели и удаляются в отдельной **contract-миграции** (expand-contract, после
+того как валютное ядро переключит чтения, и после Release 2 — откат образа остаётся безопасным
+для БД); ни то, ни другое в проде никогда не выставлялось (потока покупки не было), поэтому
+legacy-значения обнуляются.
+
+## 15. Словарь
+
+- **Фишка** — игровая валюта; единая единица, сегментирована по `source`.
+- **source (источник)** — где пополнены Фишки (`vk`/`telegram`/`direct`).
+- **origin (происхождение)** — где куплена ценность; определяет, где действует бенефит.
+- **ценность / бенефит** — то, что покупается за Фишки (без рекламы, подсказки, турнирный
+  взнос).
+- **гейт** — одностороннее правило комплаенса сторов (§4).
+- **журнал операций (ledger)** — неизменяемая запись всех операций с деньгами/ценностями.
+- **платёжный канал / рельса** — платёжный провайдер (Robokassa / Голоса VK / Stars TG).

docs/TESTING.md

@@ -20,7 +20,18 @@ tests or touching CI.
   derivation and the GCG share/copy/download choice, plus Playwright specs against the
   mock for the friends screen (code issue/redeem, accept a request), the lobby
   invitations section, the stats screen, profile editing, and the export chooser's
-  finished-only visibility + its signed-URL download flow (route-intercepted).
+  finished-only visibility + its signed-URL download flow (route-intercepted). The
+  **offline mode** spec (`e2e/offline.spec.ts`) plays a full device-local `vs_ai` game
+  end-to-end: it forces the installed-PWA display mode, enters offline through the
+  Settings toggle (whose readiness check fetches the enabled variants' dawgs), then creates
+  and plays a local game with a **pinned bag seed** (`window.__mock.setLocalSeed`, so the
+  rack is deterministic and the human can tap out a precomputed opening), asserting the
+  robot's real reply and the IndexedDB replay after a reload. A local game needs a real
+  dictionary, so the mock's `fetchDict` serves the per-variant dawgs from the preview
+  build's `/e2edict/`, copied in by `scripts/e2e-dict.mjs` from `E2E_DICT_DIR` — the `ui`
+  CI job fetches the `scrabble-dictionary` release like the Go jobs; locally it defaults to
+  the sibling `scrabble-solver/dawg`. These dawgs are never committed and never enter the
+  production build.
 - **Render sidecar** — `renderer/` (Node + skia-canvas executing the shared
   `ui/src/lib/gameimage.ts`) carries a `node --test` smoke: the committed fixture (a
   real self-played 35-move game) must rasterize to a plausible PNG

gateway/README.md

@@ -8,9 +8,10 @@ backend over REST/JSON, and bridges the backend's gRPC push stream to each
 client's in-app live channel. It **embeds the static UI build** (`go:embed`, baked
 in by the gateway image's node stage) and serves a **landing page** at `/` and the game
 **SPA** at `/app/` (web), `/telegram/` (the Telegram Mini App) and `/vk/` (the VK Mini App) — the single-origin model.
-The web SPA is an installable **PWA**: it serves `manifest.webmanifest` (with the `.webmanifest`
-MIME type registered in-process — the distroless image has no `/etc/mime.types`) and the
-install-only `sw.js`, both shipped unhashed from `ui/public/`.
+The web SPA is an installable **PWA**: it serves `manifest.webmanifest` (unhashed from `ui/public/`,
+with the `.webmanifest` MIME type registered in-process — the distroless image has no
+`/etc/mime.types`) and the app-shell `sw.js` (built from `ui/src/sw.ts` by vite-plugin-pwa, which
+precaches the shell + assets so an installed PWA cold-launches offline).
 Hash-named `/assets/*` are served `immutable`; the HTML shells are `no-cache`. It can also serve the
 backend's admin console at `/_gm` behind HTTP Basic-Auth for a local non-caddy run;
 in the deployed contour the front caddy owns `/_gm` (see

gateway/internal/backendclient/api.go

@@ -42,6 +42,15 @@ type ProfileResp struct {
 	Email          string `json:"email"`
 	TelegramLinked bool   `json:"telegram_linked"`
 	VkLinked       bool   `json:"vk_linked"`
+	// DictVersions is the current dictionary version per game variant, forwarded verbatim
+	// into the Profile payload so an offline-capable client preloads the matching dawg.
+	DictVersions []DictVersion `json:"dict_versions,omitempty"`
+}
+
+// DictVersion pairs a game variant's stable label with its current dictionary version.
+type DictVersion struct {
+	Variant string `json:"variant"`
+	Version string `json:"version"`
 }
 
 // BannerResp is the advertising-banner block of an eligible viewer's profile: the
@@ -172,13 +181,14 @@ type AlphabetEntryJSON struct {
 // StateResp is a player's view of a game. Rack carries wire alphabet indices;
 // Alphabet is present only when the request asked for it.
 type StateResp struct {
-	Game           GameResp            `json:"game"`
-	Seat           int                 `json:"seat"`
-	Rack           []int               `json:"rack"`
-	BagLen         int                 `json:"bag_len"`
-	HintsRemaining int                 `json:"hints_remaining"`
-	WalletBalance  int                 `json:"wallet_balance"`
-	Alphabet       []AlphabetEntryJSON `json:"alphabet,omitempty"`
+	Game                  GameResp            `json:"game"`
+	Seat                  int                 `json:"seat"`
+	Rack                  []int               `json:"rack"`
+	BagLen                int                 `json:"bag_len"`
+	HintsRemaining        int                 `json:"hints_remaining"`
+	WalletBalance         int                 `json:"wallet_balance"`
+	HintUnlockLeftSeconds int                 `json:"hint_unlock_left_seconds"`
+	Alphabet              []AlphabetEntryJSON `json:"alphabet,omitempty"`
 }
 
 // MatchResp reports an auto-match outcome.

gateway/internal/transcode/encode.go

@@ -95,6 +95,7 @@ func encodeProfile(p backendclient.ProfileResp) []byte {
 		banner = encodeBanner(b, *p.Banner)
 	}
 	prefs := buildStringVector(b, p.VariantPreferences, fb.ProfileStartVariantPreferencesVector)
+	dictVersions := encodeDictVersions(b, p.DictVersions)
 	fb.ProfileStart(b)
 	fb.ProfileAddUserId(b, uid)
 	fb.ProfileAddDisplayName(b, name)
@@ -111,6 +112,9 @@ func encodeProfile(p backendclient.ProfileResp) []byte {
 	fb.ProfileAddEmail(b, email)
 	fb.ProfileAddTelegramLinked(b, p.TelegramLinked)
 	fb.ProfileAddVkLinked(b, p.VkLinked)
+	if dictVersions != 0 {
+		fb.ProfileAddDictVersions(b, dictVersions)
+	}
 	if p.Banner != nil {
 		fb.ProfileAddBanner(b, banner)
 	}
@@ -118,6 +122,31 @@ func encodeProfile(p backendclient.ProfileResp) []byte {
 	return b.FinishedBytes()
 }
 
+// encodeDictVersions builds the Profile's dict_versions vector — one DictVersion table per
+// variant/version pair — and returns its offset, or 0 when there are none (the field is then
+// omitted). Every child table and its strings are created before the vector is opened, per the
+// FlatBuffers rule against nesting a table under one still being built; the caller invokes it
+// before ProfileStart for the same reason.
+func encodeDictVersions(b *flatbuffers.Builder, dvs []backendclient.DictVersion) flatbuffers.UOffsetT {
+	if len(dvs) == 0 {
+		return 0
+	}
+	offsets := make([]flatbuffers.UOffsetT, len(dvs))
+	for i, dv := range dvs {
+		variant := b.CreateString(dv.Variant)
+		version := b.CreateString(dv.Version)
+		fb.DictVersionStart(b)
+		fb.DictVersionAddVariant(b, variant)
+		fb.DictVersionAddVersion(b, version)
+		offsets[i] = fb.DictVersionEnd(b)
+	}
+	fb.ProfileStartDictVersionsVector(b, len(offsets))
+	for i := len(offsets) - 1; i >= 0; i-- {
+		b.PrependUOffsetT(offsets[i])
+	}
+	return b.EndVector(len(offsets))
+}
+
 // optString creates a FlatBuffers string for a non-empty value, or 0 to omit the
 // optional field (the client then reads it as absent).
 func optString(b *flatbuffers.Builder, s string) flatbuffers.UOffsetT {
@@ -270,13 +299,14 @@ func toWireState(s backendclient.StateResp) wire.StateView {
 		alphabet[i] = wire.AlphabetEntry{Index: e.Index, Letter: e.Letter, Value: e.Value}
 	}
 	return wire.StateView{
-		Game:           toWireGame(s.Game),
-		Seat:           s.Seat,
-		Rack:           s.Rack,
-		BagLen:         s.BagLen,
-		HintsRemaining: s.HintsRemaining,
-		WalletBalance:  s.WalletBalance,
-		Alphabet:       alphabet,
+		Game:                  toWireGame(s.Game),
+		Seat:                  s.Seat,
+		Rack:                  s.Rack,
+		BagLen:                s.BagLen,
+		HintsRemaining:        s.HintsRemaining,
+		WalletBalance:         s.WalletBalance,
+		HintUnlockLeftSeconds: s.HintUnlockLeftSeconds,
+		Alphabet:              alphabet,
 	}
 }
 

gateway/internal/transcode/transcode_test.go

@@ -59,7 +59,7 @@ func TestGameStateRoundTripForwardsUserID(t *testing.T) {
 		if r.URL.Path != "/api/v1/user/games/g-1/state" {
 			t.Errorf("unexpected path %q", r.URL.Path)
 		}
-		_, _ = w.Write([]byte(`{"game":{"id":"g-1","variant":"scrabble_en","status":"active","players":2,"to_move":1,"seats":[{"seat":0,"account_id":"u-7","score":5}]},"seat":0,"rack":[0,1],"bag_len":80,"hints_remaining":4,"wallet_balance":3}`))
+		_, _ = w.Write([]byte(`{"game":{"id":"g-1","variant":"scrabble_en","status":"active","players":2,"to_move":1,"seats":[{"seat":0,"account_id":"u-7","score":5}]},"seat":0,"rack":[0,1],"bag_len":80,"hints_remaining":4,"wallet_balance":3,"hint_unlock_left_seconds":1200}`))
 	})
 	defer cleanup()
 
@@ -77,8 +77,8 @@ func TestGameStateRoundTripForwardsUserID(t *testing.T) {
 		t.Fatalf("handler: %v", err)
 	}
 	st := fb.GetRootAsStateView(payload, 0)
-	if st.BagLen() != 80 || st.RackLength() != 2 || st.HintsRemaining() != 4 || st.WalletBalance() != 3 {
-		t.Fatalf("state decoded wrong: bag=%d rack=%d hints=%d wallet=%d", st.BagLen(), st.RackLength(), st.HintsRemaining(), st.WalletBalance())
+	if st.BagLen() != 80 || st.RackLength() != 2 || st.HintsRemaining() != 4 || st.WalletBalance() != 3 || st.HintUnlockLeftSeconds() != 1200 {
+		t.Fatalf("state decoded wrong: bag=%d rack=%d hints=%d wallet=%d unlockLeft=%d", st.BagLen(), st.RackLength(), st.HintsRemaining(), st.WalletBalance(), st.HintUnlockLeftSeconds())
 	}
 	game := st.Game(nil)
 	if game == nil || string(game.Id()) != "g-1" || string(game.Variant()) != "scrabble_en" || game.ToMove() != 1 {

gateway/internal/webui/webui.go

@@ -71,6 +71,11 @@ func handlerFor(content fs.FS, stripPrefix, indexName string) http.Handler {
 		// app (notably a relaunched Telegram Mini App) is a cache hit, not a re-download.
 		if strings.HasPrefix(name, "assets/") {
 			w.Header().Set("Cache-Control", "public, max-age=31536000, immutable")
+		} else if name == "sw.js" {
+			// The service worker must be revalidated on every load so a new deploy's worker (and its
+			// fresh precache manifest) is picked up promptly; a cached sw.js would strand clients on
+			// the old build. The worker's network-first navigation then serves the fresh shell online.
+			w.Header().Set("Cache-Control", "no-cache")
 		}
 		files.ServeHTTP(w, r)
 	})

gateway/internal/webui/webui_test.go

@@ -94,6 +94,10 @@ func TestHandlerServesServiceWorkerAsJavaScript(t *testing.T) {
 	if ct := resp.Header.Get("Content-Type"); !strings.HasPrefix(ct, "text/javascript") {
 		t.Errorf("Content-Type = %q, want text/javascript", ct)
 	}
+	// Revalidated on every load so a new deploy's worker (and its fresh precache) is picked up.
+	if cc := resp.Header.Get("Cache-Control"); cc != "no-cache" {
+		t.Errorf("sw.js Cache-Control = %q, want no-cache", cc)
+	}
 }
 
 // TestHandlerFallsBackToShellForUnknownManifestPath guards the trap: a manifest/sw path NOT emitted

pkg/fbs/scrabble.fbs

@@ -223,6 +223,13 @@ table BannerInfo {
 // suppresses out-of-app platform push, leaving only the in-app live stream. banner
 // carries the advertising-banner block for an eligible viewer, absent otherwise
 // (all added trailing — backward-compatible).
+// DictVersion is one variant's current dictionary version, carried on the profile so an offline
+// client learns it from an existing cold-start request (no extra call for a rarely-used feature).
+table DictVersion {
+  variant:string;
+  version:string;
+}
+
 table Profile {
   user_id:string;
   display_name:string;
@@ -245,6 +252,10 @@ table Profile {
   email:string;
   telegram_linked:bool;
   vk_linked:bool;
+  // dict_versions carries each variant's current dictionary version so an offline client can
+  // preload the right dictionary and pin a new local game without a separate request (added
+  // trailing — backward-compatible).
+  dict_versions:[DictVersion];
 }
 
 // BlockStatus reports the caller's current manual block. The UI fetches it after any operation
@@ -305,6 +316,13 @@ table StateView {
   // the wallet is a single global figure the client keeps live across games (added trailing —
   // backward-compatible).
   wallet_balance:int;
+  // hint_unlock_left_seconds is, for a vs_ai game, how many seconds until the idle hint unlocks
+  // (the robot's last move plus the idle window, computed from the SERVER clock online / the device
+  // clock offline, capped at the window and floored at 0); 0 for a human's first move (no robot move
+  // yet) or a non-vs_ai game. The client anchors a MONOTONIC countdown (performance.now()) to it, so a
+  // client clock change cannot skew it — see lib/hints. Seconds granularity is enough; sent trailing
+  // (additive, backward-compatible).
+  hint_unlock_left_seconds:int;
 }
 
 // GameActionRequest carries just a game id (pass / resign / hint / history).

pkg/fbs/scrabblefb/DictVersion.go

@@ -0,0 +1,71 @@
+// Code generated by the FlatBuffers compiler. DO NOT EDIT.
+
+package scrabblefb
+
+import (
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type DictVersion struct {
+	_tab flatbuffers.Table
+}
+
+func GetRootAsDictVersion(buf []byte, offset flatbuffers.UOffsetT) *DictVersion {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &DictVersion{}
+	x.Init(buf, n+offset)
+	return x
+}
+
+func FinishDictVersionBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.Finish(offset)
+}
+
+func GetSizePrefixedRootAsDictVersion(buf []byte, offset flatbuffers.UOffsetT) *DictVersion {
+	n := flatbuffers.GetUOffsetT(buf[offset+flatbuffers.SizeUint32:])
+	x := &DictVersion{}
+	x.Init(buf, n+offset+flatbuffers.SizeUint32)
+	return x
+}
+
+func FinishSizePrefixedDictVersionBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.FinishSizePrefixed(offset)
+}
+
+func (rcv *DictVersion) Init(buf []byte, i flatbuffers.UOffsetT) {
+	rcv._tab.Bytes = buf
+	rcv._tab.Pos = i
+}
+
+func (rcv *DictVersion) Table() flatbuffers.Table {
+	return rcv._tab
+}
+
+func (rcv *DictVersion) Variant() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(4))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *DictVersion) Version() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(6))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func DictVersionStart(builder *flatbuffers.Builder) {
+	builder.StartObject(2)
+}
+func DictVersionAddVariant(builder *flatbuffers.Builder, variant flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(variant), 0)
+}
+func DictVersionAddVersion(builder *flatbuffers.Builder, version flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(1, flatbuffers.UOffsetT(version), 0)
+}
+func DictVersionEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
+	return builder.EndObject()
+}

pkg/fbs/scrabblefb/Profile.go

@@ -211,8 +211,28 @@ func (rcv *Profile) MutateVkLinked(n bool) bool {
 	return rcv._tab.MutateBoolSlot(34, n)
 }
 
+func (rcv *Profile) DictVersions(obj *DictVersion, j int) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(36))
+	if o != 0 {
+		x := rcv._tab.Vector(o)
+		x += flatbuffers.UOffsetT(j) * 4
+		x = rcv._tab.Indirect(x)
+		obj.Init(rcv._tab.Bytes, x)
+		return true
+	}
+	return false
+}
+
+func (rcv *Profile) DictVersionsLength() int {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(36))
+	if o != 0 {
+		return rcv._tab.VectorLen(o)
+	}
+	return 0
+}
+
 func ProfileStart(builder *flatbuffers.Builder) {
-	builder.StartObject(16)
+	builder.StartObject(17)
 }
 func ProfileAddUserId(builder *flatbuffers.Builder, userId flatbuffers.UOffsetT) {
 	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(userId), 0)
@@ -265,6 +285,12 @@ func ProfileAddTelegramLinked(builder *flatbuffers.Builder, telegramLinked bool)
 func ProfileAddVkLinked(builder *flatbuffers.Builder, vkLinked bool) {
 	builder.PrependBoolSlot(15, vkLinked, false)
 }
+func ProfileAddDictVersions(builder *flatbuffers.Builder, dictVersions flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(16, flatbuffers.UOffsetT(dictVersions), 0)
+}
+func ProfileStartDictVersionsVector(builder *flatbuffers.Builder, numElems int) flatbuffers.UOffsetT {
+	return builder.StartVector(4, numElems, 4)
+}
 func ProfileEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
 	return builder.EndObject()
 }

pkg/fbs/scrabblefb/StateView.go

@@ -156,8 +156,20 @@ func (rcv *StateView) MutateWalletBalance(n int32) bool {
 	return rcv._tab.MutateInt32Slot(16, n)
 }
 
+func (rcv *StateView) HintUnlockLeftSeconds() int32 {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(18))
+	if o != 0 {
+		return rcv._tab.GetInt32(o + rcv._tab.Pos)
+	}
+	return 0
+}
+
+func (rcv *StateView) MutateHintUnlockLeftSeconds(n int32) bool {
+	return rcv._tab.MutateInt32Slot(18, n)
+}
+
 func StateViewStart(builder *flatbuffers.Builder) {
-	builder.StartObject(7)
+	builder.StartObject(8)
 }
 func StateViewAddGame(builder *flatbuffers.Builder, game flatbuffers.UOffsetT) {
 	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(game), 0)
@@ -186,6 +198,9 @@ func StateViewStartAlphabetVector(builder *flatbuffers.Builder, numElems int) fl
 func StateViewAddWalletBalance(builder *flatbuffers.Builder, walletBalance int32) {
 	builder.PrependInt32Slot(6, walletBalance, 0)
 }
+func StateViewAddHintUnlockLeftSeconds(builder *flatbuffers.Builder, hintUnlockLeftSeconds int32) {
+	builder.PrependInt32Slot(7, hintUnlockLeftSeconds, 0)
+}
 func StateViewEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
 	return builder.EndObject()
 }

pkg/wire/build.go

@@ -87,13 +87,14 @@ type AlphabetEntry struct {
 // (wire alphabet indices), bag size and hint budget. Alphabet is set only when the
 // recipient may not have cached the variant's display table yet.
 type StateView struct {
-	Game           GameView
-	Seat           int
-	Rack           []int
-	BagLen         int
-	HintsRemaining int
-	WalletBalance  int
-	Alphabet       []AlphabetEntry
+	Game                  GameView
+	Seat                  int
+	Rack                  []int
+	BagLen                int
+	HintsRemaining        int
+	WalletBalance         int
+	HintUnlockLeftSeconds int
+	Alphabet              []AlphabetEntry
 }
 
 // AccountRef is a referenced account with its display name resolved.
@@ -256,6 +257,7 @@ func BuildStateView(b *flatbuffers.Builder, s StateView) flatbuffers.UOffsetT {
 	fb.StateViewAddBagLen(b, int32(s.BagLen))
 	fb.StateViewAddHintsRemaining(b, int32(s.HintsRemaining))
 	fb.StateViewAddWalletBalance(b, int32(s.WalletBalance))
+	fb.StateViewAddHintUnlockLeftSeconds(b, int32(s.HintUnlockLeftSeconds))
 	if hasAlphabet {
 		fb.StateViewAddAlphabet(b, alphabet)
 	}

ui/e2e/hotseat.spec.ts

@@ -0,0 +1,126 @@
+import { test, expect, type Page } from './fixtures';
+
+// Offline pass-and-play (hotseat) is offered only in offline mode, which is gated to an installed
+// standalone PWA with a confirmed email. The mock account has an email; force standalone so the
+// Settings offline toggle shows.
+async function forceStandalone(page: Page): Promise<void> {
+  await page.addInitScript(() => {
+    const orig = window.matchMedia.bind(window);
+    window.matchMedia = (q: string) =>
+      (q.includes('display-mode: standalone')
+        ? { matches: true, media: q, onchange: null, addEventListener() {}, removeEventListener() {}, addListener() {}, removeListener() {}, dispatchEvent: () => false }
+        : orig(q)) as MediaQueryList;
+  });
+}
+
+async function enterLobby(page: Page): Promise<void> {
+  await page.getByRole('button', { name: /guest|гост/i }).first().click();
+  await expect(page.locator('button.tab').nth(2)).toBeVisible();
+}
+
+async function goOffline(page: Page): Promise<void> {
+  await page.locator('button.tab').nth(2).click(); // Settings
+  await page.getByRole('button', { name: /^(Offline|Оффлайн)$/ }).click();
+  await expect(page.locator('header.nav.offline')).toBeVisible({ timeout: 15000 });
+  await page.getByRole('button', { name: /Back|Назад/i }).click();
+  await expect(page.locator('button.tab').nth(2)).toBeVisible();
+}
+
+// typePin clicks the on-screen keypad digits (the pad has no OK button — the 4th digit is the action).
+// It first waits for the dots to be empty, so a call made right after a previous entry does not lose
+// digits during the 250 ms verdict pause (the 4th digit → pause → clear/advance).
+async function typePin(page: Page, digits: string): Promise<void> {
+  await expect(page.locator('.pad .dot.on')).toHaveCount(0);
+  for (const d of digits) await page.locator('.pad .key', { hasText: d }).click();
+}
+
+test.describe('offline hotseat (pass-and-play)', () => {
+  test('create with a locked seat, unlock, host-skip, terminate from the lobby', async ({ page }) => {
+    await forceStandalone(page);
+    await page.goto('/');
+    await enterLobby(page);
+    await goOffline(page);
+
+    // A known seed: the bag deals a full rack deterministically, AND the seeded seating shuffle keeps
+    // the roster order (Ann first) so the locked-seat assertions below are stable. (Seat order is
+    // randomised at start; the shuffle is seed-driven — seed '1' would seat Bob first, '2' Ann first.)
+    await page.evaluate(() => (window as unknown as { __mock: { setLocalSeed(s: string): void } }).__mock.setLocalSeed('2'));
+
+    // New game -> the offline mode selector now offers "with friends" (hotseat).
+    await page.locator('button.tab').nth(0).click();
+    await page.getByRole('button', { name: /With friends|друзьями/i }).click();
+
+    // The player rows are disabled until the mandatory host (master) PIN is set.
+    await expect(page.locator('.pname').first()).toBeDisabled();
+
+    // Set the host PIN (enter + confirm), then decline taking a seat.
+    await page.locator('.hostpin .plink').click();
+    await typePin(page, '9999');
+    await typePin(page, '9999');
+    await page.getByRole('button', { name: /^(No|Нет)$/ }).click();
+
+    // Pick the English variant (the plaques mirror Quick Match; "Scrabble" is the Latin English name).
+    await page.locator('.variant', { hasText: 'Scrabble' }).click();
+
+    // Two players: Ann (PIN-locked) and Bob (open).
+    await page.locator('.pname').nth(0).fill('Ann');
+    await page.locator('.pname').nth(1).fill('Bob');
+
+    // Row-delete: a 3rd player's kebab asks the host PIN, which ARMS a ❌ (not a silent delete);
+    // tapping the ❌ removes the row.
+    await page.getByRole('button', { name: /Add player|Добавить/i }).click();
+    await expect(page.locator('.prow')).toHaveCount(3);
+    await page.locator('.prow').nth(2).locator('.pkebab').click();
+    await typePin(page, '9999');
+    const rowDel = page.locator('.prow').nth(2).locator('.prow-del');
+    await expect(rowDel).toBeVisible();
+    await rowDel.click();
+    await expect(page.locator('.prow')).toHaveCount(2);
+
+    // Lock Ann's seat with a PIN.
+    await page.locator('.prow').nth(0).locator('.plink').click();
+    await typePin(page, '1234');
+    await typePin(page, '1234');
+
+    await page.locator('button.invite').click();
+    await expect(page.locator('[data-cell]').first()).toBeVisible();
+
+    // Ann is to move and PIN-locked: the board is visible but her rack is withheld behind Unlock.
+    await expect(page.locator('.unlock')).toBeVisible();
+    await expect(page.locator('.rack .tile')).toHaveCount(0);
+
+    // A wrong PIN keeps it locked; the right PIN reveals the full rack.
+    await page.locator('.unlock').click();
+    await typePin(page, '0000');
+    await expect(page.locator('.pad')).toBeVisible(); // still open after a wrong PIN
+    await typePin(page, '1234');
+    await expect(page.locator('.rack .tile')).toHaveCount(7);
+
+    // Opening the history reveals NO social controls on the seat plaques (a local game is
+    // account-less), and the Dictionary entry (the comms button) is kept for the active game.
+    await page.locator('.scoreboard').click();
+    await expect(page.locator('.fico')).toHaveCount(0);
+    await expect(page.locator('.chat-ico')).toBeVisible();
+    await page.locator('.scoreboard').click();
+
+    // Host override: 🔐 -> master PIN -> skip the current turn -> confirm. The turn passes to Bob,
+    // whose seat is open, so his rack shows without a lock.
+    await page.locator('button.tab', { hasText: /Host|Ведущий/ }).click();
+    await typePin(page, '9999');
+    await page.getByRole('button', { name: /Skip|Пропустить/ }).click();
+    await page.getByRole('button', { name: /^(OK|ОК)$/ }).click();
+    await expect(page.locator('.unlock')).toHaveCount(0);
+    await expect(page.locator('.rack .tile')).toHaveCount(7);
+
+    // Back in the lobby the active hotseat game has a kebab; terminating it needs the master PIN.
+    await page.getByRole('button', { name: /Back|Назад/i }).click();
+    await expect(page.getByText('Ann', { exact: false }).first()).toBeVisible();
+    await expect(page.locator('.rowwrap')).toHaveCount(1);
+    await page.locator('.kebab').first().click();
+    const del = page.locator('.rowwrap.revealed .del');
+    await expect(del).toBeVisible();
+    await del.click();
+    await typePin(page, '9999');
+    await expect(page.locator('.rowwrap')).toHaveCount(0);
+  });
+});

ui/e2e/offline.spec.ts

@@ -0,0 +1,95 @@
+import { test, expect, type Page } from './fixtures';
+
+// The offline mode is gated to an installed standalone PWA with a confirmed email. The mock account
+// has an email; force the standalone display mode so the Settings offline toggle is offered. Only the
+// `(display-mode: standalone)` query is overridden — theme/reduce-motion queries pass through.
+async function forceStandalone(page: Page): Promise<void> {
+  await page.addInitScript(() => {
+    const orig = window.matchMedia.bind(window);
+    window.matchMedia = (q: string) =>
+      (q.includes('display-mode: standalone')
+        ? { matches: true, media: q, onchange: null, addEventListener() {}, removeEventListener() {}, addListener() {}, removeListener() {}, dispatchEvent: () => false }
+        : orig(q)) as MediaQueryList;
+  });
+}
+
+// After a load, land in the lobby. The mock cold-starts on the login screen (no seeded session), so
+// click through as guest. Waiting for the button (rather than a point-in-time count()) is what makes
+// this deterministic: a count() sampled during the pre-login splash frame returned 0, skipped the
+// click, and then hung — or latched a transient lobby tab-bar — instead of opening the real lobby.
+async function enterLobby(page: Page): Promise<void> {
+  await page.getByRole('button', { name: /guest|гост/i }).first().click();
+  // The lobby tab bar has three tabs in a fixed order: New (0), Stats (1), Settings (2). nth() is
+  // robust to locale, emoji variation selectors and the coachmark anchors (which the first-run
+  // onboarding strips after it completes).
+  await expect(page.locator('button.tab').nth(2)).toBeVisible();
+}
+
+// Pick a rack tile by its glyph and drop it on a board square (the rack of the pinned-seed game has
+// all-distinct letters, so the glyph is unambiguous).
+async function placeTile(page: Page, glyph: string, row: number, col: number): Promise<void> {
+  await page.locator('.rack .tile', { hasText: glyph }).first().click();
+  await page.locator(`[data-cell][data-row="${row}"][data-col="${col}"]`).click();
+}
+
+test.describe('offline mode', () => {
+  test('enter via the toggle, play a local vs_ai game, persist across a reload', async ({ page }) => {
+    await forceStandalone(page);
+    await page.goto('/');
+    await enterLobby(page);
+
+    // Online: a seeded online game (vs Ann) is listed.
+    await expect(page.getByText('Ann', { exact: false }).first()).toBeVisible();
+
+    // Enter offline through the real Settings toggle (its readiness check fetches every enabled
+    // variant's dawg, served from /e2edict/ by the mock) — the header turns blue with the chip.
+    await page.locator('button.tab').nth(2).click();
+    await page.getByRole('button', { name: /^(Offline|Оффлайн)$/ }).click();
+    await expect(page.locator('header.nav.offline')).toBeVisible({ timeout: 15000 });
+
+    // Back in the (now offline) lobby: the online games are hidden and the Stats tab is disabled.
+    await page.getByRole('button', { name: /Back|Назад/i }).click();
+    await expect(page.locator('button.tab').nth(2)).toBeVisible();
+    await expect(page.getByText('Ann', { exact: false })).toHaveCount(0);
+    await expect(page.locator('button.tab').nth(1)).toBeDisabled();
+
+    // Create a device-local English vs_ai game with a pinned bag seed (deals the rack NEWYMAO).
+    await page.evaluate(() => (window as unknown as { __mock: { setLocalSeed(s: string): void } }).__mock.setLocalSeed('1'));
+    await page.locator('button.tab').nth(0).click();
+    // The English variant's display name is "Scrabble" (Latin) in both locales — the Russian
+    // variants are "Скрэббл"/"Эрудит"/"Erudite", so this uniquely selects the English game.
+    await page.locator('.variant', { hasText: 'Scrabble' }).click();
+    await page.locator('button.invite').click();
+    await expect(page.locator('[data-cell]').first()).toBeVisible();
+
+    // The human's first move is not idle-gated: the hint is available at once (no 🔒 lock badge).
+    await expect(page.locator('.lock')).toHaveCount(0);
+
+    // The human plays WAY horizontally across the centre (7,5)-(7,7).
+    await placeTile(page, 'W', 7, 5);
+    await placeTile(page, 'A', 7, 6);
+    await placeTile(page, 'Y', 7, 7);
+    await expect(page.locator('[data-cell].pending')).toHaveCount(3);
+    await page.locator('.make').click();
+
+    // The play commits and the local robot replies with a real move, so the board carries more than
+    // WAY's three tiles.
+    await expect(async () => {
+      expect(await page.locator('[data-cell].filled').count()).toBeGreaterThan(3);
+    }).toPass({ timeout: 15000 });
+    const filled = await page.locator('[data-cell].filled').count();
+
+    // Now it is the human's turn again after the robot moved: the idle hint gate arms, so the hint
+    // button shows the 🔒 lock (it lifts after 30 idle minutes on a monotonic clock — not waited here).
+    await expect(page.locator('.lock')).toBeVisible();
+
+    // Reload: the hash router restores the /game/<id> route and the local game replays from
+    // IndexedDB with every committed tile intact.
+    await page.reload();
+    await expect(page.locator('[data-cell]').first()).toBeVisible();
+    await expect(page.locator('[data-cell].filled')).toHaveCount(filled);
+    // The idle-hint gate is persisted (a wall-clock unlock time), so the 🔒 survives the reload —
+    // the wait was not reset by relaunching.
+    await expect(page.locator('.lock')).toBeVisible();
+  });
+});

ui/e2e/router.spec.ts

@@ -0,0 +1,26 @@
+import { expect, test } from './fixtures';
+
+// The hash router must update its reactive `route` rune synchronously inside navigate(), not defer it
+// to the asynchronous `hashchange` event. Bootstrap flips `app.ready` in the same tick right after
+// `navigate('/login')` on an unauthenticated cold start; a route that trailed the hash for one frame
+// let App.svelte render the stale route (the empty-hash lobby) under the new login screen — a visible
+// lobby-shell flash plus a doomed games.list. It also made the offline e2e flaky: enterLobby could
+// latch that transient lobby tab-bar instead of clicking through the login screen.
+
+test('navigate updates the reactive route synchronously (no hashchange lag)', async ({ page }) => {
+  await page.goto('/');
+  // The bundle has loaded and installed the mock __router seam once the login screen is up.
+  await expect(page.getByRole('button', { name: /guest/i })).toBeVisible();
+
+  // Read the route in the SAME microtask as the navigate: the fix makes it the new route at once;
+  // the pre-fix code returned the previous route (it waited for the async hashchange).
+  const routeAfterNavigate = await page.evaluate(() => {
+    const r = (window as unknown as { __router: { navigate(p: string): void; route(): string } }).__router;
+    r.navigate('/settings');
+    return r.route();
+  });
+  expect(routeAfterNavigate).toBe('settings');
+
+  // The hash was written too, so a reload/back still resolves the same route.
+  expect(new URL(page.url()).hash).toBe('#/settings');
+});

ui/e2e/viewport.spec.ts

@@ -0,0 +1,69 @@
+import { test, expect, type Page } from './fixtures';
+
+// Playwright's WebKit has no real soft keyboard, so emulate iOS's visual-viewport behaviour: replace
+// window.visualViewport with a controllable fake BEFORE the app boots. The app's syncViewport
+// (app.svelte.ts) reads visualViewport.height/offsetTop and mirrors them into --vvh / --vv-top, which
+// position the pinned app-shell (app.css html.app-shell body). Driving the fake exercises the exact
+// code path the real keyboard triggers on iOS — where the layout viewport does NOT shrink and the
+// visual viewport instead offsets down toward the focused field.
+async function installFakeViewport(page: Page): Promise<void> {
+  await page.addInitScript(() => {
+    const fake = new EventTarget() as EventTarget & { height: number; offsetTop: number; width: number };
+    fake.height = window.innerHeight;
+    fake.offsetTop = 0;
+    fake.width = window.innerWidth;
+    Object.defineProperty(window, 'visualViewport', { configurable: true, value: fake });
+    (window as unknown as { __vv: typeof fake }).__vv = fake;
+  });
+}
+
+async function setViewport(page: Page, height: number, offsetTop: number): Promise<void> {
+  await page.evaluate(
+    ([h, t]) => {
+      const vv = (window as unknown as { __vv: { height: number; offsetTop: number; dispatchEvent(e: Event): boolean } }).__vv;
+      vv.height = h;
+      vv.offsetTop = t;
+      vv.dispatchEvent(new Event('resize'));
+      vv.dispatchEvent(new Event('scroll'));
+    },
+    [height, offsetTop],
+  );
+}
+
+async function shell(page: Page): Promise<{ vvh: string; top: string; bodyTop: string }> {
+  return page.evaluate(() => ({
+    vvh: getComputedStyle(document.documentElement).getPropertyValue('--vvh').trim(),
+    top: getComputedStyle(document.documentElement).getPropertyValue('--vv-top').trim(),
+    bodyTop: getComputedStyle(document.body).top,
+  }));
+}
+
+test.describe('visual-viewport shell (soft-keyboard alignment)', () => {
+  test('the pinned shell follows the visual viewport height AND offset', async ({ page }) => {
+    await installFakeViewport(page);
+    await page.goto('/');
+    await expect(page.locator('html.app-shell')).toBeAttached();
+    const innerH = await page.evaluate(() => window.innerHeight);
+
+    // Keyboard closed: full height, no offset.
+    await setViewport(page, innerH, 0);
+    let s = await shell(page);
+    expect(s.top).toBe('0px');
+    expect(s.bodyTop).toBe('0px');
+
+    // Keyboard open + iOS offset: the visual viewport shrinks AND offsets down. The pinned shell must
+    // follow BOTH — the body's top must equal the offset (not stay at 0), else the top-anchored
+    // content shows empty space below (the iOS bug this fixes).
+    await setViewport(page, innerH - 300, 180);
+    s = await shell(page);
+    expect(s.vvh).toBe(`${innerH - 300}px`);
+    expect(s.top).toBe('180px');
+    expect(s.bodyTop).toBe('180px');
+
+    // Keyboard closed again: the offset reverts to 0 — no stale shift left behind.
+    await setViewport(page, innerH, 0);
+    s = await shell(page);
+    expect(s.top).toBe('0px');
+    expect(s.bodyTop).toBe('0px');
+  });
+});

ui/package.json

@@ -32,6 +32,10 @@
     "svelte-check": "^4.1.0",
     "typescript": "^5.7.0",
     "vite": "^6.0.0",
-    "vitest": "^3.0.0"
+    "vite-plugin-pwa": "^0.21.2",
+    "vitest": "^3.0.0",
+    "workbox-core": "^7.4.1",
+    "workbox-precaching": "^7.4.1",
+    "workbox-routing": "^7.4.1"
   }
 }

ui/playwright.config.ts

@@ -21,8 +21,11 @@ export default defineConfig({
     // under /app/ and /telegram/): served from the preview root, an absolute base keeps assets at
     // /assets/ so the SPA-fallback also boots a subpath like /telegram/. Base only prefixes asset
     // URLs, so the minified JS under test is identical to the contour's.
+    // After the mock build, copy the real per-variant dawgs into the preview output (dist-e2e) so the
+    // offline spec can play a real local vs_ai game; the files are e2e-only (never committed, never in
+    // the production build). Source: E2E_DICT_DIR (CI: the fetched release; local: the sibling).
     command:
-      'pnpm exec vite build --mode mock --base / --outDir dist-e2e --emptyOutDir && pnpm exec vite preview --outDir dist-e2e --port 4173 --strictPort',
+      'pnpm exec vite build --mode mock --base / --outDir dist-e2e --emptyOutDir && node scripts/e2e-dict.mjs && pnpm exec vite preview --outDir dist-e2e --port 4173 --strictPort',
     url: 'http://localhost:4173',
     reuseExistingServer: !process.env.CI,
     timeout: 120_000,

ui/public/sw.js

@@ -1,53 +0,0 @@
-// Install-only service worker.
-//
-// Its sole job today is to satisfy Chromium's PWA installability requirement (a registered
-// service worker with a fetch handler) so the web app can be installed to the home screen /
-// desktop — notably on Android, where the manifest alone is not enough. It deliberately does
-// NOT cache assets or the Connect-RPC stream: only top-level navigations are handled,
-// network-first with a cached-shell fallback, so the live app, its immutable hashed assets and
-// the live event stream are never served stale.
-//
-// This is the single designated growth point for the planned offline mode (a Settings toggle,
-// default online — see docs/ARCHITECTURE.md). Extend the fetch router here; keep the same
-// /app/ scope; gate any real caching behind the toggle and coordinate updates with the boot
-// version guard.
-const SHELL = 'scrabble-shell-v1'; // bump only when the SW strategy itself changes.
-
-self.addEventListener('install', () => {
-  // No cached content to migrate carefully, so activate the new worker immediately.
-  self.skipWaiting();
-});
-
-self.addEventListener('activate', (event) => {
-  event.waitUntil(
-    (async () => {
-      const keys = await caches.keys();
-      await Promise.all(keys.filter((k) => k !== SHELL).map((k) => caches.delete(k)));
-      await self.clients.claim();
-    })(),
-  );
-});
-
-self.addEventListener('fetch', (event) => {
-  const req = event.request;
-  // Only top-level navigations are handled. Hashed assets and the Connect-RPC requests are
-  // left untouched (no respondWith -> the browser performs its default fetch), so the worker
-  // can never break the live stream or serve a stale immutable asset.
-  if (req.mode !== 'navigate') return;
-  event.respondWith(
-    (async () => {
-      try {
-        const res = await fetch(req);
-        const cache = await caches.open(SHELL);
-        // One shell entry regardless of the deep-link path: the hash router resolves the route
-        // client-side, so any offline navigation can be served the same cached shell.
-        cache.put('shell', res.clone());
-        return res;
-      } catch {
-        const cache = await caches.open(SHELL);
-        const cached = await cache.match('shell');
-        return cached ?? Response.error();
-      }
-    })(),
-  );
-});

ui/scripts/bundle-size.mjs

@@ -20,10 +20,16 @@ import { join } from 'node:path';
 const DIST = 'dist';
 
 // Per-chunk gzip budgets in KB. The app entry was raised to 110 for the local move-preview
-// wiring, then to 112 for the PWA install feature (the install CTA + the pwa detection /
-// service-worker registration live in the app entry; the heavy dict subsystem stays in lazy
-// chunks). Its scoped CSS lands in the CSS chunk, not this JS budget.
-const BUDGET = { app: 112, shared: 30, landing: 5 };
+// wiring, to 112 for the PWA install feature, to 113 for the offline-mode wiring, to 114 for
+// the offline auto-detect (the cold-start reachability check and the "no connection" dialog live in
+// the boot path), then to 115 for the vs_ai idle-hint gate — its monotonic clock, lock badge and
+// countdown toast live in the always-loaded game screen (Game.svelte) — and to 120 for the offline
+// pass-and-play (hotseat) mode: the on-screen PIN pad, the creation roster and the in-game host menu
+// live in the always-loaded New Game / Game / Lobby screens (the offline engine and the tiny PIN
+// hashing stay in lazy chunks / are negligible). The heavy parts — the dict loader, the move
+// generator and the preload orchestration — still stay in lazy chunks. Scoped CSS lands in the CSS
+// chunk, not this JS budget.
+const BUDGET = { app: 120, shared: 30, landing: 5 };
 
 // gzipped returns the gzipped byte size of a built asset, or 0 when the reference is not a
 // local file (e.g. the Telegram SDK loaded from a CDN) or is missing.

ui/scripts/e2e-dict.mjs

@@ -0,0 +1,35 @@
+// Copies the real per-variant dictionary DAWGs into the mock e2e preview output (dist-e2e/e2edict/)
+// so the offline spec can create and play a real local vs_ai game (the mock's fetchDict serves these
+// files — see lib/mock/client.ts). The dawgs are NEVER committed and never enter the production
+// build; they live only in the throwaway dist-e2e/ that `vite preview` serves for Playwright.
+//
+// Source directory: E2E_DICT_DIR — in CI the fetched scrabble-dictionary release
+// ($GITHUB_WORKSPACE/dawg); locally it defaults to the sibling scrabble-solver/dawg checkout. A
+// missing source only warns (so the other, dawg-free specs still run); the offline spec then fails
+// with an obvious HTTP 404 from fetchDict.
+
+import { existsSync, mkdirSync, copyFileSync } from 'node:fs';
+import { join } from 'node:path';
+
+const srcDir = process.env.E2E_DICT_DIR ?? '../../scrabble-solver/dawg';
+const outDir = 'dist-e2e/e2edict';
+
+// The app's Variant enum value -> the release dawg file name (matches the movegen/parity mapping).
+const dawgFor = {
+  scrabble_en: 'en_sowpods',
+  scrabble_ru: 'ru_scrabble',
+  erudit_ru: 'ru_erudit',
+};
+
+mkdirSync(outDir, { recursive: true });
+let copied = 0;
+for (const [variant, file] of Object.entries(dawgFor)) {
+  const src = join(srcDir, `${file}.dawg`);
+  if (!existsSync(src)) {
+    console.warn(`e2e-dict: missing ${src} — the offline spec will 404 (set E2E_DICT_DIR)`);
+    continue;
+  }
+  copyFileSync(src, join(outDir, `${variant}.dawg`));
+  copied++;
+}
+console.log(`e2e-dict: copied ${copied}/${Object.keys(dawgFor).length} dawgs from ${srcDir} -> ${outDir}`);

ui/src/App.svelte

@@ -1,7 +1,7 @@
 <script lang="ts">
   import { onMount } from 'svelte';
   import { cubicOut } from 'svelte/easing';
-  import { app, bootstrap } from './lib/app.svelte';
+  import { app, bootstrap, resolveOfflinePrompt } from './lib/app.svelte';
   import { router, type RouteName } from './lib/router.svelte';
   import { t } from './lib/i18n/index.svelte';
   import Toast from './components/Toast.svelte';
@@ -136,6 +136,21 @@
 <Coachmark />
 <MaintenanceOverlay />
 
+<!-- Cold-start "no connection" dialog: the reachability check timed out with the network interface
+     reportedly online, so it is ambiguous. The player chooses to go offline (play local vs_ai) or to
+     keep trying to connect. bootstrap awaits this choice (app.offlinePrompt). -->
+{#if app.offlinePrompt}
+  <div class="offprompt" role="dialog" aria-modal="true">
+    <div class="card">
+      <p class="msg">{t('offline.promptTitle')}</p>
+      <div class="acts">
+        <button class="opt primary" onclick={() => resolveOfflinePrompt(true)}>{t('offline.promptYes')}</button>
+        <button class="opt" onclick={() => resolveOfflinePrompt(false)}>{t('offline.promptNo')}</button>
+      </div>
+    </div>
+  </div>
+{/if}
+
 {#if routeIsLobby && !app.splashDone && !app.blocked && !app.bootError && !app.launchError}
   <Splash />
 {/if}
@@ -145,6 +160,49 @@
 {/if}
 
 <style>
+  /* The cold-start "no connection" dialog — a centred card over a scrim, above the splash. */
+  .offprompt {
+    position: fixed;
+    inset: 0;
+    z-index: 100;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    background: rgba(0, 0, 0, 0.5);
+    padding: var(--pad);
+  }
+  .offprompt .card {
+    background: var(--bg-elev);
+    border: 1px solid var(--border);
+    border-radius: var(--radius-sm);
+    padding: 20px;
+    max-width: 320px;
+    width: 100%;
+    text-align: center;
+  }
+  .offprompt .msg {
+    margin: 0 0 16px;
+    font-size: 1rem;
+    color: var(--text);
+  }
+  .offprompt .acts {
+    display: flex;
+    flex-direction: column;
+    gap: 8px;
+  }
+  .offprompt .opt {
+    padding: 11px 16px;
+    border: 1px solid var(--border);
+    border-radius: var(--radius-sm);
+    background: var(--surface);
+    color: var(--text);
+    font-size: 0.95rem;
+  }
+  .offprompt .opt.primary {
+    background: var(--accent);
+    color: var(--accent-text);
+    border-color: var(--accent);
+  }
   .splash {
     height: 100%;
     display: grid;

ui/src/app.css

@@ -162,7 +162,15 @@ html.app-shell {
 }
 html.app-shell body {
   position: fixed;
-  inset: 0;
+  /* Follow the visual viewport (top + height), not merely fill the layout viewport: iOS Safari /
+     WKWebView does not shrink the layout viewport for the soft keyboard — it offsets the visual
+     viewport down toward the focused field — so a top-anchored (inset:0) shell would misalign, showing
+     empty space below the content (worst on a repeat focus). --vv-top / --vvh are kept in sync from
+     app.svelte.ts (syncViewport). The fallbacks equal inset:0 before the first sync / on the landing. */
+  top: var(--vv-top, 0px);
+  left: 0;
+  right: 0;
+  height: var(--vvh, 100%);
   overflow: hidden;
 }
 

ui/src/components/Header.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
   import { navigate } from '../lib/router.svelte';
   import { connection } from '../lib/connection.svelte';
+  import { offlineMode, dictPreloadWarning } from '../lib/offline.svelte';
   import { t } from '../lib/i18n/index.svelte';
   import { app, openDebug } from '../lib/app.svelte';
   import Spinner from './Spinner.svelte';
@@ -27,7 +28,7 @@
   }
 </script>
 
-<header class="nav" class:grow>
+<header class="nav" class:grow class:offline={offlineMode.active}>
   <div class="bar">
     {#if showBack}
       <button class="icon back" onclick={() => back && navigate(back)} aria-label="Back">
@@ -36,15 +37,20 @@
     {:else}
       <span class="spacer"></span>
     {/if}
-    {#if connection.online}
+    {#if connection.online || offlineMode.active}
       <!-- svelte-ignore a11y_click_events_have_key_events -->
       <!-- svelte-ignore a11y_no_noninteractive_element_interactions -->
       <h1 onclick={onTitleTap}>{title}</h1>
     {:else}
       <h1 class="connecting"><Spinner /> <span>{t('connection.connecting')}</span></h1>
     {/if}
-    <!-- A right-hand spacer balances the back button so the title stays centred. -->
-    <span class="spacer"></span>
+    <!-- A right-hand spacer balances the back button so the title stays centred; in offline mode it
+         carries the "Offline" chip so the deliberate mode is always visible (not just the blue tint). -->
+    {#if offlineMode.active}
+      <span class="chip">{t('settings.offline')}</span>
+    {:else}
+      <span class="spacer"></span>
+    {/if}
   </div>
   <!-- The ad banner lives inside the nav, directly under the title bar, so it sits in the
        same place on every screen — and in the game (grown nav) the spare height falls below
@@ -52,7 +58,11 @@
        coachmark overlay is up (app.coachActive) so the scrolling strip does not run behind the
        dimmed onboarding layer; the engine keeps rotating (module scope) and the strip reappears,
        per this same condition, once onboarding closes. -->
-  {#if app.profile?.banner && app.profile.banner.campaigns.length && !app.coachActive}
+  {#if dictPreloadWarning.active}
+    <!-- A background dictionary preload for offline readiness failed (poor connection): a soft
+         notice takes the ad banner's slot until a later preload succeeds and clears it. -->
+    <p class="preload-warn" role="alert">{t('offline.preloadWarning')}</p>
+  {:else if app.profile?.banner && app.profile.banner.campaigns.length && !app.coachActive}
     <AdBanner
       campaigns={app.profile.banner.campaigns}
       timings={app.profile.banner.timings}
@@ -74,6 +84,12 @@
     user-select: none;
     -webkit-user-select: none;
   }
+  /* Deliberate offline mode: a blue-tinted nav, mixed from the accent so it tracks the light/dark
+     theme (and any Telegram theme override) — the offline state is unmistakable at a glance. */
+  .nav.offline {
+    background: color-mix(in srgb, var(--accent) 20%, var(--bg-elev));
+    border-bottom-color: color-mix(in srgb, var(--accent) 35%, var(--border));
+  }
   .nav.grow {
     /* Grow into spare height (banner under the title, the board pinned to the bottom), but
        never shrink: on a short viewport the banner keeps its height and the board's own
@@ -114,6 +130,34 @@
     align-items: center;
     justify-content: center;
   }
+  /* The offline chip: a compact accent-tinted pill in the header's right slot. */
+  .chip {
+    min-width: 40px;
+    height: 24px;
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    padding: 0 8px;
+    font-size: 0.72rem;
+    font-weight: 600;
+    color: var(--accent);
+    background: color-mix(in srgb, var(--accent) 16%, transparent);
+    border: 1px solid color-mix(in srgb, var(--accent) 45%, transparent);
+    border-radius: 999px;
+    white-space: nowrap;
+  }
+  /* The offline-readiness preload warning: a soft, muted strip in the ad banner's slot, sized like
+     the banner region so the bar does not jump when it appears. */
+  .preload-warn {
+    margin: 0;
+    padding: 7px var(--pad);
+    font-size: 0.78rem;
+    line-height: 1.3;
+    text-align: center;
+    color: var(--text-muted);
+    background: var(--surface-2);
+    border-top: 1px solid var(--border);
+  }
   .back {
     background: none;
     border: none;

ui/src/components/PinPad.svelte

@@ -0,0 +1,268 @@
+<script lang="ts">
+  // Apple-lock-screen-style 4-digit PIN pad for offline pass-and-play (hotseat) games.
+  // Modes:
+  //   set     — enter a PIN, then repeat it to confirm; emits { kind: 'set', lock }.
+  //   verify  — enter a PIN; runs `verify(pin)` on the 4th digit; emits { kind: 'verified' }
+  //             or shakes + clears on a wrong PIN.
+  //   change  — run `verify` on the current PIN, then offer "set a new PIN" (the set flow)
+  //             or, when allowRemove, "remove PIN" ({ kind: 'removed' }).
+  // Verification is delegated to the caller's `verify` callback: at creation time it checks a
+  // UI-held lock (lib/pin verifyPin); in-game it delegates to the local source (which holds the
+  // stored lock). The pad never shows an OK button: entering the 4th digit is the action. PIN
+  // storage is a social lock, not cryptography — see lib/pin.ts.
+  import Modal from './Modal.svelte';
+  import { t } from '../lib/i18n/index.svelte';
+  import { newLock, type PinLock } from '../lib/pin';
+
+  /** PinResult is the outcome handed to onresult when the pad completes. */
+  export type PinResult =
+    | { kind: 'set'; lock: PinLock }
+    | { kind: 'verified' }
+    | { kind: 'removed' };
+
+  let {
+    mode,
+    title = '',
+    verify,
+    allowRemove = false,
+    onclose,
+    onresult,
+  }: {
+    mode: 'set' | 'verify' | 'change';
+    title?: string;
+    /** Verifies an entered PIN (required for 'verify' and 'change'). */
+    verify?: (pin: string) => Promise<boolean>;
+    allowRemove?: boolean;
+    onclose?: () => void;
+    onresult: (r: PinResult) => void;
+  } = $props();
+
+  const LEN = 4;
+
+  // 'old' verifies the existing PIN (change); 'menu' offers set-new / remove (change);
+  // 'enter' collects a PIN; 'confirm' re-enters it (set / change→new). `mode` is fixed
+  // for the pad's lifetime (callers mount a fresh pad per operation), so capturing its
+  // initial value here is intentional.
+  // svelte-ignore state_referenced_locally
+  let phase = $state<'old' | 'menu' | 'enter' | 'confirm'>(mode === 'change' ? 'old' : 'enter');
+  let buffer = $state('');
+  let first = $state(''); // the first entry, awaiting confirmation
+  let error = $state(false); // drives the error prompt + shake
+  let shakeSeq = $state(0); // bumped on each error to replay the shake animation
+  let busy = $state(false); // guards the async check between the 4th digit and the outcome
+
+  function promptText(): string {
+    if (error) return phase === 'confirm' ? t('pin.mismatch') : t('pin.wrong');
+    switch (phase) {
+      case 'old':
+        return t('pin.enterCurrent');
+      case 'confirm':
+        return t('pin.repeat');
+      default:
+        return mode === 'verify' ? t('pin.enter') : t('pin.create');
+    }
+  }
+
+  function fail(): void {
+    buffer = '';
+    error = true;
+    shakeSeq += 1;
+  }
+
+  async function commit(): Promise<void> {
+    busy = true;
+    try {
+      // Let the 4th dot register before the verdict: a beat so the fill (and, on failure, the shake)
+      // reads as a deliberate response rather than an instant flicker.
+      await new Promise((r) => setTimeout(r, 250));
+      if (phase === 'old') {
+        if (verify && (await verify(buffer))) {
+          buffer = '';
+          error = false;
+          phase = 'menu';
+        } else fail();
+      } else if (phase === 'enter' && mode === 'verify') {
+        if (verify && (await verify(buffer))) onresult({ kind: 'verified' });
+        else fail();
+      } else if (phase === 'enter') {
+        first = buffer;
+        buffer = '';
+        error = false;
+        phase = 'confirm';
+      } else if (phase === 'confirm') {
+        if (buffer === first) onresult({ kind: 'set', lock: await newLock(buffer) });
+        else {
+          first = '';
+          phase = 'enter';
+          fail();
+        }
+      }
+    } finally {
+      busy = false;
+    }
+  }
+
+  function press(d: string): void {
+    if (busy || phase === 'menu' || buffer.length >= LEN) return;
+    error = false;
+    buffer += d;
+    if (buffer.length === LEN) void commit();
+  }
+
+  function back(): void {
+    if (busy || phase === 'menu') return;
+    buffer = buffer.slice(0, -1);
+  }
+
+  function startNew(): void {
+    error = false;
+    first = '';
+    buffer = '';
+    phase = 'enter';
+  }
+
+  function onkey(e: KeyboardEvent): void {
+    if (e.key >= '0' && e.key <= '9') {
+      press(e.key);
+      e.preventDefault();
+    } else if (e.key === 'Backspace') {
+      back();
+      e.preventDefault();
+    } else if (e.key === 'Escape') {
+      onclose?.();
+    }
+  }
+
+  const keys = ['1', '2', '3', '4', '5', '6', '7', '8', '9'];
+  const slots = Array.from({ length: LEN }, (_, i) => i);
+</script>
+
+<svelte:window onkeydown={onkey} />
+
+<Modal {title} {onclose} overlayKeyboard>
+  <div class="pad">
+    {#if phase === 'menu'}
+      <div class="menu">
+        <button class="opt" onclick={startNew}>{t('pin.setNew')}</button>
+        {#if allowRemove}
+          <button class="opt danger" onclick={() => onresult({ kind: 'removed' })}>
+            {t('pin.remove')}
+          </button>
+        {/if}
+      </div>
+    {:else}
+      <p class="prompt" class:err={error}>{promptText()}</p>
+      {#key shakeSeq}
+        <div class="dots" class:shake={error} aria-hidden="true">
+          {#each slots as i}
+            <span class="dot" class:on={i < buffer.length}></span>
+          {/each}
+        </div>
+      {/key}
+      <div class="grid">
+        {#each keys as k}
+          <button class="key" onclick={() => press(k)} aria-label={k}>{k}</button>
+        {/each}
+        <span class="key spacer"></span>
+        <button class="key" onclick={() => press('0')} aria-label="0">0</button>
+        <button class="key back" onclick={back} aria-label="⌫" disabled={buffer.length === 0}>⌫</button>
+      </div>
+    {/if}
+  </div>
+</Modal>
+
+<style>
+  .pad {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 16px;
+    padding-top: 4px;
+  }
+  .prompt {
+    margin: 0;
+    font-size: 0.95rem;
+    color: var(--muted, var(--text));
+    min-height: 1.2em;
+  }
+  .prompt.err {
+    color: var(--danger);
+  }
+  .dots {
+    display: flex;
+    gap: 16px;
+  }
+  .dot {
+    width: 14px;
+    height: 14px;
+    border-radius: 50%;
+    border: 1.5px solid var(--text);
+    box-sizing: border-box;
+  }
+  .dot.on {
+    background: var(--text);
+  }
+  .shake {
+    animation: shake 0.32s ease;
+  }
+  @keyframes shake {
+    0%, 100% { transform: translateX(0); }
+    20% { transform: translateX(-7px); }
+    40% { transform: translateX(7px); }
+    60% { transform: translateX(-5px); }
+    80% { transform: translateX(5px); }
+  }
+  .grid {
+    display: grid;
+    grid-template-columns: repeat(3, 1fr);
+    gap: 12px;
+  }
+  .key {
+    width: 62px;
+    height: 62px;
+    border-radius: 50%;
+    border: 1px solid var(--border);
+    background: var(--surface);
+    color: var(--text);
+    font-size: 1.4rem;
+    font-weight: 500;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+  }
+  .key:active {
+    background: var(--accent);
+    color: var(--accent-text);
+  }
+  .key.back {
+    border-color: transparent;
+    background: transparent;
+    font-size: 1.2rem;
+  }
+  .key.back:disabled {
+    opacity: 0.3;
+  }
+  .key.spacer {
+    border: none;
+    background: none;
+    pointer-events: none;
+  }
+  .menu {
+    display: flex;
+    flex-direction: column;
+    gap: 10px;
+    width: 100%;
+  }
+  .opt {
+    padding: 14px;
+    border: 1px solid var(--border);
+    background: var(--surface);
+    color: var(--text);
+    border-radius: var(--radius);
+    font-weight: 600;
+  }
+  .opt.danger {
+    border-color: var(--danger);
+    color: var(--danger);
+  }
+</style>

ui/src/game/CheckScreen.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
   import { onMount } from 'svelte';
   import { gateway } from '../lib/gateway';
+  import { gameSource, isLocalGameId } from '../lib/gamesource';
   import { handleError, showToast } from '../lib/app.svelte';
   import { t } from '../lib/i18n/index.svelte';
   import { alphabetLetters } from '../lib/alphabet';
@@ -20,8 +21,10 @@
 
   onMount(async () => {
     try {
-      // Include the alphabet so input sanitising + the check accept the variant's letters.
-      const st = await gateway.gameState(id, true);
+      // Include the alphabet so input sanitising + the check accept the variant's letters. Routed
+      // through gameSource so an offline (local) game resolves its state from the device, not the
+      // network.
+      const st = await gameSource(id).gameState(id, true);
       variant = st.game.variant;
     } catch (e) {
       handleError(e);
@@ -41,7 +44,7 @@
     cooling = true;
     setTimeout(() => (cooling = false), 5000);
     try {
-      const r = await gateway.checkWord(id, w, variant);
+      const r = await gameSource(id).checkWord(id, w, variant);
       checked.set(w, r.legal);
       result = { word: w, legal: r.legal };
     } catch (e) {
@@ -77,7 +80,11 @@
         : t('game.wordIllegal', { word: result.word })}
     </p>
     <div class="actions">
-      <button class="complain" onclick={complain}>{t('game.complain')}</button>
+      <!-- Complaints go to the admin over the network; a local (offline) game has no backend to
+           receive them, so the control is dropped there. -->
+      {#if !isLocalGameId(id)}
+        <button class="complain" onclick={complain}>{t('game.complain')}</button>
+      {/if}
       {#if result.legal}
         <a
           class="lookup"

ui/src/game/CommsHub.svelte

@@ -16,15 +16,21 @@
   // The game is rendered (and cached) before its comms open, so the cache tells us whether
   // it is still active without another fetch; an unknown game keeps the Dictionary offered.
   const active = $derived(getCachedGame(id)?.view.game.status !== 'finished');
-  // An honest-AI game has no chat at all, so its hub is Dictionary-only.
-  const vsAi = $derived(getCachedGame(id)?.view.game.vsAi ?? false);
+  // A local game has NO chat: an honest-AI game (vs_ai) and an offline pass-and-play (hotseat) game.
+  // Its hub is Dictionary-only.
+  const chatless = $derived(
+    (getCachedGame(id)?.view.game.vsAi ?? false) || (getCachedGame(id)?.view.game.hotseat ?? false),
+  );
   // Seeded once from the entry route's tab, then owned locally. The effect keeps the tab valid:
-  // an AI game has only the Dictionary; a finished non-AI game has only Chat (a stale Dictionary
+  // a chatless game has only the Dictionary; a finished non-AI game has only Chat (a stale Dictionary
   // deep-link falls back to Chat).
+  // A chatless game starts on the Dictionary regardless of the entry route — this keeps ChatScreen
+  // (which fetches chat over the network) from mounting even for a beat, which would otherwise raise
+  // an error toast in offline mode.
   // svelte-ignore state_referenced_locally
-  let tab = $state<CommsTab>(initialTab);
+  let tab = $state<CommsTab>(chatless ? 'dictionary' : initialTab);
   $effect(() => {
-    if (vsAi) tab = 'dictionary';
+    if (chatless) tab = 'dictionary';
     else if (tab === 'dictionary' && !active) tab = 'chat';
   });
 </script>
@@ -43,7 +49,7 @@
 
   {#snippet tabbar()}
     <TabBar>
-      {#if !vsAi}
+      {#if !chatless}
         <button class="tab" class:active={tab === 'chat'} onclick={() => (tab = 'chat')}>
           <span class="face"><span class="sq" aria-hidden="true">💬</span><span class="lbl">{t('game.chat')}</span></span>
         </button>

ui/src/game/Game.svelte

@@ -4,24 +4,28 @@
   import TabBar from '../components/TabBar.svelte';
   import TapConfirm from '../components/TapConfirm.svelte';
   import Modal from '../components/Modal.svelte';
+  import PinPad from '../components/PinPad.svelte';
   import DictWarmup from '../components/DictWarmup.svelte';
   import Board from './Board.svelte';
   import Rack from './Rack.svelte';
   import { gateway } from '../lib/gateway';
+  import { gameSource, localSource, isLocalGameId } from '../lib/gamesource';
   import { notePreviewLocal, notePreviewNetwork } from '../lib/localeval-metrics';
   import { navigate } from '../lib/router.svelte';
   import { app, handleError, showToast, markChatRead, seedChatUnread } from '../lib/app.svelte';
   import { connection } from '../lib/connection.svelte';
+  import { offlineMode } from '../lib/offline.svelte';
   import { GatewayError } from '../lib/client';
   import { t, type MessageKey } from '../lib/i18n/index.svelte';
   import type { EvalResult, MoveRecord, MoveResult, StateView, Tile } from '../lib/model';
   import { lastMoveCells, replay } from '../lib/board';
   import { badgeKind } from '../lib/unread';
+  import { seatMedal } from '../lib/result';
   import { historyGrid } from '../lib/history';
   import { centre, premiumGrid } from '../lib/premiums';
   import { variantNameKey, usesStarBlank, BLANK_STAR } from '../lib/variants';
   import { alphabetLetters, hasAlphabet } from '../lib/alphabet';
-  import { hintsLeft } from '../lib/hints';
+  import { hintsLeft, hintGateRemainingMs, hintLockMinutes, HINT_GATE_MS } from '../lib/hints';
   import { downloadUrl, shareOrDownloadGcg, shareUrlAsFile } from '../lib/share';
   import { insideVK, vkAndroidWebView, vkCopyText, vkDownloadFile, vkPlatform, vkShowImages } from '../lib/vk';
   import { getCachedGame, setCachedGame, setCachedDraft, type CachedGame } from '../lib/gamecache';
@@ -47,6 +51,18 @@
 
   let { id }: { id: string } = $props();
 
+  // The game's source: the local engine for an offline game id, otherwise the network gateway. The
+  // screen calls the game-loop methods (state/history/submit/pass/exchange/resign/hint/evaluate/
+  // draft) through it, so the same UI drives a local vs_ai game and an online one alike.
+  const source = $derived(gameSource(id));
+  // A local (offline) game plays entirely on-device, so it is always ready; an online game needs a
+  // live connection — and offline mode's kill switch refuses its calls — so its network actions are
+  // disabled while disconnected or in offline mode (which also stops the "something went wrong"
+  // toasts a blocked call would otherwise raise).
+  const netReady = $derived(isLocalGameId(id) || (connection.online && !offlineMode.active));
+  // Unsubscribes from a local game's robot-reply events (offline only; null for a network game).
+  let localUnsub: (() => void) | null = null;
+
   let view = $state<StateView | null>(null);
   let moves = $state<MoveRecord[]>([]);
   let placement = $state<Placement>(newPlacement([]));
@@ -149,10 +165,42 @@
   const playable = $derived(!!view && (view.game.status === 'active' || view.game.status === 'open'));
   const isMyTurn = $derived(!!view && playable && view.game.toMove === view.seat);
   const gameOver = $derived(!!view && view.game.status === 'finished');
+  // Offline hotseat: the seat to move is PIN-locked until its owner enters the seat PIN this turn.
+  // While locked the board stays visible but the rack is withheld and the move controls disabled;
+  // canMove folds the lock into isMyTurn (locked is always false for a network / vs_ai game).
+  const locked = $derived(!!view?.locked);
+  const canMove = $derived(isMyTurn && !locked);
   // The hint badge: this game's allowance remaining plus the LIVE global wallet. Reading the
   // wallet from the profile (not the per-game view snapshot) keeps it correct after a wallet
   // hint was spent in another game (see lib/hints).
   const hintCount = $derived(hintsLeft(view, app.profile?.hintBalance ?? 0));
+  // A vs_ai game's hint is unlimited and wallet-free, but idle-gated (an anti-frustration aid: it
+  // unlocks only after the player has been stuck ~30 min on a turn). The source (the SERVER clock
+  // online, the device clock offline) tells us the SECONDS LEFT (view.hintUnlockLeftSeconds); we
+  // anchor a MONOTONIC countdown (performance.now()) to it, so a client clock change cannot skew it.
+  // A fresh value arrives on load (armHintGate below); when the robot moves the wait is the full
+  // window. `monoNow` ticks so the 🔒 lifts live at the mark.
+  let hintGateStart = $state<number | null>(null); // performance.now() at the last anchor; null = open
+  let gateLeftMs = $state(0);
+  let monoNow = $state(performance.now());
+  const hintRemaining = $derived(hintGateRemainingMs(hintGateStart, gateLeftMs, monoNow));
+  const hintGated = $derived(hintRemaining > 0);
+  // Anchor the countdown to a freshly received seconds-left (or open the gate). Called on every state
+  // load from the view, and on the robot's move to the full window (the robot just moved).
+  function armHintGate(leftSeconds: number): void {
+    if (leftSeconds > 0) {
+      hintGateStart = performance.now();
+      gateLeftMs = leftSeconds * 1000;
+    } else {
+      hintGateStart = null;
+      gateLeftMs = 0;
+    }
+  }
+  $effect(() => {
+    if (!view?.game.vsAi) return;
+    const iv = setInterval(() => (monoNow = performance.now()), 10_000);
+    return () => clearInterval(iv);
+  });
   // RACK_SIZE mirrors the engine's rules.RackSize (7 for every current variant). The exchange
   // gate is only a UX guard: the backend stays the source of truth and rejects an under-supplied
   // exchange regardless (engine rejects when bag.Len() < rules.RackSize).
@@ -190,11 +238,13 @@
       // Fetch the saved draft alongside state and history (best-effort) so the composition is
       // applied in the same tick the board appears — never as a second, visible rack→board step.
       const [st, hist, draft] = await Promise.all([
-        gateway.gameState(id, includeAlphabet),
-        gateway.gameHistory(id),
-        gateway.draftGet(id).catch(() => ''),
+        source.gameState(id, includeAlphabet),
+        source.gameHistory(id),
+        source.draftGet(id).catch(() => ''),
       ]);
       view = st;
+      // Anchor the vs_ai idle-hint countdown to the freshly fetched seconds-left (0 = open / non-vs_ai).
+      armHintGate(st.game.vsAi ? (st.hintUnlockLeftSeconds ?? 0) : 0);
       syncWallet(st.walletBalance);
       // Seed the unread flag from the authoritative state (the live stream only raises it).
       seedChatUnread(id, st.game.unreadChat, st.game.unreadMessages);
@@ -220,7 +270,7 @@
     setCachedDraft(id, json);
     if (draftSaveTimer) clearTimeout(draftSaveTimer);
     draftSaveTimer = setTimeout(() => {
-      void gateway.draftSave(id, json).catch(() => {});
+      void source.draftSave(id, json).catch(() => {});
     }, 500);
   }
   // applyDraft restores the player's saved composition over a freshly loaded state: the rack
@@ -247,6 +297,9 @@
     if (cached) {
       view = cached.view;
       moves = cached.moves;
+      // Arm the vs_ai idle-hint countdown from the cached seconds-left so the 🔒 shows at once on a
+      // warm open (no wait for load()); the cached value is a snapshot, refreshed by load() below.
+      armHintGate(cached.view.game.vsAi ? (cached.view.hintUnlockLeftSeconds ?? 0) : 0);
       // Apply the cached draft synchronously so a warm/preloaded open paints the pending tiles
       // already on the board (no full-rack-then-jump). load() then refreshes in the background.
       applyDraft(cached.view, cached.draft ?? '');
@@ -264,6 +317,12 @@
         dict = m;
       });
     }
+    // A local (offline) game has no live stream: route the source's robot-reply events through the
+    // same app event hub the network stream feeds, so the event effect above reacts to
+    // opponent_moved / game_over identically.
+    if (isLocalGameId(id)) {
+      localUnsub = localSource.events(id, (e) => (app.lastEvent = e));
+    }
   });
 
   // Warm the game's dictionary for the local move preview once, when both the game and the
@@ -309,7 +368,11 @@
         // While composing, reload so a draft overlapping the new move is reconciled; otherwise apply
         // the move as a delta with no fetch.
         if (placement.pending.length > 0) void load();
-        else applyDelta(applyMoveDelta(cacheSnapshot(), { move: e.move, game: e.game, bagLen: e.bagLen }));
+        else {
+          applyDelta(applyMoveDelta(cacheSnapshot(), { move: e.move, game: e.game, bagLen: e.bagLen }));
+          // The robot just moved (vs_ai) → the human's turn begins with the full idle window.
+          if (view?.game.vsAi) armHintGate(HINT_GATE_MS / 1000);
+        }
       } else if (e.kind === 'your_turn' && e.gameId === id) {
         // The opponent_moved delta carries the new state; your_turn only confirms the turn. Refetch
         // only if we missed the move (our cached count trails the event's).
@@ -611,8 +674,13 @@
     // Flush a pending draft save so leaving mid-composition still persists it.
     if (draftSaveTimer) {
       clearTimeout(draftSaveTimer);
-      void gateway.draftSave(id, serializeDraft(rackIds, placement.pending)).catch(() => {});
+      void source.draftSave(id, serializeDraft(rackIds, placement.pending)).catch(() => {});
     }
+    localUnsub?.();
+    // Leaving a hotseat game re-locks the current seat, so returning from the lobby re-prompts its
+    // PIN. Read the id from the loaded view, NOT the `id` prop: a $props() value reads back undefined
+    // during Svelte teardown, and isLocalGameId(undefined) would throw and abort this cleanup.
+    if (view?.game.hotseat) localSource.relock(view.game.id);
   });
 
   function onCell(row: number, col: number) {
@@ -717,8 +785,8 @@
     // rapid placements do not pile up requests on a slow link.
     evalCtrl?.abort();
     evalCtrl = null;
-    // Off-turn the composition is position-only: no score preview or evaluate.
-    if (!isMyTurn) return;
+    // Off-turn (or a locked hotseat seat) the composition is position-only: no score preview.
+    if (!canMove) return;
     const sub = toSubmit(placement);
     if (!sub) return;
     // Instant on-device preview when the game's dictionary is warm; the network otherwise.
@@ -740,7 +808,7 @@
     evalCtrl = ctrl;
     previewTimer = setTimeout(async () => {
       try {
-        preview = await gateway.evaluate(id, sub.tiles, variant, ctrl.signal);
+        preview = await source.evaluate(id, sub.tiles, variant, ctrl.signal);
         notePreviewNetwork();
       } catch {
         /* best-effort (or aborted) */
@@ -776,12 +844,106 @@
     refreshRecent();
   }
 
+  // --- offline hotseat: seat unlock + host (referee) overrides -------------------
+  let unlockOpen = $state(false); // the current locked seat's owner enters their PIN to reveal the rack
+  // The host menu: 'pin' collects the master PIN, then 'menu' lists the overrides. hostPinEntered is
+  // the verified master PIN, reused to authorise the chosen action (the source re-checks it).
+  let hostMenuStep = $state<'closed' | 'pin' | 'menu'>('closed');
+  let hostPinEntered = $state('');
+  // The pending host action awaiting its confirm ("Skip X's turn?" etc.); null shows the menu list.
+  let hostConfirm = $state<{ action: 'skip' | 'resign' | 'terminate'; seat?: number; name?: string } | null>(null);
+  let hostDone = $state(false); // the transient success ✅ shown after an override
+
+  // hotseatName is the plain display name of a seat by index (hotseat seats are account-less local
+  // players, so no "you"/🤖 resolution is needed — unlike the seat-object seatName used elsewhere).
+  function hotseatName(i: number): string {
+    return view?.game.seats[i]?.displayName ?? '';
+  }
+
+  function startSkip(): void {
+    if (!view) return;
+    hostConfirm = { action: 'skip', seat: view.game.toMove, name: hotseatName(view.game.toMove) };
+  }
+
+  function flashDone(): void {
+    hostDone = true;
+    setTimeout(() => (hostDone = false), 1100);
+  }
+
+  // advanceHotseat re-points the screen at the next seat after a hotseat move: the source has advanced
+  // the turn and re-locked, so a fresh state gives the next seat's rack (empty while it is locked).
+  async function advanceHotseat(): Promise<void> {
+    const st = await source.gameState(id, false);
+    view = st;
+    rackIds = st.rack.map((_, i) => i);
+    placement = newPlacement(st.rack);
+    selected = null;
+    preview = null;
+    setCachedGame(id, st, moves, '');
+  }
+
+  // onUnlock verifies the current seat's PIN through the source (which reveals the rack on success)
+  // and applies the unlocked state; handed to the PIN pad as its verifier.
+  async function onUnlock(pin: string): Promise<boolean> {
+    try {
+      const st = await localSource.unlockSeat(id, pin);
+      view = st;
+      rackIds = st.rack.map((_, i) => i);
+      placement = newPlacement(st.rack);
+      selected = null;
+      return true;
+    } catch {
+      return false;
+    }
+  }
+
+  // verifyHost captures the entered master PIN (reused to authorise the chosen action) and checks it.
+  async function verifyHost(pin: string): Promise<boolean> {
+    hostPinEntered = pin;
+    return localSource.verifyHostPin(id, pin);
+  }
+
+  function hostConfirmText(c: { action: 'skip' | 'resign' | 'terminate'; name?: string }): string {
+    if (c.action === 'skip') return t('hotseat.askSkip', { name: c.name ?? '' });
+    if (c.action === 'resign') return t('hotseat.askExclude', { name: c.name ?? '' });
+    return t('hotseat.askTerminate');
+  }
+
+  async function runHostAction(): Promise<void> {
+    if (!hostConfirm) return;
+    const { action, seat } = hostConfirm;
+    hostConfirm = null;
+    hostMenuStep = 'closed';
+    busy = true;
+    try {
+      const st = await localSource.hostAction(id, hostPinEntered, action, seat);
+      if (st === null) {
+        navigate('/'); // terminated: the game is deleted, so return to the lobby
+        return;
+      }
+      view = st;
+      rackIds = st.rack.map((_, i) => i);
+      placement = newPlacement(st.rack);
+      selected = null;
+      preview = null;
+      moves = (await source.gameHistory(id)).moves; // a skip / resign added a journal move
+      setCachedGame(id, st, moves, '');
+      flashDone();
+    } catch (e) {
+      handleError(e);
+    } finally {
+      busy = false;
+      hostPinEntered = '';
+    }
+  }
+
   async function commit() {
     const sub = toSubmit(placement);
     if (!sub) return;
     busy = true;
     try {
-      applyMoveResult(await gateway.submitPlay(id, sub.tiles, variant));
+      applyMoveResult(await source.submitPlay(id, sub.tiles, variant));
+      if (view?.game.hotseat) await advanceHotseat();
       haptic('success');
       zoomed = false;
     } catch (e) {
@@ -800,7 +962,8 @@
   async function doPass() {
     busy = true;
     try {
-      applyMoveResult(await gateway.pass(id));
+      applyMoveResult(await source.pass(id));
+      if (view?.game.hotseat) await advanceHotseat();
     } catch (e) {
       handleError(e);
     } finally {
@@ -821,7 +984,7 @@
     resignOpen = false;
     busy = true;
     try {
-      applyMoveResult(await gateway.resign(id));
+      applyMoveResult(await source.resign(id));
       // Reveal the final board once the game is resigned: close the move-history drawer
       // (portrait — the landscape dock is unaffected) and zoom out if it was magnified.
       historyOpen = false;
@@ -833,8 +996,17 @@
     }
   }
   async function doHint() {
+    // vs_ai: the idle gate replaces the wallet. While it is still closed, a tap only explains when the
+    // hint unlocks (no wallet is ever spent) — matching the 🔒 badge. Measured fresh at tap time.
+    if (view?.game.vsAi) {
+      const remaining = hintGateRemainingMs(hintGateStart, gateLeftMs, performance.now());
+      if (remaining > 0) {
+        showToast(t('game.hintLockedIn', { n: hintLockMinutes(remaining) }), 'info');
+        return;
+      }
+    }
     try {
-      const h = await gateway.hint(id);
+      const h = await source.hint(id);
       if (h.move.tiles.length && view) {
         placement = placementFromHint(h.move.tiles, view.rack);
         // Scroll the (zoomed) board to the hint's placement rather than the top-left:
@@ -869,6 +1041,12 @@
       // The backend does not spend a hint when there is no move.
       if (e instanceof GatewayError && e.code === 'no_hint_available') {
         showToast(t('game.noHintOptions'), 'info');
+      } else if (e instanceof GatewayError && e.code === 'hint_locked') {
+        // The server-clock backstop refused a vs_ai hint the client thought was open (a rare client
+        // clock desync): re-sync the countdown from a fresh fetch and explain the gate.
+        await load();
+        const left = hintGateRemainingMs(hintGateStart, gateLeftMs, performance.now());
+        showToast(t('game.hintLockedIn', { n: hintLockMinutes(left || 60_000) }), 'info');
       } else {
         handleError(e);
       }
@@ -906,7 +1084,8 @@
     exchangeOpen = false;
     busy = true;
     try {
-      applyMoveResult(await gateway.exchange(id, tiles, variant));
+      applyMoveResult(await source.exchange(id, tiles, variant));
+      if (view?.game.hotseat) await advanceHotseat();
     } catch (e) {
       handleError(e);
     } finally {
@@ -928,7 +1107,15 @@
     if (!view) return '';
     const me = view.game.seats[view.seat];
     if (me?.isWinner) return t('game.won');
-    return view.game.seats.some((s) => s.isWinner) ? t('game.lost') : t('game.tied');
+    if (view.game.endReason === 'aborted') return t('game.tied'); // an abort is a draw for everyone
+    const myScore = me?.score ?? 0;
+    // A declared winner (incl. by resignation) that is not me, or anyone who scored higher → a loss.
+    if (view.game.seats.some((s) => s.isWinner) || view.game.seats.some((s) => !s.resigned && s.score > myScore)) {
+      return t('game.lost');
+    }
+    // No one above me and no declared winner: a tie for the lead is a (shared) win; only an
+    // all-level finish is a draw.
+    return view.game.seats.filter((s) => !s.resigned).every((s) => s.score === myScore) ? t('game.tied') : t('game.won');
   }
 
   // The finished-game export offers two formats — the GCG file and the server-rendered PNG
@@ -1244,8 +1431,9 @@
   // (not the still-empty seat of an open game) who is not yet a friend (an already-requested
   // opponent still shows it, but disabled).
   function canAddFriend(s: { accountId: string; seat: number }): boolean {
-    // Never offer add-friend against an AI opponent, an existing friend, or a blocked player.
-    if (view?.game.vsAi) return false;
+    // Never offer add-friend against an AI opponent, an existing friend, or a blocked player — nor in
+    // a local (offline) game, whose seats are account-less: vs_ai, and hotseat's synthetic seat ids.
+    if (view?.game.vsAi || isLocalGameId(id)) return false;
     return (
       !!s.accountId &&
       !app.profile?.isGuest &&
@@ -1259,7 +1447,7 @@
   // may still be blocked (the block overrides the friendship), so it omits the friend exclusion.
   // An already-blocked opponent hides it (both controls go, and the name is struck).
   function canBlock(s: { accountId: string; seat: number }): boolean {
-    if (view?.game.vsAi) return false;
+    if (view?.game.vsAi || isLocalGameId(id)) return false;
     return !!s.accountId && !app.profile?.isGuest && s.accountId !== app.session?.userId && !seatBlocked(s);
   }
 </script>
@@ -1317,7 +1505,7 @@
       {#if badge}<span class="unread-dot sbadge-dot" class:nudge={badge === 'nudge'}></span>{/if}
       {#each view.game.seats as s (s.seat)}
         <div class="seat" class:turn={view.game.toMove === s.seat && !gameOver} class:win={s.isWinner}>
-          <div class="nm" class:struck={seatBlocked(s)}>{seatName(s)}</div>
+          <div class="nm" class:struck={seatBlocked(s)}>{#if gameOver && view.game.hotseat}<span class="medal" aria-hidden="true">{seatMedal(view.game, s.seat)}</span>{/if}{seatName(s)}</div>
           <div class="sc" class:blockprompt={blockConfirm[s.seat]}>
             {#if blockConfirm[s.seat]}{t('game.blockShort')}{:else if addConfirm[s.seat]}{t('game.addFriendShort')}{:else}{s.score}{/if}
           </div>
@@ -1361,13 +1549,18 @@
         {:else}
           <button class="hicon" onclick={onExportClick} aria-label={t('game.exportGcg')}>📤</button>
         {/if}
+      {:else if view.game.hotseat}
+        <!-- Hotseat resign is a host (referee) action, not self-serve; keep the slot empty. -->
+        <span aria-hidden="true"></span>
       {:else}
         <button class="hicon" onclick={onResignClick} disabled={waitingForOpponent} aria-label={t('game.dropGame')}>🏁</button>
       {/if}
       {#if !view.game.multipleWordsPerTurn}<span class="oneword-label">{t('game.oneWordRule')}</span>{/if}
-      <!-- A finished AI game has no comms at all (no chat, and the dictionary closes with the
-           game), so the entry is dropped; an active AI game keeps it (it opens the dictionary). -->
-      {#if !(gameOver && view.game.vsAi)}
+      <!-- The comms entry opens Chat + the word Dictionary. A local game (vs_ai or hotseat) has no
+           chat, so its hub is Dictionary-only (CommsHub), and once finished the dictionary closes too
+           — so drop the entry only when a local game is finished; an active local game keeps it for
+           the Dictionary. An online game always keeps it (chat outlives the game). -->
+      {#if !(gameOver && (view.game.vsAi || view.game.hotseat))}
         <button class="hicon" onclick={() => navigate(`/game/${id}/chat`)} aria-label={t('game.chat')}>
           {#key chatBlink}<span class="chat-ico" class:blink={chatBlink > 0 && !app.reduceMotion}>💬</span>{/key}
         </button>
@@ -1438,9 +1631,12 @@
     <div class="status">
       <span>{view.bagLen === 0 ? t('game.bagEmpty') : t('game.bag', { n: view.bagLen })}</span>
       {#if gameOver}
-        <strong class="over">{resultText()}</strong>
+        <!-- A hotseat game shows its result as per-seat medals on the plaques (below), not a
+             viewer-centric "you won/lost" — with 2-4 local players there is no single "you". A vs_ai
+             game keeps the "you won/lost" text (one human). -->
+        {#if !view.game.hotseat}<strong class="over">{resultText()}</strong>{/if}
       {:else if placement.pending.length === 0}
-        <span class="turn-ind">{isMyTurn ? t('game.yourTurn') : turnLabel()}</span>
+        <span class="turn-ind">{view.game.hotseat ? t('hotseat.turnOf', { name: hotseatName(view.game.toMove) }) : isMyTurn ? t('game.yourTurn') : turnLabel()}</span>
       {/if}
       <span class="scores">
         {#if recallOverRack}{:else if preview}{preview.legal ? t('game.previewWords', { words: preview.words.join(', '), n: preview.score }) : t('game.previewIllegal')}{/if}
@@ -1454,36 +1650,58 @@
        a finished game shows the final rack greyed out and the controls disabled. -->
   <div class="rack-row" class:inert={gameOver} data-coach="game-rack">
     <div class="rack-wrap">
-      <Rack
-        slots={rackSlots}
-        {variant}
-        {selected}
-        {landscape}
-        shuffling={shuffling && !app.reduceMotion}
-        draggingId={reorderDragId}
-        dropIndex={reorderTo}
-        ondown={onRackDown}
-      />
+      {#if locked}
+        <!-- A PIN-locked hotseat seat: the rack is withheld until its owner unlocks it. The board
+             above stays visible; only this tray is gated. -->
+        <button class="unlock" onclick={() => (unlockOpen = true)}>🔒 {t('hotseat.unlock')}</button>
+      {:else}
+        <Rack
+          slots={rackSlots}
+          {variant}
+          {selected}
+          {landscape}
+          shuffling={shuffling && !app.reduceMotion}
+          draggingId={reorderDragId}
+          dropIndex={reorderTo}
+          ondown={onRackDown}
+        />
+      {/if}
     </div>
     {#if !gameOver && placement.pending.length > 0 && !recallOverRack}
-      <button class="make" onclick={commit} disabled={busy || !isMyTurn || !connection.online || !preview?.legal} aria-label={t('game.makeMove')}>✅</button>
+      <button class="make" onclick={commit} disabled={busy || !canMove || !netReady || !preview?.legal} aria-label={t('game.makeMove')}>✅</button>
     {/if}
   </div>
 {/snippet}
 
 {#snippet controlButtons()}
-  <button class="tab" disabled={busy || !isMyTurn || !connection.online} onclick={openExchange}>
+  <button class="tab" disabled={busy || !canMove || !netReady} onclick={openExchange}>
     <span class="sq" data-coach="game-turn">🔄</span><span class="lbl">{t('game.draw')}</span>
   </button>
-  <TapConfirm
-    triggerClass="tab"
-    label={t('game.hint')}
-    disabled={busy || !isMyTurn || !connection.online || hintCount <= 0}
-    onconfirm={doHint}
-  >
-    <span class="sq" data-coach="game-hints">🛟{#if hintCount > 0}<span class="badge">{hintCount}</span>{/if}</span>
-    <span class="lbl">{t('game.hint')}</span>
-  </TapConfirm>
+  {#if view?.game.hotseat}
+    <!-- Hotseat: no hints. The freed slot becomes the host (referee) button — always available
+         (even on a locked seat: the host may skip a player who forgot their PIN). -->
+    <button class="tab" disabled={busy || gameOver} onclick={() => (hostMenuStep = 'pin')}>
+      <span class="sq">🔐</span><span class="lbl">{t('hotseat.host')}</span>
+    </button>
+  {:else if view?.game.vsAi}
+    <!-- vs_ai hints are unlimited and wallet-free, so no confirm and no count. A 🔒 badge marks the
+         idle gate while it is closed; tapping then only explains when it opens (doHint), and the lock
+         lifts live at the unlock moment. -->
+    <button class="tab" disabled={busy || !isMyTurn || !netReady} onclick={doHint}>
+      <span class="sq" data-coach="game-hints">🛟{#if hintGated}<span class="lock" aria-hidden="true">🔒</span>{/if}</span>
+      <span class="lbl">{t('game.hint')}</span>
+    </button>
+  {:else}
+    <TapConfirm
+      triggerClass="tab"
+      label={t('game.hint')}
+      disabled={busy || !isMyTurn || !netReady || hintCount <= 0}
+      onconfirm={doHint}
+    >
+      <span class="sq" data-coach="game-hints">🛟{#if hintCount > 0}<span class="badge">{hintCount}</span>{/if}</span>
+      <span class="lbl">{t('game.hint')}</span>
+    </TapConfirm>
+  {/if}
   {#if placement.pending.length > 0}
     <button class="tab" disabled={busy} onclick={resetPlacement}>
       <span class="sq">↩️</span><span class="lbl">{t('game.reset')}</span>
@@ -1536,11 +1754,60 @@
   <Modal title={t('game.confirmResign')} onclose={() => (resignOpen = false)}>
     <div class="confirm-row">
       <button class="cancel" onclick={() => (resignOpen = false)}>{t('common.cancel')}</button>
-      <button class="danger" onclick={doResign} disabled={!connection.online}>{t('game.dropGame')}</button>
+      <button class="danger" onclick={doResign} disabled={!netReady}>{t('game.dropGame')}</button>
     </div>
   </Modal>
 {/if}
 
+<!-- Offline hotseat: unlock the current seat's rack. -->
+{#if unlockOpen && view}
+  <PinPad
+    mode="verify"
+    title={t('hotseat.unlockTitle', { name: hotseatName(view.game.toMove) })}
+    verify={onUnlock}
+    onclose={() => (unlockOpen = false)}
+    onresult={() => (unlockOpen = false)}
+  />
+{/if}
+
+<!-- Offline hotseat: the host (referee) enters the master PIN, then picks an override. -->
+{#if hostMenuStep === 'pin'}
+  <PinPad
+    mode="verify"
+    title={t('hotseat.host')}
+    verify={verifyHost}
+    onclose={() => (hostMenuStep = 'closed')}
+    onresult={() => (hostMenuStep = 'menu')}
+  />
+{/if}
+{#if hostMenuStep === 'menu' && view}
+  <Modal title={t('hotseat.host')} onclose={() => { hostMenuStep = 'closed'; hostConfirm = null; }}>
+    {#if hostConfirm}
+      <p class="host-q">{hostConfirmText(hostConfirm)}</p>
+      <div class="confirm-row">
+        <button class="cancel" onclick={() => (hostConfirm = null)}>{t('common.cancel')}</button>
+        <button class="danger" onclick={runHostAction}>{t('common.ok')}</button>
+      </div>
+    {:else}
+      <div class="host-menu">
+        <button class="host-act" onclick={startSkip}>
+          {t('hotseat.skip')}
+        </button>
+        <div class="host-sub">{t('hotseat.exclude')}</div>
+        {#each view.game.seats as s (s.seat)}
+          <button class="host-seat" onclick={() => (hostConfirm = { action: 'resign', seat: s.seat, name: s.displayName })}>
+            {s.displayName}
+          </button>
+        {/each}
+        <button class="host-act danger" onclick={() => (hostConfirm = { action: 'terminate' })}>{t('hotseat.terminate')}</button>
+      </div>
+    {/if}
+  </Modal>
+{/if}
+{#if hostDone}
+  <div class="host-done" aria-hidden="true">✅</div>
+{/if}
+
 {#if exportOpen}
   <Modal title={t('game.exportGcg')} onclose={() => (exportOpen = false)}>
     <div class="export-opts">
@@ -1548,7 +1815,7 @@
         <button
           class="confirm"
           onclick={() => { exportOpen = false; void exportArtifact('png'); }}
-          disabled={!connection.online}
+          disabled={!netReady}
         >
           {t('game.exportImageOpt')}
         </button>
@@ -1556,7 +1823,7 @@
       <button
         class={exportImageAvailable ? 'export-alt' : 'confirm'}
         onclick={() => { exportOpen = false; void exportArtifact('gcg'); }}
-        disabled={!connection.online}
+        disabled={!netReady}
       >
         {t('game.exportGcgOpt')}
       </button>
@@ -1610,6 +1877,10 @@
     overflow: hidden;
     text-overflow: ellipsis;
   }
+  /* The finished-game place medal on a local (offline) seat plaque, left of the name. */
+  .medal {
+    margin-right: 3px;
+  }
   .sc {
     font-weight: 700;
     font-variant-numeric: tabular-nums;
@@ -2031,4 +2302,76 @@
   .scoreboard.flat {
     cursor: default;
   }
+  /* The vs_ai hint's idle lock: a small 🔒 at the icon-square corner (the .sq is positioned by the
+     shared TabBar rule). No count pill — the hint is unlimited; the lock alone marks the gate. */
+  .sq .lock {
+    position: absolute;
+    top: -4px;
+    right: -4px;
+    font-size: 0.62rem;
+    line-height: 1;
+  }
+  /* --- offline hotseat --- */
+  /* The locked-seat rack overlay: fills the rack tray with an "unlock" button, the board above
+     stays visible. */
+  .unlock {
+    width: 100%;
+    height: 100%;
+    min-height: 44px;
+    border: 1px dashed var(--border);
+    border-radius: var(--radius-sm);
+    background: var(--surface);
+    color: var(--text);
+    font-weight: 600;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    gap: 8px;
+  }
+  .host-menu {
+    display: flex;
+    flex-direction: column;
+    gap: 8px;
+  }
+  .host-act,
+  .host-seat {
+    padding: 12px;
+    border: 1px solid var(--border);
+    border-radius: var(--radius-sm);
+    background: var(--surface);
+    color: var(--text);
+    font-weight: 600;
+    text-align: left;
+  }
+  .host-act.danger {
+    border-color: var(--danger);
+    color: var(--danger);
+  }
+  .host-sub {
+    font-size: 0.8rem;
+    color: var(--text-muted);
+    margin-top: 4px;
+  }
+  .host-q {
+    margin: 0 0 12px;
+    font-weight: 600;
+  }
+  /* The transient success tick after a host override — a centred ✅ that fades out on a timer. */
+  .host-done {
+    position: fixed;
+    inset: 0;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    font-size: 4rem;
+    z-index: 50;
+    pointer-events: none;
+    animation: host-done-fade 1.1s ease forwards;
+  }
+  @keyframes host-done-fade {
+    0% { opacity: 0; transform: scale(0.7); }
+    25% { opacity: 1; transform: scale(1); }
+    75% { opacity: 1; transform: scale(1); }
+    100% { opacity: 0; transform: scale(1); }
+  }
 </style>

ui/src/gen/fbs/scrabblefb.ts

@@ -17,6 +17,7 @@ export { ChatPostRequest } from './scrabblefb/chat-post-request.js';
 export { CheckWordRequest } from './scrabblefb/check-word-request.js';
 export { ComplaintRequest } from './scrabblefb/complaint-request.js';
 export { CreateInvitationRequest } from './scrabblefb/create-invitation-request.js';
+export { DictVersion } from './scrabblefb/dict-version.js';
 export { DraftRequest } from './scrabblefb/draft-request.js';
 export { DraftView } from './scrabblefb/draft-view.js';
 export { EmailConfirmLinkRequest } from './scrabblefb/email-confirm-link-request.js';

ui/src/gen/fbs/scrabblefb/dict-version.ts

@@ -0,0 +1,60 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+import * as flatbuffers from 'flatbuffers';
+
+export class DictVersion {
+  bb: flatbuffers.ByteBuffer|null = null;
+  bb_pos = 0;
+  __init(i:number, bb:flatbuffers.ByteBuffer):DictVersion {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+}
+
+static getRootAsDictVersion(bb:flatbuffers.ByteBuffer, obj?:DictVersion):DictVersion {
+  return (obj || new DictVersion()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+static getSizePrefixedRootAsDictVersion(bb:flatbuffers.ByteBuffer, obj?:DictVersion):DictVersion {
+  bb.setPosition(bb.position() + flatbuffers.SIZE_PREFIX_LENGTH);
+  return (obj || new DictVersion()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+variant():string|null
+variant(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+variant(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 4);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+version():string|null
+version(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+version(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 6);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+static startDictVersion(builder:flatbuffers.Builder) {
+  builder.startObject(2);
+}
+
+static addVariant(builder:flatbuffers.Builder, variantOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(0, variantOffset, 0);
+}
+
+static addVersion(builder:flatbuffers.Builder, versionOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(1, versionOffset, 0);
+}
+
+static endDictVersion(builder:flatbuffers.Builder):flatbuffers.Offset {
+  const offset = builder.endObject();
+  return offset;
+}
+
+static createDictVersion(builder:flatbuffers.Builder, variantOffset:flatbuffers.Offset, versionOffset:flatbuffers.Offset):flatbuffers.Offset {
+  DictVersion.startDictVersion(builder);
+  DictVersion.addVariant(builder, variantOffset);
+  DictVersion.addVersion(builder, versionOffset);
+  return DictVersion.endDictVersion(builder);
+}
+}

ui/src/gen/fbs/scrabblefb/profile.ts

@@ -3,6 +3,7 @@
 import * as flatbuffers from 'flatbuffers';
 
 import { BannerInfo } from '../scrabblefb/banner-info.js';
+import { DictVersion } from '../scrabblefb/dict-version.js';
 
 
 export class Profile {
@@ -124,8 +125,18 @@ vkLinked():boolean {
   return offset ? !!this.bb!.readInt8(this.bb_pos + offset) : false;
 }
 
+dictVersions(index: number, obj?:DictVersion):DictVersion|null {
+  const offset = this.bb!.__offset(this.bb_pos, 36);
+  return offset ? (obj || new DictVersion()).__init(this.bb!.__indirect(this.bb!.__vector(this.bb_pos + offset) + index * 4), this.bb!) : null;
+}
+
+dictVersionsLength():number {
+  const offset = this.bb!.__offset(this.bb_pos, 36);
+  return offset ? this.bb!.__vector_len(this.bb_pos + offset) : 0;
+}
+
 static startProfile(builder:flatbuffers.Builder) {
-  builder.startObject(16);
+  builder.startObject(17);
 }
 
 static addUserId(builder:flatbuffers.Builder, userIdOffset:flatbuffers.Offset) {
@@ -204,6 +215,22 @@ static addVkLinked(builder:flatbuffers.Builder, vkLinked:boolean) {
   builder.addFieldInt8(15, +vkLinked, +false);
 }
 
+static addDictVersions(builder:flatbuffers.Builder, dictVersionsOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(16, dictVersionsOffset, 0);
+}
+
+static createDictVersionsVector(builder:flatbuffers.Builder, data:flatbuffers.Offset[]):flatbuffers.Offset {
+  builder.startVector(4, data.length, 4);
+  for (let i = data.length - 1; i >= 0; i--) {
+    builder.addOffset(data[i]!);
+  }
+  return builder.endVector();
+}
+
+static startDictVersionsVector(builder:flatbuffers.Builder, numElems:number) {
+  builder.startVector(4, numElems, 4);
+}
+
 static endProfile(builder:flatbuffers.Builder):flatbuffers.Offset {
   const offset = builder.endObject();
   return offset;

ui/src/gen/fbs/scrabblefb/state-view.ts

@@ -74,8 +74,13 @@ walletBalance():number {
   return offset ? this.bb!.readInt32(this.bb_pos + offset) : 0;
 }
 
+hintUnlockLeftSeconds():number {
+  const offset = this.bb!.__offset(this.bb_pos, 18);
+  return offset ? this.bb!.readInt32(this.bb_pos + offset) : 0;
+}
+
 static startStateView(builder:flatbuffers.Builder) {
-  builder.startObject(7);
+  builder.startObject(8);
 }
 
 static addGame(builder:flatbuffers.Builder, gameOffset:flatbuffers.Offset) {
@@ -130,12 +135,16 @@ static addWalletBalance(builder:flatbuffers.Builder, walletBalance:number) {
   builder.addFieldInt32(6, walletBalance, 0);
 }
 
+static addHintUnlockLeftSeconds(builder:flatbuffers.Builder, hintUnlockLeftSeconds:number) {
+  builder.addFieldInt32(7, hintUnlockLeftSeconds, 0);
+}
+
 static endStateView(builder:flatbuffers.Builder):flatbuffers.Offset {
   const offset = builder.endObject();
   return offset;
 }
 
-static createStateView(builder:flatbuffers.Builder, gameOffset:flatbuffers.Offset, seat:number, rackOffset:flatbuffers.Offset, bagLen:number, hintsRemaining:number, alphabetOffset:flatbuffers.Offset, walletBalance:number):flatbuffers.Offset {
+static createStateView(builder:flatbuffers.Builder, gameOffset:flatbuffers.Offset, seat:number, rackOffset:flatbuffers.Offset, bagLen:number, hintsRemaining:number, alphabetOffset:flatbuffers.Offset, walletBalance:number, hintUnlockLeftSeconds:number):flatbuffers.Offset {
   StateView.startStateView(builder);
   StateView.addGame(builder, gameOffset);
   StateView.addSeat(builder, seat);
@@ -144,6 +153,7 @@ static createStateView(builder:flatbuffers.Builder, gameOffset:flatbuffers.Offse
   StateView.addHintsRemaining(builder, hintsRemaining);
   StateView.addAlphabet(builder, alphabetOffset);
   StateView.addWalletBalance(builder, walletBalance);
+  StateView.addHintUnlockLeftSeconds(builder, hintUnlockLeftSeconds);
   return StateView.endStateView(builder);
 }
 }

ui/src/lib/app.svelte.ts

@@ -43,6 +43,9 @@ import { parseStartParam } from './deeplink';
 import {
   clearOnboarding,
   clearSession,
+  clearProfile,
+  loadProfile,
+  saveProfile,
   loadOnboarding,
   loadPrefs,
   loadSession,
@@ -52,7 +55,9 @@ import {
   savePrefs,
 } from './session';
 import type { CoachSeries } from './coachmark';
-import { connection, reportOffline, reportOnline, resetConnection } from './connection.svelte';
+import { connection, reportOffline, reportOnline, resetConnection, checkReachable } from './connection.svelte';
+import { offlineMode, setOfflineMode } from './offline.svelte';
+import { shouldBootOffline } from './offline';
 import { isConnectionCode } from './retry';
 import { clearGameCache, getCachedGame, setCachedGame } from './gamecache';
 import { advanceCached } from './gamedelta';
@@ -73,6 +78,10 @@ export const app = $state<{
    *  backend was down during a deploy). App.svelte then renders the boot-error retry screen
    *  instead of the web login — a Mini App has no manual sign-in to fall back to. */
   bootError: boolean;
+  /** True while the cold-start "no connection — go offline?" dialog is up (the reachability check
+   *  timed out with the network interface reportedly online). App.svelte renders it over the splash;
+   *  bootstrap awaits the choice via resolveOfflinePrompt. */
+  offlinePrompt: boolean;
   /** On the dedicated /telegram/ entry, set to a privacy-safe diagnostic snapshot when a Mini App
    *  launch carried no sign-in data (empty initData). App.svelte then renders the compact
    *  launch-error screen (screens/TelegramLaunchError) — a shareable probe for why Telegram
@@ -143,6 +152,7 @@ export const app = $state<{
 }>({
   ready: false,
   bootError: false,
+  offlinePrompt: false,
   launchError: null,
   debugOpen: false,
   lobbyReady: false,
@@ -294,7 +304,9 @@ export function handleError(err: unknown): void {
     void enterBlocked();
     return;
   }
-  if (isConnectionCode(code) || !connection.online) return;
+  // A blocked call in offline mode ('offline', the transport kill switch) is expected, not an error
+  // to surface — the offline chrome already signals the state; never a red toast.
+  if (isConnectionCode(code) || code === 'offline' || !connection.online) return;
   haptic('error');
   showToast(t(code ? errorKey(code) : 'error.generic'), 'error');
 }
@@ -460,6 +472,7 @@ export async function refreshProfile(): Promise<void> {
   if (!app.session) return;
   try {
     app.profile = await gateway.profileGet();
+    void saveProfile($state.snapshot(app.profile)); // keep the offline-boot cache fresh (plain snapshot)
   } catch {
     // Best-effort; the banner just stays as it was until the next fetch.
   }
@@ -517,6 +530,11 @@ async function adoptSession(s: Session): Promise<void> {
   await saveSession(s);
   try {
     app.profile = await gateway.profileGet();
+    // Persist the profile so a later offline cold start can launch from it (its variant
+    // preferences, dictionary versions and display name) without a network fetch. Snapshot to a
+    // plain object first — the reactive $state proxy is not structured-cloneable, so it would fail
+    // the IndexedDB write and fall back to a localStorage entry that loadProfile never reads.
+    void saveProfile($state.snapshot(app.profile));
     // The live interface language follows the device — the explicit local choice (saved in
     // prefs) or the system guess made at bootstrap — and is no longer overridden from the
     // account here: the Telegram bot a user signs in through must not dictate the UI, so a
@@ -540,6 +558,74 @@ async function adoptSession(s: Session): Promise<void> {
   void refreshNotifications();
 }
 
+// The cold-start "no connection — go offline?" dialog. bootstrap raises it and awaits the choice
+// here; App.svelte's dialog buttons call resolveOfflinePrompt.
+const BOOT_REACHABILITY_TIMEOUT_MS = 3000;
+let offlinePromptResolve: ((goOffline: boolean) => void) | null = null;
+
+/** resolveOfflinePrompt answers the cold-start "no connection — go offline?" dialog (App.svelte). */
+export function resolveOfflinePrompt(goOffline: boolean): void {
+  app.offlinePrompt = false;
+  const resolve = offlinePromptResolve;
+  offlinePromptResolve = null;
+  resolve?.(goOffline);
+}
+
+/** promptOfflineChoice raises the dialog and resolves to the player's choice (true = go offline). */
+function promptOfflineChoice(): Promise<boolean> {
+  app.offlinePrompt = true;
+  return new Promise<boolean>((resolve) => {
+    offlinePromptResolve = resolve;
+  });
+}
+
+/**
+ * initNetworkReactivity reacts to mid-session network changes (e.g. the player toggling flight mode):
+ * losing the network interface enters offline mode automatically (session-only); regaining it
+ * verifies the gateway is really reachable (an interface being up does not guarantee it) and returns
+ * to online — but only if the offline was auto. A deliberate offline (the Settings toggle or the
+ * cold-start dialog) is left as the player's choice. These are passive OS events — no polling, no
+ * battery cost. Web-only and skipped in the mock (the e2e drives connectivity directly).
+ */
+// While in auto-offline, poll for the network to return so the app comes back online — robust to the
+// unreliable `online` event (which often does not fire in an installed PWA). Each tick is cheap: it
+// reads navigator.onLine (no radio) and only hits the network (a reachability check) when the
+// interface is actually up, so while flight mode is on it costs nothing. The poll runs ONLY in
+// auto-offline (a deliberate offline is the player's choice) and stops on returning online.
+let recoveryTimer: ReturnType<typeof setTimeout> | null = null;
+export function scheduleRecovery(delayMs: number): void {
+  if (recoveryTimer) {
+    clearTimeout(recoveryTimer);
+    recoveryTimer = null;
+  }
+  if (typeof window === 'undefined' || !offlineMode.active || !offlineMode.auto) return;
+  recoveryTimer = setTimeout(async () => {
+    recoveryTimer = null;
+    if (!offlineMode.active || !offlineMode.auto) return;
+    const interfaceUp = typeof navigator === 'undefined' || navigator.onLine;
+    if (interfaceUp && (await checkReachable(BOOT_REACHABILITY_TIMEOUT_MS))) {
+      if (offlineMode.active && offlineMode.auto) setOfflineMode(false);
+      return;
+    }
+    scheduleRecovery(4000);
+  }, delayMs);
+}
+
+export function initNetworkReactivity(): void {
+  if (typeof window === 'undefined' || import.meta.env.MODE === 'mock') return;
+  window.addEventListener('offline', () => {
+    if (!offlineMode.active) {
+      setOfflineMode(true, false); // auto (session)
+      scheduleRecovery(4000); // poll for the network to return
+    }
+  });
+  // The online event, when it fires, just kicks an immediate reachability check; the poll above is
+  // the reliable fallback for platforms where it does not fire.
+  window.addEventListener('online', () => {
+    if (offlineMode.active && offlineMode.auto) scheduleRecovery(0);
+  });
+}
+
 /**
  * applyLinkResult applies a completed account link or merge: it adopts a
  * switched session (a guest initiator whose durable counterpart won, so the active
@@ -639,17 +725,37 @@ function syncTelegramSafeArea(): void {
   root.classList.toggle('tg-fullscreen', top > 0);
 }
 
+// The soft-keyboard height threshold (px) that distinguishes an open keyboard from browser chrome
+// (an address bar shrinks the visual viewport by far less), used to gate the focus-into-view scroll.
+const KEYBOARD_MIN_PX = 120;
+
 /**
- * syncViewportHeight mirrors the visual-viewport height into the --vvh CSS var so a screen can
- * fit the visible area above an open soft keyboard (iOS does not shrink dvh for the keyboard).
- * On a screen whose input sits at the bottom (chat, word-check) this keeps the input visible
- * without the page scrolling, so the layout no longer jumps when the keyboard appears.
+ * syncViewport mirrors the visual viewport into CSS vars so the pinned app-shell (app.css
+ * `html.app-shell body`) both FITS (`--vvh`) and FOLLOWS (`--vv-top`) the visible area above the soft
+ * keyboard. iOS Safari / WKWebView does not shrink the layout viewport for the keyboard (Android
+ * Chrome does); instead the visual viewport shrinks AND offsets down to reveal the focused field, and
+ * those values do not always cleanly revert. Tracking only the height left the top-anchored shell
+ * misaligned on iOS — empty space below the content, worst on a repeat focus; tracking offsetTop too
+ * keeps the shell on the visible area on every platform. On the keyboard-OPEN transition it also
+ * scrolls the focused field into view, since iOS does not reliably scroll a pinned document to it.
  */
-function syncViewportHeight(): void {
+let keyboardOpen = false;
+function syncViewport(): void {
   if (typeof document === 'undefined') return;
-  const vv = typeof window !== 'undefined' ? window.visualViewport : null;
-  const h = vv ? vv.height : typeof window !== 'undefined' ? window.innerHeight : 0;
+  const win = typeof window !== 'undefined' ? window : null;
+  const vv = win ? win.visualViewport : null;
+  const h = vv ? vv.height : win ? win.innerHeight : 0;
+  const top = vv ? vv.offsetTop : 0;
   if (h > 0) document.documentElement.style.setProperty('--vvh', `${h}px`);
+  document.documentElement.style.setProperty('--vv-top', `${top}px`);
+  const open = !!vv && !!win && win.innerHeight - h > KEYBOARD_MIN_PX;
+  if (open && !keyboardOpen) {
+    const el = document.activeElement;
+    if (el instanceof HTMLElement && (el.tagName === 'INPUT' || el.tagName === 'TEXTAREA')) {
+      requestAnimationFrame(() => el.scrollIntoView({ block: 'center' }));
+    }
+  }
+  keyboardOpen = open;
 }
 
 /**
@@ -709,11 +815,23 @@ export async function bootstrap(): Promise<void> {
     setLocale(guess);
   }
 
-  // Track the visual-viewport height so screens fit above an open soft keyboard (--vvh).
-  syncViewportHeight();
+  // Track the visual viewport (height + offset) so screens fit and follow the visible area above an
+  // open soft keyboard (--vvh / --vv-top). Both resize AND scroll fire on iOS when the keyboard moves
+  // the visual viewport.
+  syncViewport();
   if (typeof window !== 'undefined' && window.visualViewport) {
-    window.visualViewport.addEventListener('resize', syncViewportHeight);
-    window.visualViewport.addEventListener('scroll', syncViewportHeight);
+    window.visualViewport.addEventListener('resize', syncViewport);
+    window.visualViewport.addEventListener('scroll', syncViewport);
+  }
+
+  // Enter on a single-line <input> dismisses the soft keyboard (blur): the keyboard's default
+  // return/"Go" key otherwise does nothing on a bare input, which reads as stuck. A <textarea> (the
+  // feedback form) is excluded so Enter still inserts a newline; a form's own Enter→submit still
+  // fires first (this listener is on the document, so it runs after the field's own handler).
+  if (typeof document !== 'undefined') {
+    document.addEventListener('keydown', (e) => {
+      if (e.key === 'Enter' && e.target instanceof HTMLInputElement) e.target.blur();
+    });
   }
 
   // Load the Telegram Mini App SDK dynamically, with a timeout, on a Telegram entry — it is no
@@ -789,12 +907,61 @@ export async function bootstrap(): Promise<void> {
   // worker so the app is installable — Chromium needs a registered SW, notably on Android. Web-only
   // and skipped in the mock build; see lib/pwa.svelte.
   registerServiceWorker();
+  // React to mid-session network changes (e.g. flight mode) for the rest of the session.
+  initNetworkReactivity();
+
+  // Deliberate offline mode carried over from a prior session: with no network the session adoption
+  // + profile fetch below would hang the splash, so skip them and launch straight from the cached
+  // session + profile into the offline lobby. Without a cached profile (e.g. storage cleared) fall
+  // through to the normal online flow but KEEP the sticky flag — the mode is the player's choice, and
+  // an online boot re-persists the profile so the next launch goes offline. (A truly offline launch
+  // with no cached profile is unreachable: enabling offline requires a prior online session.)
+  if (offlineMode.active) {
+    const [offlineSession, offlineProfile] = await Promise.all([loadSession(), loadProfile()]);
+    if (shouldBootOffline({ offlineActive: true, hasSession: !!offlineSession, hasProfile: !!offlineProfile })) {
+      gateway.setToken(offlineSession!.token);
+      app.session = offlineSession!;
+      app.profile = offlineProfile!;
+      if (router.route.name === 'login' || router.route.name === 'confirm') navigate('/');
+      app.ready = true;
+      return;
+    }
+  }
 
   const saved = await loadSession();
   // A VK ID web-link callback (?code&device_id&state) rides the URL after the redirect back
   // from VK; capture and clear it here (it needs the restored session to link against).
   const vkcb = pendingVKLink();
   if (saved) {
+    // Cold-start network auto-detect (deliberate offline is handled above). With a cached profile to
+    // fall back on and no pending VK-link, do not hang on adoptSession's retrying profile fetch when
+    // the network is down: a device with no network interface goes offline for the session (no
+    // dialog); an interface that is up but cannot reach the gateway within a short window asks the
+    // player. Web-only reaches here (the Mini-App branches returned above), so isStandalone gates it.
+    const cachedProfile = await loadProfile();
+    const canOffline = !!cachedProfile && !vkcb && isStandalone() && !!cachedProfile.email;
+    if (canOffline) {
+      const interfaceOffline = typeof navigator !== 'undefined' && navigator.onLine === false;
+      gateway.setToken(saved.token);
+      const reachable = interfaceOffline ? false : await checkReachable(BOOT_REACHABILITY_TIMEOUT_MS);
+      if (!reachable) {
+        // No network interface → go offline for the session (no dialog); interface up but the
+        // gateway is unreachable → ambiguous, so ask.
+        const goOffline = interfaceOffline ? true : await promptOfflineChoice();
+        if (goOffline) {
+          // A deliberate dialog choice is sticky; an auto (no-interface) offline is session-only.
+          setOfflineMode(true, !interfaceOffline);
+          if (interfaceOffline) scheduleRecovery(4000); // auto-offline: poll for the network to return
+          app.session = saved;
+          app.profile = cachedProfile;
+          if (router.route.name === 'login' || router.route.name === 'confirm') navigate('/');
+          app.ready = true;
+          return;
+        }
+        // "Нет" — keep trying online: fall through to adoptSession (it retries; the connection
+        // watcher shows "Connecting…").
+      }
+    }
     await adoptSession(saved);
     if (vkcb) {
       // The full-page redirect lost the in-app route, so hand the callback to Profile, which
@@ -1023,6 +1190,7 @@ export async function logout(): Promise<void> {
   app.splashDone = false;
   gateway.setToken(null);
   await clearSession();
+  await clearProfile();
   app.session = null;
   app.profile = null;
   navigate('/login');
@@ -1174,4 +1342,11 @@ if (import.meta.env.MODE === 'mock' && typeof window !== 'undefined') {
     closeStream();
     app.blocked = { blocked: true, permanent: true, until: '', reason: '', ...b };
   };
+  // Expose the router so the e2e can assert navigate() updates the route synchronously (no
+  // hashchange lag): a route that trailed the hash for a frame let bootstrap's `app.ready` flip
+  // render the previous route under the new screen (the empty-hash lobby flashing under login).
+  (window as unknown as { __router?: { navigate(p: string): void; route(): string } }).__router = {
+    navigate,
+    route: () => router.route.name,
+  };
 }

ui/src/lib/codec.test.ts

@@ -712,6 +712,28 @@ describe('codec', () => {
     expect(decodeProfile(b.asUint8Array()).variantPreferences).toEqual(['erudit_ru', 'scrabble_en']);
   });
 
+  it('decodes the profile dictionary versions into a per-variant map', () => {
+    const b = new Builder(128);
+    const uid = b.createString('u-1');
+    const en = fb.DictVersion.createDictVersion(b, b.createString('scrabble_en'), b.createString('v1.3.0'));
+    const er = fb.DictVersion.createDictVersion(b, b.createString('erudit_ru'), b.createString('v1.2.0'));
+    const vec = fb.Profile.createDictVersionsVector(b, [en, er]);
+    fb.Profile.startProfile(b);
+    fb.Profile.addUserId(b, uid);
+    fb.Profile.addDictVersions(b, vec);
+    b.finish(fb.Profile.endProfile(b));
+    expect(decodeProfile(b.asUint8Array()).dictVersions).toEqual({ scrabble_en: 'v1.3.0', erudit_ru: 'v1.2.0' });
+  });
+
+  it('decodes an absent dict_versions vector to an empty map', () => {
+    const b = new Builder(64);
+    const uid = b.createString('u-1');
+    fb.Profile.startProfile(b);
+    fb.Profile.addUserId(b, uid);
+    b.finish(fb.Profile.endProfile(b));
+    expect(decodeProfile(b.asUint8Array()).dictVersions).toEqual({});
+  });
+
   it('encodes the update-profile variant preferences', () => {
     const buf = encodeUpdateProfile({
       displayName: 'Kaya',

ui/src/lib/codec.ts

@@ -364,9 +364,25 @@ export function decodeProfile(buf: Uint8Array): Profile {
     email: s(p.email()),
     telegramLinked: p.telegramLinked(),
     vkLinked: p.vkLinked(),
+    dictVersions: decodeDictVersions(p),
   };
 }
 
+// decodeDictVersions reads the profile's per-variant current dictionary versions into a
+// variant-keyed map, so the offline preloader can look up the version for each enabled
+// variant. An entry with an unknown variant or empty version is skipped.
+function decodeDictVersions(p: fb.Profile): Partial<Record<Variant, string>> {
+  const out: Partial<Record<Variant, string>> = {};
+  for (let i = 0; i < p.dictVersionsLength(); i++) {
+    const dv = p.dictVersions(i);
+    if (!dv) continue;
+    const variant = s(dv.variant()) as Variant;
+    const version = s(dv.version());
+    if (variant && version) out[variant] = version;
+  }
+  return out;
+}
+
 // decodeVariantPreferences reads the Profile.variant_preferences vector (the variants
 // the player enabled in Settings).
 function decodeVariantPreferences(p: fb.Profile): Variant[] {
@@ -445,6 +461,7 @@ function decodeStateViewTable(v: fb.StateView): StateView {
     bagLen: v.bagLen(),
     hintsRemaining: v.hintsRemaining(),
     walletBalance: v.walletBalance(),
+    hintUnlockLeftSeconds: v.hintUnlockLeftSeconds(),
   };
 }
 

ui/src/lib/connection.svelte.ts

@@ -9,6 +9,7 @@
 // other traffic is in flight.
 
 import { backoffMs } from './retry';
+import { offlineMode } from './offline.svelte';
 
 let online = $state(true);
 let watchTimer: ReturnType<typeof setTimeout> | null = null;
@@ -27,6 +28,24 @@ export function registerProbe(fn: () => Promise<void>): void {
   probe = fn;
 }
 
+/**
+ * checkReachable runs the reachability probe once, bounded by timeoutMs, and reports whether the
+ * gateway answered — a single attempt (no retry loop), for the cold-start network decision — while
+ * updating the online signal. It reports false when no probe is registered or the timeout wins.
+ */
+export async function checkReachable(timeoutMs: number): Promise<boolean> {
+  if (!probe) return false;
+  try {
+    await Promise.race([
+      probe(),
+      new Promise<never>((_, reject) => setTimeout(() => reject(new Error('reachability timeout')), timeoutMs)),
+    ]);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
 /** reportOnline marks the gateway reachable and stops the watcher. */
 export function reportOnline(): void {
   online = true;
@@ -51,7 +70,9 @@ function scheduleProbe(attempt: number): void {
   watchTimer = setTimeout(
     () => {
       watchTimer = null;
-      if (online || !probe) return;
+      // Never probe the network in offline mode (the kill switch); the online/offline events drive
+      // recovery there instead.
+      if (online || !probe || offlineMode.active) return;
       probe().then(reportOnline, () => scheduleProbe(Math.min(attempt + 1, 6)));
     },
     backoffMs(attempt),

ui/src/lib/dict/dawg.cursor.test.ts

@@ -0,0 +1,68 @@
+import { describe, it, expect } from 'vitest';
+import { readFileSync } from 'node:fs';
+import { Dawg } from './dawg';
+
+// The step-by-step DAWG cursor (root/final/next/arcs) is the primitive the move
+// generator walks. These fast unit tests pin it against a small committed sample
+// dictionary (backend/cmd/movegen); the full parity vs the Go solver lands with
+// the generator's conformance fixtures.
+const bytes = new Uint8Array(readFileSync(new URL('./testdata/sample_en.dawg', import.meta.url)));
+const fixture = JSON.parse(
+  readFileSync(new URL('./testdata/sample_en.words.json', import.meta.url), 'utf8'),
+) as { numAdded: number; words: string[]; indexes: number[][] };
+
+const key = (w: number[]): string => w.join(',');
+
+// enumerateWords walks the whole automaton depth-first, collecting the index path
+// at every accepting node — i.e. every stored word.
+function enumerateWords(d: Dawg): number[][] {
+  const out: number[][] = [];
+  const path: number[] = [];
+  const visit = (node: number): void => {
+    d.arcs(node, (label, dest, final) => {
+      path.push(label);
+      if (final) out.push(path.slice());
+      visit(dest);
+      path.pop();
+      return true;
+    });
+  };
+  if (d.final(d.root())) out.push([]);
+  visit(d.root());
+  return out;
+}
+
+describe('dawg cursor', () => {
+  it('parses the sample fixture', () => {
+    const d = new Dawg(bytes);
+    expect(d.numAdded).toBe(fixture.numAdded);
+  });
+
+  it('root is not an accepting state (the sample has no empty word)', () => {
+    const d = new Dawg(bytes);
+    expect(d.final(d.root())).toBe(false);
+  });
+
+  it('enumerates exactly the stored words', () => {
+    const d = new Dawg(bytes);
+    const got = enumerateWords(d).map(key).sort();
+    const want = fixture.indexes.map(key).sort();
+    expect(got).toEqual(want);
+  });
+
+  it('next walks a stored word to an accepting node and rejects a non-edge', () => {
+    const d = new Dawg(bytes);
+    let node = d.root();
+    for (const ch of [2, 0, 17, 4, 3]) {
+      // "cared"
+      node = d.next(node, ch);
+      expect(node).toBeGreaterThanOrEqual(0);
+    }
+    expect(d.final(node)).toBe(true);
+    // "care" (index [2,0,17,4]) is an internal accepting node on the way to "cared".
+    const care = [2, 0, 17, 4].reduce((n, ch) => d.next(n, ch), d.root());
+    expect(d.final(care)).toBe(true);
+    // No stored word starts with 'z' (index 25).
+    expect(d.next(d.root(), 25)).toBe(-1);
+  });
+});

ui/src/lib/dict/dawg.ts

@@ -95,6 +95,85 @@ export class Dawg {
     return this.indexOf(word) >= 0;
   }
 
+  // --- Step-by-step traversal (the move generator's primitive) ---------------
+  //
+  // A `Node` is a bit offset into the graph; 0 denotes the root (which resolves
+  // to firstNodeOffset). These mirror dafsa's traverse.go Cursor (Root/Final/
+  // Next/Arcs) over the same bitstream this reader already decodes, so the ported
+  // generator can drive the automaton one transition at a time. Single-threaded
+  // JS shares this reader's position across calls; every method re-seeks to its
+  // node on entry, and arcs brackets the callback with a save/restore, so nested
+  // use during a walk is safe. Mirrors dafsa (*Cursor).
+
+  /** root returns the start state of the automaton. */
+  root(): number {
+    return 0;
+  }
+
+  /** final reports whether node is an accepting state (a stored word ends there). */
+  final(node: number): boolean {
+    if (this.numEdges <= 0) {
+      return this.hasEmptyWord && node === 0;
+    }
+    this.p = node === 0 ? this.firstNodeOffset : node;
+    return this.readBits(1) === 1;
+  }
+
+  /**
+   * next follows the edge labelled ch (an alphabet index) from node, returning the
+   * destination node, or -1 when no such edge exists.
+   */
+  next(node: number, ch: number): number {
+    return this.getEdge(node, ch) ? this.eNode : -1;
+  }
+
+  /**
+   * arcs calls fn for each out-edge of node in ascending label order, passing the
+   * edge's label, its destination node and whether that destination is accepting.
+   * It stops early if fn returns false. Mirrors dafsa (*Cursor).Arcs.
+   */
+  arcs(node: number, fn: (label: number, dest: number, final: boolean) => boolean): void {
+    if (this.numEdges <= 0) {
+      return;
+    }
+    this.p = node === 0 ? this.firstNodeOffset : node;
+    this.readBits(1); // node final flag — not needed here
+    const fallthrough = this.readBits(1);
+
+    if (fallthrough === 1) {
+      const label = this.readBits(this.cbits);
+      // The reader now sits at the destination node, whose first bit is its final flag.
+      const dest = this.p;
+      const final = this.readBits(1) === 1;
+      fn(label, dest, final);
+      return;
+    }
+
+    const nskiplen = bitsLen(this.wbits);
+    let nskip = 0;
+    let numEdges = 1;
+    if (this.readBits(1) !== 1) {
+      // not a single edge
+      numEdges = this.readUnsigned();
+      nskip = this.readBits(nskiplen);
+    }
+
+    for (let i = 0; i < numEdges; i++) {
+      const label = this.readBits(this.cbits);
+      if (i > 0) {
+        this.readBits(nskip); // per-edge skip count, unused for traversal
+      }
+      const dest = this.readBits(this.abits);
+      const resume = this.p;
+      this.p = dest;
+      const final = this.readBits(1) === 1;
+      if (!fn(label, dest, final)) {
+        return;
+      }
+      this.p = resume;
+    }
+  }
+
   // getEdge resolves the outgoing edge for ch from the node at the given bit
   // offset. On success it fills eNode/eCount/eFinal and returns true. Mirrors
   // dafsa (*dawg).getEdge.

ui/src/lib/dict/generate.parity.test.ts

@@ -0,0 +1,99 @@
+import { describe, it, expect } from 'vitest';
+import { readFileSync } from 'node:fs';
+import { Dawg } from './dawg';
+import { generateMoves, GenRack, type GenBoard, type Mode } from './generate';
+import type { Ruleset } from './validate';
+
+// Conformance gate for the ported move generator: for each committed position it must
+// return exactly the ranked play list the real Go solver returns (backend/cmd/movegen).
+// The Russian sample reaches alphabet index 32, exercising the 33-letter cross-set.
+
+interface Tile {
+  row: number;
+  col: number;
+  letter: number;
+  blank: boolean;
+}
+interface GenMove {
+  dir: number;
+  tiles: Tile[];
+  score: number;
+}
+interface Fixture {
+  ruleset: {
+    size: number;
+    cols: number;
+    center: number;
+    rackSize: number;
+    bingo: number;
+    values: number[];
+    letterMult: number[][];
+    wordMult: number[][];
+  };
+  cases: {
+    name: string;
+    placed: Tile[] | null;
+    rack: { letters: number[]; blanks: number };
+    mode: number;
+    ignoreCrossWords: boolean;
+    moves: GenMove[];
+  }[];
+}
+
+function load(tag: string): { dawg: Dawg; fx: Fixture } {
+  const bytes = new Uint8Array(readFileSync(new URL(`./testdata/sample_${tag}.dawg`, import.meta.url)));
+  const fx = JSON.parse(
+    readFileSync(new URL(`./testdata/sample_${tag}.gen.json`, import.meta.url), 'utf8'),
+  ) as Fixture;
+  return { dawg: new Dawg(bytes), fx };
+}
+
+function buildBoard(placed: Tile[], cols: number): GenBoard {
+  const grid: ({ letter: number; blank: boolean } | null)[] = new Array(cols * cols).fill(null);
+  for (const t of placed) grid[t.row * cols + t.col] = { letter: t.letter, blank: t.blank };
+  const inBounds = (r: number, c: number): boolean => r >= 0 && r < cols && c >= 0 && c < cols;
+  return {
+    rows: cols,
+    cols,
+    inBounds,
+    filled: (r, c) => inBounds(r, c) && grid[r * cols + c] !== null,
+    cellAt: (r, c) => grid[r * cols + c]!,
+    isEmpty: () => placed.length === 0,
+  };
+}
+
+function rulesetFor(fx: Fixture, ignoreCrossWords: boolean): Ruleset {
+  const r = fx.ruleset;
+  return {
+    cols: r.cols,
+    center: r.center,
+    rackSize: r.rackSize,
+    bingo: r.bingo,
+    values: r.values,
+    letterMult: (row, col) => r.letterMult[row][col],
+    wordMult: (row, col) => r.wordMult[row][col],
+    ignoreCrossWords,
+  };
+}
+
+// sig is an order-stable signature of a move: orientation, score and its placed tiles
+// sorted by square — so two lists compare equal iff they rank the same plays the same way.
+function sig(m: GenMove): string {
+  const ts = m.tiles.slice().sort((a, b) => (a.row !== b.row ? a.row - b.row : a.col - b.col));
+  return `${m.dir}#${m.score}#` + ts.map((t) => `${t.row},${t.col},${t.letter}${t.blank ? '*' : ''}`).join(';');
+}
+
+for (const tag of ['en', 'ru']) {
+  describe(`move generator parity vs Go solver (${tag})`, () => {
+    const { dawg, fx } = load(tag);
+    for (const c of fx.cases) {
+      it(c.name, () => {
+        const board = buildBoard(c.placed ?? [], fx.ruleset.cols);
+        const rack = GenRack.from(fx.ruleset.size, c.rack.letters, c.rack.blanks);
+        const rs = rulesetFor(fx, c.ignoreCrossWords);
+        const got = generateMoves(dawg, board, rack, rs, c.mode as Mode);
+        expect(got.map(sig)).toEqual(c.moves.map(sig));
+      });
+    }
+  });
+}

ui/src/lib/dict/generate.realparity.test.ts

@@ -0,0 +1,113 @@
+import { describe, it, expect } from 'vitest';
+import { readFileSync, existsSync } from 'node:fs';
+import { join } from 'node:path';
+import { Dawg } from './dawg';
+import { generateMoves, GenRack, type GenBoard, type Mode } from './generate';
+import type { Ruleset } from './validate';
+
+// Full-dictionary conformance for the ported move generator: for positions over the real
+// shipped dictionaries (deep graphs and full 26/33-letter alphabets the tiny committed
+// samples cannot reach) it must return exactly the ranked list the Go solver does. The
+// golden vectors come from `go run ./backend/cmd/movegen -dawg-dir <dawg> -out <dir>` and
+// the CI conformance job wires the two directories in; the suite skips when they are unset.
+const dawgDir = process.env.DICT_DAWG_DIR;
+const goldDir = process.env.DICT_MOVEGEN_DIR;
+const ready = !!dawgDir && !!goldDir && existsSync(dawgDir) && existsSync(goldDir);
+
+// variant -> the release dawg file name (matches dawg.parity.test.ts / the movegen tool).
+const variants = [
+  { variant: 'scrabble_en', dawg: 'en_sowpods' },
+  { variant: 'scrabble_ru', dawg: 'ru_scrabble' },
+  { variant: 'erudit_ru', dawg: 'ru_erudit' },
+];
+
+interface Tile {
+  row: number;
+  col: number;
+  letter: number;
+  blank: boolean;
+}
+interface GenMove {
+  dir: number;
+  tiles: Tile[];
+  score: number;
+}
+interface Fixture {
+  ruleset: {
+    size: number;
+    cols: number;
+    center: number;
+    rackSize: number;
+    bingo: number;
+    values: number[];
+    letterMult: number[][];
+    wordMult: number[][];
+  };
+  cases: {
+    name: string;
+    placed: Tile[] | null;
+    rack: { letters: number[]; blanks: number };
+    mode: number;
+    ignoreCrossWords: boolean;
+    moves: GenMove[];
+  }[];
+}
+
+function buildBoard(placed: Tile[], cols: number): GenBoard {
+  const grid: ({ letter: number; blank: boolean } | null)[] = new Array(cols * cols).fill(null);
+  for (const t of placed) grid[t.row * cols + t.col] = { letter: t.letter, blank: t.blank };
+  const inBounds = (r: number, c: number): boolean => r >= 0 && r < cols && c >= 0 && c < cols;
+  return {
+    rows: cols,
+    cols,
+    inBounds,
+    filled: (r, c) => inBounds(r, c) && grid[r * cols + c] !== null,
+    cellAt: (r, c) => grid[r * cols + c]!,
+    isEmpty: () => placed.length === 0,
+  };
+}
+
+function rulesetFor(fx: Fixture, ignoreCrossWords: boolean): Ruleset {
+  const r = fx.ruleset;
+  return {
+    cols: r.cols,
+    center: r.center,
+    rackSize: r.rackSize,
+    bingo: r.bingo,
+    values: r.values,
+    letterMult: (row, col) => r.letterMult[row][col],
+    wordMult: (row, col) => r.wordMult[row][col],
+    ignoreCrossWords,
+  };
+}
+
+function sig(m: GenMove): string {
+  const ts = m.tiles.slice().sort((a, b) => (a.row !== b.row ? a.row - b.row : a.col - b.col));
+  return `${m.dir}#${m.score}#` + ts.map((t) => `${t.row},${t.col},${t.letter}${t.blank ? '*' : ''}`).join(';');
+}
+
+describe.skipIf(!ready)('move generator parity vs Go on the real dictionaries', () => {
+  for (const v of variants) {
+    describe(v.variant, () => {
+      // Guard the collection-time reads: the block is skipped when the dirs are unset, but
+      // the describe callback still runs to register tests, so touch the filesystem only
+      // when ready (otherwise join(undefined, …) would throw during a normal unit run).
+      if (!ready) return;
+      const fx = JSON.parse(readFileSync(join(goldDir!, `${v.variant}.movegen.json`), 'utf8')) as Fixture;
+      const dawg = new Dawg(new Uint8Array(readFileSync(join(dawgDir!, `${v.dawg}.dawg`))));
+      for (const c of fx.cases) {
+        it(
+          c.name,
+          () => {
+            const board = buildBoard(c.placed ?? [], fx.ruleset.cols);
+            const rack = GenRack.from(fx.ruleset.size, c.rack.letters, c.rack.blanks);
+            const rs = rulesetFor(fx, c.ignoreCrossWords);
+            const got = generateMoves(dawg, board, rack, rs, c.mode as Mode);
+            expect(got.map(sig)).toEqual(c.moves.map(sig));
+          },
+          60_000,
+        );
+      }
+    });
+  }
+});

ui/src/lib/dict/generate.ts

@@ -0,0 +1,418 @@
+// Local move generator: every legal play for a rack on a board, ranked by
+// descending score. Ported from the scrabble-solver engine — the Appel-Jacobson
+// two-phase algorithm (LeftPart then ExtendRight) over a plain left-to-right DAWG
+// (scrabble/gen_dawg.go, gen.go, crossset.go, solver.go, key.go). It walks the DAWG
+// with the cursor from dawg.ts and scores each play with evaluate() from validate.ts,
+// so the whole robot brain runs on-device. Faithfulness to the Go solver is pinned by
+// generate.parity.test.ts against golden fixtures (backend/cmd/movegen).
+//
+// Everything works in alphabet-index space, mirroring the Go engine. A letterSet is
+// a per-square cross-set (the letters that form a legal perpendicular word there);
+// it is a boolean membership array rather than a uint64, so alphabet indexes past
+// JS's 31-bit shift boundary (Russian has 33 letters) are handled exactly.
+
+import { Dawg } from './dawg';
+import {
+  evaluate,
+  connected,
+  Horizontal,
+  Vertical,
+  type Board,
+  type Ruleset,
+  type Move,
+  type Placement,
+  type Direction,
+} from './validate';
+
+/** Both generates across plays (on the board) and down plays (on its transpose). */
+export const Both = 0;
+/** OnlyHorizontal generates across plays only. */
+export const OnlyHorizontal = 1;
+/** OnlyVertical generates down plays only (Эрудит plays a single orientation per turn). */
+export const OnlyVertical = 2;
+export type Mode = typeof Both | typeof OnlyHorizontal | typeof OnlyVertical;
+
+function modeIncludes(mode: Mode, dir: Direction): boolean {
+  if (mode === Both) return true;
+  if (mode === OnlyHorizontal) return dir === Horizontal;
+  return dir === Vertical;
+}
+
+/**
+ * GenBoard is the board view the generator needs: the validator's read view plus the
+ * dimensions it iterates over. The whole board is square, so a transposed view (below)
+ * satisfies the same shape.
+ */
+export interface GenBoard extends Board {
+  rows: number;
+  cols: number;
+}
+
+/**
+ * GenRack is a rack as per-letter tile counts plus a blank slot, mirroring
+ * scrabble-solver/rack. The generator mutates a single rack in place — removing a
+ * tile, recursing, putting it back — so the operations are O(1) and allocation-free.
+ */
+export class GenRack {
+  private readonly counts: Int32Array;
+
+  /** Construct an empty rack for an alphabet of the given size (a trailing blank slot). */
+  constructor(size: number) {
+    this.counts = new Int32Array(size + 1);
+  }
+
+  /** from builds a rack from a multiset of letter indexes plus a blank count. */
+  static from(size: number, letters: readonly number[], blanks: number): GenRack {
+    const r = new GenRack(size);
+    for (const l of letters) r.counts[l]++;
+    r.counts[size] += blanks;
+    return r;
+  }
+
+  /** has reports whether at least one tile of the letter index is on the rack. */
+  has(letter: number): boolean {
+    return this.counts[letter] > 0;
+  }
+  /** blanks returns how many blank tiles are on the rack. */
+  blanks(): number {
+    return this.counts[this.counts.length - 1];
+  }
+  remove(letter: number): void {
+    this.counts[letter]--;
+  }
+  add(letter: number): void {
+    this.counts[letter]++;
+  }
+  removeBlank(): void {
+    this.counts[this.counts.length - 1]--;
+  }
+  addBlank(): void {
+    this.counts[this.counts.length - 1]++;
+  }
+  /** clone returns an independent copy. */
+  clone(): GenRack {
+    const c = new GenRack(this.counts.length - 1);
+    c.counts.set(this.counts);
+    return c;
+  }
+}
+
+// --- cross-sets ------------------------------------------------------------------
+//
+// A LetterSet is membership over alphabet letter indexes. Mirrors scrabble.letterSet
+// (a uint64) but as a Uint8Array so index 32 (Russian) is exact under JS bit ops.
+type LetterSet = Uint8Array;
+
+function fullSet(size: number): LetterSet {
+  return new Uint8Array(size).fill(1);
+}
+
+// walk follows word (alphabet indexes) left to right from the root; -1 if it derails.
+function walk(dawg: Dawg, word: readonly number[]): number {
+  let n = dawg.root();
+  for (const l of word) {
+    n = dawg.next(n, l);
+    if (n < 0) return -1;
+  }
+  return n;
+}
+
+// completers returns the letters X (< size) whose arc from state leads directly to an
+// accepting node — the deterministic cross-set primitive. Mirrors scrabble.completers.
+function completers(dawg: Dawg, state: number, size: number): LetterSet {
+  const set = new Uint8Array(size);
+  dawg.arcs(state, (label, _dest, final) => {
+    if (final && label < size) set[label] = 1;
+    return true;
+  });
+  return set;
+}
+
+// dawgCrossSet returns the letters X for which above·X·below is a stored word. Mirrors
+// scrabble.dawgCrossSet: a right extension (no tiles below) just completes the prefix
+// above; a left extension (tiles below) probes each X. above/below are letter indexes.
+function dawgCrossSet(dawg: Dawg, above: number[], below: number[], size: number): LetterSet {
+  if (above.length === 0 && below.length === 0) return fullSet(size);
+  if (below.length === 0) {
+    const node = walk(dawg, above);
+    if (node < 0) return new Uint8Array(size);
+    return completers(dawg, node, size);
+  }
+  let node = dawg.root();
+  if (above.length > 0) {
+    node = walk(dawg, above);
+    if (node < 0) return new Uint8Array(size);
+  }
+  const set = new Uint8Array(size);
+  for (let x = 0; x < size; x++) {
+    let m = dawg.next(node, x);
+    if (m < 0) continue;
+    let ok = true;
+    for (const l of below) {
+      m = dawg.next(m, l);
+      if (m < 0) {
+        ok = false;
+        break;
+      }
+    }
+    if (ok && dawg.final(m)) set[x] = 1;
+  }
+  return set;
+}
+
+// columnContext returns the contiguous run of filled cells immediately above and below
+// the empty square (r, c), each top to bottom, as letter indexes — the tiles a
+// perpendicular word through (r, c) would include. Mirrors scrabble.columnContext.
+function columnContext(b: GenBoard, r: number, c: number): { above: number[]; below: number[] } {
+  const above: number[] = [];
+  let start = r;
+  while (start - 1 >= 0 && b.filled(start - 1, c)) start--;
+  for (let rr = start; rr < r; rr++) above.push(b.cellAt(rr, c).letter);
+
+  const below: number[] = [];
+  let end = r;
+  while (end + 1 < b.rows && b.filled(end + 1, c)) end++;
+  for (let rr = r + 1; rr <= end; rr++) below.push(b.cellAt(rr, c).letter);
+  return { above, below };
+}
+
+// transpose returns a view of b with rows and columns swapped, so down-play generation
+// runs as across generation. Mirrors board.Transpose (as a lazy view).
+function transpose(b: GenBoard): GenBoard {
+  return {
+    rows: b.cols,
+    cols: b.rows,
+    inBounds: (r, c) => b.inBounds(c, r),
+    filled: (r, c) => b.filled(c, r),
+    cellAt: (r, c) => b.cellAt(c, r),
+    isEmpty: () => b.isEmpty(),
+  };
+}
+
+// A tentatively placed left-part tile; its column is fixed only at record time.
+interface TileInfo {
+  letter: number;
+  blank: boolean;
+}
+
+// AcrossGen carries one across-generation pass over a board. Mirrors scrabble.acrossGen.
+class AcrossGen {
+  private row = 0;
+  private readonly left: TileInfo[] = [];
+  private readonly right: Placement[] = [];
+
+  constructor(
+    private readonly dawg: Dawg,
+    private readonly bd: GenBoard,
+    private readonly rk: GenRack,
+    private readonly cross: (r: number, c: number) => LetterSet,
+    private readonly emit: (placements: Placement[]) => void,
+  ) {}
+
+  generateRow(row: number, firstMove: boolean, centerRow: number, centerCol: number): void {
+    this.row = row;
+    let limit = 0;
+    for (let col = 0; col < this.bd.cols; col++) {
+      if (this.bd.filled(row, col)) {
+        limit = 0;
+        continue;
+      }
+      const anchor = firstMove ? row === centerRow && col === centerCol : this.hasFilledNeighbor(row, col);
+      if (!anchor) {
+        limit++;
+        continue;
+      }
+      this.left.length = 0;
+      this.right.length = 0;
+      if (col > 0 && this.bd.filled(row, col - 1)) {
+        const pre = this.walkPrefix(row, col);
+        if (pre.ok) this.extendRight(pre.node, col, col);
+      } else {
+        this.leftPart(this.dawg.root(), col, limit);
+      }
+      limit = 0;
+    }
+  }
+
+  private hasFilledNeighbor(r: number, c: number): boolean {
+    return this.bd.filled(r - 1, c) || this.bd.filled(r + 1, c) || this.bd.filled(r, c - 1) || this.bd.filled(r, c + 1);
+  }
+
+  // walkPrefix walks the DAWG through the filled run ending at col-1, returning the
+  // node reached and whether that prefix exists. Mirrors scrabble.acrossGen.walkPrefix.
+  private walkPrefix(row: number, col: number): { node: number; ok: boolean } {
+    let start = col - 1;
+    while (start - 1 >= 0 && this.bd.filled(row, start - 1)) start--;
+    let node = this.dawg.root();
+    for (let c = start; c < col; c++) {
+      node = this.dawg.next(node, this.bd.cellAt(row, c).letter);
+      if (node < 0) return { node, ok: false };
+    }
+    return { node, ok: true };
+  }
+
+  // leftPart places left-part tiles from the rack (up to limit), calling extendRight
+  // after each prefix. Mirrors scrabble.acrossGen.leftPart.
+  private leftPart(node: number, anchorCol: number, limit: number): void {
+    this.extendRight(node, anchorCol, anchorCol);
+    if (limit === 0) return;
+    this.dawg.arcs(node, (label, dest) => {
+      if (this.rk.has(label)) {
+        this.rk.remove(label);
+        this.left.push({ letter: label, blank: false });
+        this.leftPart(dest, anchorCol, limit - 1);
+        this.left.pop();
+        this.rk.add(label);
+      }
+      if (this.rk.blanks() > 0) {
+        this.rk.removeBlank();
+        this.left.push({ letter: label, blank: true });
+        this.leftPart(dest, anchorCol, limit - 1);
+        this.left.pop();
+        this.rk.addBlank();
+      }
+      return true;
+    });
+  }
+
+  // extendRight extends the word rightward from col, placing rack tiles on empty
+  // squares (constrained by cross-sets) and following board tiles. A word is recorded
+  // only past the anchor. Mirrors scrabble.acrossGen.extendRight.
+  private extendRight(node: number, col: number, anchorCol: number): void {
+    if (col >= this.bd.cols) {
+      if (col > anchorCol && this.dawg.final(node)) this.record(anchorCol);
+      return;
+    }
+    if (this.bd.filled(this.row, col)) {
+      const dest = this.dawg.next(node, this.bd.cellAt(this.row, col).letter);
+      if (dest >= 0) this.extendRight(dest, col + 1, anchorCol);
+      return;
+    }
+
+    if (col > anchorCol && this.dawg.final(node)) this.record(anchorCol);
+    const cross = this.cross(this.row, col);
+    this.dawg.arcs(node, (label, dest) => {
+      if (cross[label] !== 1) return true;
+      if (this.rk.has(label)) {
+        this.rk.remove(label);
+        this.right.push({ row: this.row, col, letter: label, blank: false });
+        this.extendRight(dest, col + 1, anchorCol);
+        this.right.pop();
+        this.rk.add(label);
+      }
+      if (this.rk.blanks() > 0) {
+        this.rk.removeBlank();
+        this.right.push({ row: this.row, col, letter: label, blank: true });
+        this.extendRight(dest, col + 1, anchorCol);
+        this.right.pop();
+        this.rk.addBlank();
+      }
+      return true;
+    });
+  }
+
+  // record assembles the play (left part at fixed columns, then the right part) and
+  // reports it, skipping plays that lay no new tile. Mirrors scrabble.acrossGen.record.
+  private record(anchorCol: number): void {
+    if (this.left.length + this.right.length === 0) return;
+    const placements: Placement[] = [];
+    const leftStart = anchorCol - this.left.length;
+    for (let i = 0; i < this.left.length; i++) {
+      placements.push({ row: this.row, col: leftStart + i, letter: this.left[i].letter, blank: this.left[i].blank });
+    }
+    for (const p of this.right) placements.push(p);
+    this.emit(placements);
+  }
+}
+
+// runAcross generates all across plays on bd and reports each via emit in bd's
+// coordinates. Cross-sets are computed lazily (vertical words on bd) and cached.
+// Mirrors DAWGGenerator.runAcross.
+function runAcross(
+  dawg: Dawg,
+  bd: GenBoard,
+  rk: GenRack,
+  size: number,
+  rs: Ruleset,
+  centerRow: number,
+  centerCol: number,
+  emit: (placements: Placement[]) => void,
+): void {
+  let crossFn: (r: number, c: number) => LetterSet;
+  if (rs.ignoreCrossWords) {
+    const full = fullSet(size);
+    crossFn = () => full;
+  } else {
+    const cache = new Array<LetterSet | undefined>(bd.rows * bd.cols);
+    crossFn = (r, c) => {
+      const i = r * bd.cols + c;
+      let s = cache[i];
+      if (!s) {
+        const { above, below } = columnContext(bd, r, c);
+        s = dawgCrossSet(dawg, above, below, size);
+        cache[i] = s;
+      }
+      return s;
+    };
+  }
+
+  const ag = new AcrossGen(dawg, bd, rk, crossFn, emit);
+  const firstMove = bd.isEmpty();
+  for (let row = 0; row < bd.rows; row++) {
+    ag.generateRow(row, firstMove, centerRow, centerCol);
+  }
+}
+
+// moveKey is a canonical string identifying a play (direction plus its placed tiles),
+// used to de-duplicate and rank generated moves. Mirrors scrabble.moveKey.
+export function moveKey(dir: Direction, placements: readonly Placement[]): string {
+  const ps = placements.slice().sort((a, b) => (a.row !== b.row ? a.row - b.row : a.col - b.col));
+  let s = String(dir);
+  for (const p of ps) s += `;${p.row},${p.col},${p.letter}${p.blank ? '*' : ''}`;
+  return s;
+}
+
+/**
+ * generateMoves returns every legal play for rack on board in the mode's orientations,
+ * ranked by descending score (ties broken by the canonical move key). It walks the DAWG
+ * with the cursor and scores each play with evaluate(); the alphabet size is taken from
+ * the ruleset's value table. Mirrors (*Solver).GenerateMovesOpts (the ruleset carries
+ * ignoreCrossWords for the single-word rule).
+ */
+export function generateMoves(dawg: Dawg, board: GenBoard, rack: GenRack, rs: Ruleset, mode: Mode = Both): Move[] {
+  const size = rs.values.length;
+  const rk = rack.clone(); // generation mutates the rack in place and restores it
+  const centerRow = Math.floor(rs.center / rs.cols);
+  const centerCol = rs.center % rs.cols;
+
+  const moves: Move[] = [];
+  const seen = new Set<string>();
+  const emit = (dir: Direction, placements: Placement[]): void => {
+    const key = moveKey(dir, placements);
+    if (seen.has(key)) return;
+    const res = evaluate(board, rs, dir, placements);
+    if (res.err || !res.move) return;
+    seen.add(key);
+    moves.push(res.move);
+  };
+
+  if (modeIncludes(mode, Horizontal)) {
+    runAcross(dawg, board, rk, size, rs, centerRow, centerCol, (p) => emit(Horizontal, p));
+  }
+  if (modeIncludes(mode, Vertical)) {
+    const tb = transpose(board);
+    runAcross(dawg, tb, rk, size, rs, centerCol, centerRow, (p) => {
+      const rp = p.map((pl) => ({ row: pl.col, col: pl.row, letter: pl.letter, blank: pl.blank }));
+      emit(Vertical, rp);
+    });
+  }
+
+  const kept = moves.filter((m) => connected(board, rs, m));
+  kept.sort((a, b) => {
+    if (a.score !== b.score) return b.score - a.score;
+    const ka = moveKey(a.dir, a.tiles);
+    const kb = moveKey(b.dir, b.tiles);
+    return ka < kb ? -1 : ka > kb ? 1 : 0;
+  });
+  return kept;
+}

ui/src/lib/dict/offlineready.ts

@@ -0,0 +1,27 @@
+// Browser orchestration for the offline-toggle readiness wait. Lazily imported by
+// offline.svelte.ts's requestOffline so the dict loader/generator it pulls in stays out of the main
+// bundle. It runs the same cache-first preload as the background warmup (preload.ts), but bounded by
+// a UI wait: it tells the toggle whether flipping to offline can succeed right now, and leaves the
+// fetch running on a timeout so a later flip is instant.
+
+import type { Profile } from '../model';
+import { preloadDicts } from './preload';
+import { getDawg, dictLoadingDisabled } from '../dict';
+import { raceOfflineReady } from '../offline';
+
+/**
+ * ensureOfflineDicts fetches the profile's enabled variants' dictionaries cache-first (instant when
+ * already warm, a network fetch otherwise) and reports, within budgetMs, whether every one is
+ * available — the offline toggle's readiness gate. With no enabled variant there is nothing to play
+ * offline, so it is never ready. The fetch is not aborted on a timeout; it keeps warming the
+ * on-device cache in the background so a later flip to offline succeeds immediately.
+ */
+export async function ensureOfflineDicts(prof: Profile, budgetMs: number): Promise<boolean> {
+  if (prof.variantPreferences.length === 0) return false;
+  const run = preloadDicts(prof.dictVersions, prof.variantPreferences, {
+    getDawg,
+    disabled: dictLoadingDisabled,
+    retries: 1,
+  });
+  return raceOfflineReady(run, budgetMs);
+}

ui/src/lib/dict/preload.test.ts

@@ -0,0 +1,86 @@
+import { describe, it, expect } from 'vitest';
+import { preloadDicts } from './preload';
+import type { Variant } from '../model';
+import type { Dawg } from './dawg';
+
+// A non-null stand-in for a loaded reader — preloadDicts only checks getDawg's result for null.
+const DAWG = {} as Dawg;
+const noSleep = (): Promise<void> => Promise.resolve();
+
+describe('preloadDicts', () => {
+  it('fetches every enabled variant that has a known version', async () => {
+    const calls: string[] = [];
+    const res = await preloadDicts({ scrabble_en: 'v1', scrabble_ru: 'v2', erudit_ru: 'v3' }, ['scrabble_en', 'erudit_ru'], {
+      getDawg: async (v: Variant, ver: string) => {
+        calls.push(`${v}@${ver}`);
+        return DAWG;
+      },
+      disabled: () => false,
+      sleep: noSleep,
+    });
+    expect(res.ok).toEqual(['scrabble_en', 'erudit_ru']);
+    expect(res.failed).toEqual([]);
+    expect(calls).toEqual(['scrabble_en@v1', 'erudit_ru@v3']);
+  });
+
+  it('marks a variant with no known version as failed without fetching it', async () => {
+    const calls: string[] = [];
+    const res = await preloadDicts({ scrabble_en: 'v1' }, ['scrabble_en', 'scrabble_ru'], {
+      getDawg: async (v: Variant) => {
+        calls.push(v);
+        return DAWG;
+      },
+      disabled: () => false,
+      sleep: noSleep,
+    });
+    expect(res.ok).toEqual(['scrabble_en']);
+    expect(res.failed).toEqual(['scrabble_ru']);
+    expect(calls).toEqual(['scrabble_en']);
+  });
+
+  it('retries a transient failure with linear backoff, then succeeds', async () => {
+    let attempts = 0;
+    const waits: number[] = [];
+    const res = await preloadDicts({ scrabble_en: 'v1' }, ['scrabble_en'], {
+      getDawg: async () => (++attempts >= 3 ? DAWG : null),
+      disabled: () => false,
+      sleep: async (ms: number) => void waits.push(ms),
+      retries: 3,
+      backoffMs: 100,
+    });
+    expect(res.ok).toEqual(['scrabble_en']);
+    expect(attempts).toBe(3);
+    expect(waits).toEqual([100, 200]);
+  });
+
+  it('gives up a persistent failure after the retry budget', async () => {
+    let attempts = 0;
+    const res = await preloadDicts({ scrabble_en: 'v1' }, ['scrabble_en'], {
+      getDawg: async () => {
+        attempts++;
+        return null;
+      },
+      disabled: () => false,
+      sleep: noSleep,
+      retries: 2,
+    });
+    expect(res.failed).toEqual(['scrabble_en']);
+    expect(res.ok).toEqual([]);
+    expect(attempts).toBe(3);
+  });
+
+  it('stops retrying once the session miss-breaker trips', async () => {
+    let attempts = 0;
+    const res = await preloadDicts({ scrabble_en: 'v1' }, ['scrabble_en'], {
+      getDawg: async () => {
+        attempts++;
+        return null;
+      },
+      disabled: () => true,
+      sleep: noSleep,
+      retries: 5,
+    });
+    expect(res.failed).toEqual(['scrabble_en']);
+    expect(attempts).toBe(1);
+  });
+});

ui/src/lib/dict/preload.ts

@@ -0,0 +1,68 @@
+// Background dictionary preload for offline readiness. An installed PWA with a confirmed email
+// warms the dictionaries for the player's enabled variants while online, so a later switch to
+// deliberate offline mode has the data it needs. The pure preloadDicts here takes its side effects
+// (getDawg, the session miss-breaker, sleep) as dependencies, so it unit-tests in the node env. The
+// eligibility and once/online guard live in offline.svelte.ts (kickDictPreload); the browser
+// orchestration that supplies the real side effects and raises the in-lobby warning lives in
+// preloadrun.ts, which offline.svelte.ts imports dynamically so neither the loader nor the
+// generator is pulled into the main bundle.
+
+import type { Variant } from '../model';
+import type { Dawg } from './dawg';
+
+/** PreloadDeps injects preloadDicts's side effects so the logic stays pure and testable. */
+export interface PreloadDeps {
+  /** getDawg resolves the (variant, version) reader, serving memory/IndexedDB before the network,
+   *  or null on any miss — mirrors the in-game loader. */
+  getDawg: (variant: Variant, version: string) => Promise<Dawg | null>;
+  /** disabled reports whether the session dictionary miss-breaker has tripped (too many network
+   *  misses this session); when it has, a network fetch will not recover, so retries stop. */
+  disabled: () => boolean;
+  /** sleep waits between retries; defaults to a real timer. */
+  sleep?: (ms: number) => Promise<void>;
+  /** retries is the number of extra attempts after the first (default 2). */
+  retries?: number;
+  /** backoffMs is the base linear backoff between attempts (default 800). */
+  backoffMs?: number;
+}
+
+/** PreloadResult reports which enabled variants ended up available (ok) and which are still
+ *  missing (failed) after the preload — the caller surfaces a warning when failed is non-empty. */
+export interface PreloadResult {
+  ok: Variant[];
+  failed: Variant[];
+}
+
+/**
+ * preloadDicts fetches, via getDawg, the dictionary for each enabled variant that has a known
+ * version, retrying transient misses with linear backoff. A variant with no known version, or one
+ * still missing after the retry budget, lands in failed; the rest in ok. It never throws and stops
+ * retrying a variant once the session miss-breaker (disabled) trips, since the network will not
+ * recover this session — a cached dictionary is still served by getDawg regardless.
+ */
+export async function preloadDicts(
+  versions: Partial<Record<Variant, string>>,
+  enabled: readonly Variant[],
+  deps: PreloadDeps,
+): Promise<PreloadResult> {
+  const sleep = deps.sleep ?? ((ms) => new Promise<void>((r) => setTimeout(r, ms)));
+  const retries = deps.retries ?? 2;
+  const backoffMs = deps.backoffMs ?? 800;
+  const ok: Variant[] = [];
+  const failed: Variant[] = [];
+  for (const variant of enabled) {
+    const version = versions[variant];
+    if (!version) {
+      failed.push(variant);
+      continue;
+    }
+    let dawg: Dawg | null = null;
+    for (let attempt = 0; attempt <= retries; attempt++) {
+      dawg = await deps.getDawg(variant, version);
+      if (dawg || deps.disabled()) break;
+      if (attempt < retries) await sleep(backoffMs * (attempt + 1));
+    }
+    (dawg ? ok : failed).push(variant);
+  }
+  return { ok, failed };
+}

ui/src/lib/dict/preloadrun.ts

@@ -0,0 +1,24 @@
+// Browser-only orchestration for the offline dictionary preload. Kept apart from the pure
+// preloadDicts (preload.ts) — which unit-tests in the node env — and lazily imported by
+// offline.svelte.ts's kickDictPreload, so the dict loader/generator it pulls in stays out of the
+// main bundle. It supplies the real side effects (getDawg, the session miss-breaker) and raises the
+// in-lobby notice when a first-lobby preload cannot fetch every enabled variant's dictionary.
+
+import type { Profile } from '../model';
+import { preloadDicts } from './preload';
+import { getDawg, dictLoadingDisabled } from '../dict';
+import { setDictPreloadWarning } from '../offline.svelte';
+
+/**
+ * runPreload warms the dictionaries for the profile's enabled variants (using the versions the
+ * profile advertises) via the real dict loader, so a later switch to offline mode has the data.
+ * When warnOnFail is set (the first lobby entry), it raises the in-lobby notice if a variant is
+ * still missing afterwards, and clears it on a run where every variant is available.
+ */
+export async function runPreload(prof: Profile, warnOnFail: boolean): Promise<void> {
+  const res = await preloadDicts(prof.dictVersions, prof.variantPreferences, {
+    getDawg,
+    disabled: dictLoadingDisabled,
+  });
+  if (warnOnFail) setDictPreloadWarning(res.failed.length > 0);
+}