Merge pull request 'Release: promote development → master (old Android WebView support + unsupported-engine telemetry)' (#178) from development into master

The index.html boot guard now fires a fire-and-forget beacon (POST /telemetry/unsupported)
when it turns a client away on the unsupported-engine screen, so the owner can see — on the
Users dashboard beside "app opens" — how many real clients hit it and on which engines.

- Client: navigator.sendBeacon (fetch fallback) with a localStorage dedup keyed by app version
  + reason + Chromium, so a user reopening the app is one report, not ten.
- Gateway: a new unauthenticated POST /telemetry/unsupported handler (the client never booted,
  so it carries no session), per-IP public-limited and body-capped, mirroring the export-download
  route. It folds the beacon into the OTel counter unsupported_engine_total {reason =
  no_bigint/no_proxy/boot_error/other, chromium}, with reason allow-listed and the Chromium major
  reduced to a bounded range (normalizeUnsupported) so a spoofed beacon cannot inflate the metric
  cardinality; the full user agent is logged, not labelled.
- Caddy: /telemetry/* added to the @gateway matcher (else it falls to the landing catch-all).
- Grafana: two panels on the Scrabble — Users dashboard (by reason, by Chromium major).
- Docs: ARCHITECTURE.md §11.

Tests: recordUnsupportedEngine (metric split), normalizeUnsupported (cardinality bounding), and
the handler route end to end (204 / 405 / counter). go build+vet+test and gofmt clean; ui
check/build/e2e green; the client beacon + dedup verified against a forced hard-gate (BigInt
removed) — one POST, deduped on reopen, correct reason/chromium/version labels.

.gitea/workflows/ci.yaml

@@ -26,12 +26,12 @@ on:
   push:
     branches: [development]
 
-# The dictionary release the test suite validates against — the current
-# scrabble-dictionary release. Centralised here so a release bump is one edit; the
-# unit/integration jobs inherit it. The deploy job overrides it per contour with
-# vars.TEST_DICT_VERSION (the seed for a fresh volume), see deploy/README.md.
+# The dictionary release. One Gitea variable is the single source of truth: the
+# test suite validates against it here (inherited by the unit/integration jobs) and
+# both contours' deploy jobs seed a fresh volume with the same value. A release bump
+# is one edit (the variable). See deploy/README.md.
 env:
-  DICT_VERSION: v1.3.1
+  DICT_VERSION: ${{ vars.DICT_VERSION }}
 
 jobs:
   # changes detects which areas a PR/push touched, so the test jobs can skip when
@@ -329,24 +329,42 @@ jobs:
           TELEGRAM_PROMO_BOT_TOKEN: ${{ secrets.TEST_TELEGRAM_PROMO_BOT_TOKEN }}
           # VK Mini App protected key (offline HMAC for the launch-param signature); empty
           # leaves the VK auth path (auth.vk) disabled until the operator sets the secret.
-          GATEWAY_VK_APP_SECRET: ${{ secrets.TEST_GATEWAY_VK_APP_SECRET }}
+          # One VK Mini App serves every contour -> unprefixed secret.
+          GATEWAY_VK_APP_SECRET: ${{ secrets.GATEWAY_VK_APP_SECRET }}
+          # VK ID web login (browser VK-identity linking): the VK ID "Web" app's protected key
+          # for the server-side confidential code exchange — a SEPARATE VK app from the Mini
+          # App above. One VK ID "Web" app serves every contour -> unprefixed secret.
+          GATEWAY_VK_ID_CLIENT_SECRET: ${{ secrets.GATEWAY_VK_ID_CLIENT_SECRET }}
+          # Planted honeytoken bearer: presenting it flags the caller (logs + a ban metric on
+          # test where the IP ban is off; a 24h IP ban on prod). Per-contour secret; empty = trap off.
+          GATEWAY_HONEYTOKEN: ${{ secrets.TEST_GATEWAY_HONEYTOKEN }}
           # Signs the finished-game export download URLs (backend + compose interpolation).
           EXPORT_SIGN_KEY: ${{ secrets.TEST_EXPORT_SIGN_KEY }}
-          # Transactional email via the shared Selectel relay. Empty host leaves the
-          # backend on the log mailer (email disabled) but the contour still boots.
-          SMTP_RELAY_USER: ${{ secrets.TEST_SMTP_RELAY_USER }}
-          SMTP_RELAY_PASS: ${{ secrets.TEST_SMTP_RELAY_PASS }}
-          SMTP_RELAY_HOST: ${{ vars.TEST_SMTP_RELAY_HOST }}
-          SMTP_RELAY_PORT: ${{ vars.TEST_SMTP_RELAY_PORT }}
-          SMTP_RELAY_TLS: ${{ vars.TEST_SMTP_RELAY_TLS }}
+          # Transactional email via the shared Selectel relay: one account for every
+          # contour -> unprefixed host/port/tls/user/pass. Empty host leaves the backend
+          # on the log mailer (email disabled) but the contour still boots.
+          SMTP_RELAY_USER: ${{ secrets.SMTP_RELAY_USER }}
+          SMTP_RELAY_PASS: ${{ secrets.SMTP_RELAY_PASS }}
+          SMTP_RELAY_HOST: ${{ vars.SMTP_RELAY_HOST }}
+          SMTP_RELAY_PORT: ${{ vars.SMTP_RELAY_PORT }}
+          SMTP_RELAY_TLS: ${{ vars.SMTP_RELAY_TLS }}
           SMTP_RELAY_FROM: ${{ vars.TEST_SMTP_RELAY_FROM }}
+          # Operator alerts: backend admin emails (new feedback / complaints) + Grafana
+          # infra alerts. Distinct senders + recipients; Grafana uses the relay's STARTTLS
+          # host:port. Empty leaves the alert worker off and Grafana SMTP disabled.
+          SMTP_RELAY_ADMIN_FROM: ${{ vars.TEST_SMTP_RELAY_ADMIN_FROM }}
+          ADMIN_EMAIL: ${{ vars.TEST_ADMIN_EMAIL }}
+          SMTP_RELAY_SERVICE_FROM: ${{ vars.TEST_SMTP_RELAY_SERVICE_FROM }}
+          SERVICE_EMAIL: ${{ vars.TEST_SERVICE_EMAIL }}
+          GRAFANA_SMTP_PORT: ${{ vars.GRAFANA_SMTP_PORT }}
+          GF_SMTP_ENABLED: ${{ vars.TEST_GF_SMTP_ENABLED }}
           # Canonical public origin for links in the email (this contour's URL);
           # required by the backend whenever SMTP_RELAY_HOST is set.
           PUBLIC_BASE_URL: ${{ vars.TEST_PUBLIC_BASE_URL }}
           GM_BASICAUTH_USER: ${{ vars.TEST_GM_BASICAUTH_USER }}
-          GRAFANA_ROOT_URL: ${{ vars.TEST_GRAFANA_ROOT_URL }}
           CADDY_SITE_ADDRESS: ${{ vars.TEST_CADDY_SITE_ADDRESS }}
-          TELEGRAM_MINIAPP_URL: ${{ vars.TEST_TELEGRAM_MINIAPP_URL }}
+          # TELEGRAM_MINIAPP_URL, GRAFANA_ROOT_URL and VITE_VK_ID_REDIRECT_URL are derived
+          # from PUBLIC_BASE_URL in the run step below, not stored as their own variables.
           TELEGRAM_GAME_CHANNEL_ID: ${{ vars.TEST_TELEGRAM_GAME_CHANNEL_ID }}
           TELEGRAM_CHAT_ID: ${{ vars.TEST_TELEGRAM_CHAT_ID }}
           TELEGRAM_SUPPORT_CHAT_ID: ${{ vars.TEST_TELEGRAM_SUPPORT_CHAT_ID }}
@@ -359,12 +377,16 @@ jobs:
           VITE_TELEGRAM_BOT_ID: ${{ vars.TEST_VITE_TELEGRAM_BOT_ID }}
           VITE_TELEGRAM_LINK: ${{ vars.TEST_VITE_TELEGRAM_LINK }}
           VITE_TELEGRAM_GAME_CHANNEL_NAME: ${{ vars.TEST_VITE_TELEGRAM_GAME_CHANNEL_NAME }}
-          VITE_VK_APP_LINK: ${{ vars.TEST_VITE_VK_APP_LINK }}
-          VITE_GATEWAY_URL: ${{ vars.TEST_VITE_GATEWAY_URL }}
-          # Unset vars render empty -> the compose ":-" defaults apply.
+          # VK Mini App landing link + VK ID "Web" app id: one value each serves every
+          # contour -> unprefixed. VITE_VK_APP_ID also feeds the gateway (GATEWAY_VK_ID_APP_ID);
+          # the VK ID redirect URL is derived from PUBLIC_BASE_URL in the run step below.
+          VITE_VK_APP_LINK: ${{ vars.VITE_VK_APP_LINK }}
+          VITE_VK_APP_ID: ${{ vars.VITE_VK_APP_ID }}
+          # VITE_GATEWAY_URL omitted: the SPA is served same-origin, so it stays the
+          # compose ":-" empty default. Other unset vars likewise fall to their defaults.
           POSTGRES_DB: ${{ vars.TEST_POSTGRES_DB }}
           POSTGRES_USER: ${{ vars.TEST_POSTGRES_USER }}
-          DICT_VERSION: ${{ vars.TEST_DICT_VERSION }}
+          DICT_VERSION: ${{ vars.DICT_VERSION }}
           LOG_LEVEL: ${{ vars.TEST_LOG_LEVEL }}
         run: |
           # Seed the config files to a stable host path. The runner checks out into
@@ -375,8 +397,34 @@ jobs:
           conf="$HOME/.scrabble-deploy"
           rm -rf "$conf"
           mkdir -p "$conf"
-          cp -r caddy otelcol prometheus tempo grafana "$conf"/
+          cp -r caddy otelcol prometheus tempo grafana blackbox "$conf"/
           export SCRABBLE_CONFIG_DIR="$conf"
+          # Maintenance page for the redeploy window, mirroring prod-deploy.sh so the SPA
+          # overlay is exercised on the test contour too (not only prod). Raised just before
+          # the recreate and lowered once caddy is back (below); the trap clears it if the
+          # step fails so the contour never sticks in maintenance (and the reseed above wipes a
+          # stale flag anyway). The caddy-routed probes run in the NEXT step, after it is lowered.
+          maint_flag="$conf/caddy/on"
+          trap 'rm -f "$maint_flag"' EXIT
+          # Derive the public URLs from the one canonical origin instead of storing each as
+          # its own variable (paths are structural SPA routes / the Caddy /_gm sub-path).
+          # Exported before build so the VK ID redirect is baked into the SPA.
+          base="${PUBLIC_BASE_URL%/}"
+          export TELEGRAM_MINIAPP_URL="$base/telegram/"
+          export GRAFANA_ROOT_URL="$base/_gm/grafana/"
+          export VITE_VK_ID_REDIRECT_URL="$base/app/"
+          # Grafana's SMTP from_address must be a BARE address (it rejects the "Name" <addr>
+          # form the backend go-mail accepts) and validates it even when SMTP is disabled — a
+          # bad value crash-loops Grafana. Split the display-format SERVICE From into a bare
+          # address + name for Grafana; the backend keeps the full form.
+          svc_from="${SMTP_RELAY_SERVICE_FROM:-}"
+          case "$svc_from" in
+            *"<"*">"*)
+              export GRAFANA_SMTP_FROM_ADDRESS="$(printf '%s' "$svc_from" | sed -E 's/.*<([^>]+)>.*/\1/')"
+              export GRAFANA_SMTP_FROM_NAME="$(printf '%s' "$svc_from" | sed -E 's/[[:space:]]*<[^>]*>.*$//; s/^"//; s/"$//')" ;;
+            *)
+              export GRAFANA_SMTP_FROM_ADDRESS="$svc_from" ;;
+          esac
           # Bot-link mTLS material for the test contour: a private CA + gateway/bot
           # leaves (CN=gateway, the service name the bot dials). Prod supplies these
           # from PROD_ secrets instead. Regenerated each deploy; both ends redeploy
@@ -389,12 +437,23 @@ jobs:
           # bot on its own host instead (deploy/docker-compose.bot.yml), and the prod
           # main host omits both. Without the profile they would not start here.
           docker compose --ansi never --profile telegram-local build --progress plain
+          # Raise the maintenance page, THEN bring caddy onto the reseeded config mount so it
+          # actually carries the flag: the running caddy sits on the stale pre-reseed mount (the
+          # dir was rm'd + recreated — see the force-recreate note below), so a flag written to
+          # the new dir is invisible until caddy is recreated. With the fresh caddy up, an open
+          # SPA sees the 503 marker + overlay for the whole recreate window, not a bare reconnect.
+          : > "$maint_flag"
+          docker compose --ansi never up -d --force-recreate --no-deps caddy
           docker compose --ansi never --profile telegram-local up -d --remove-orphans
           # The config-only services bind-mount the reseeded config dir. A plain `up -d`
           # leaves them on the previous bind mount (the dir was rm'd + recreated), so a
-          # changed Caddyfile or Grafana dashboard is ignored — force-recreate them to
-          # pick up the fresh config.
-          docker compose --ansi never up -d --force-recreate --no-deps caddy otelcol prometheus tempo grafana
+          # changed Grafana dashboard is ignored — force-recreate them to pick up the fresh
+          # config. (Caddy was already recreated above so it would carry the maintenance flag.)
+          docker compose --ansi never up -d --force-recreate --no-deps otelcol prometheus tempo grafana
+          # Lower the maintenance page: services are back. An open SPA's poll now gets through
+          # (once the gateway finishes booting) and reloads into the fresh client; the caddy
+          # probes in the next step see 200. The EXIT trap is a backstop if we failed earlier.
+          rm -f "$maint_flag"
 
       - name: Probe the landing, gateway and backend
         run: |

.gitea/workflows/prod-deploy.yaml

@@ -40,12 +40,22 @@ jobs:
       VITE_TELEGRAM_BOT_ID: ${{ vars.PROD_VITE_TELEGRAM_BOT_ID }}
       VITE_TELEGRAM_LINK: ${{ vars.PROD_VITE_TELEGRAM_LINK }}
       VITE_TELEGRAM_GAME_CHANNEL_NAME: ${{ vars.PROD_VITE_TELEGRAM_GAME_CHANNEL_NAME }}
-      VITE_VK_APP_LINK: ${{ vars.PROD_VITE_VK_APP_LINK }}
-      VITE_GATEWAY_URL: ${{ vars.PROD_VITE_GATEWAY_URL }}
+      # VK Mini App link + VK ID "Web" app id: one value each serves every contour.
+      VITE_VK_APP_LINK: ${{ vars.VITE_VK_APP_LINK }}
+      VITE_VK_APP_ID: ${{ vars.VITE_VK_APP_ID }}
+      # VITE_GATEWAY_URL omitted: the SPA is served same-origin (compose ":-" default).
       POSTGRES_PASSWORD: ${{ secrets.PROD_POSTGRES_PASSWORD }}
       GM_BASICAUTH_HASH: ${{ secrets.PROD_GM_BASICAUTH_HASH }}
-      TELEGRAM_MINIAPP_URL: ${{ vars.PROD_TELEGRAM_MINIAPP_URL }}
-      DICT_VERSION: ${{ vars.PROD_DICT_VERSION }}
+      # `docker compose build` interpolates the WHOLE compose file, so every :?-guarded
+      # runtime var must be present at build even though it is not a build-arg — incl. the
+      # backend's EXPORT_SIGN_KEY (added with the finished-game export after v1.7.0, which is
+      # why the first v1.8.0 build tripped on it). POSTGRES_PASSWORD/GM_BASICAUTH_HASH above
+      # are here for the same reason; DICT_VERSION + the derived Mini App URL cover the rest.
+      EXPORT_SIGN_KEY: ${{ secrets.PROD_EXPORT_SIGN_KEY }}
+      # PUBLIC_BASE_URL drives the derived VK ID redirect (baked into the SPA) and the
+      # Mini App URL; both are computed in the build step, not stored variables.
+      PUBLIC_BASE_URL: ${{ vars.PROD_PUBLIC_BASE_URL }}
+      DICT_VERSION: ${{ vars.DICT_VERSION }}
     steps:
       - uses: actions/checkout@v4
         with:
@@ -59,6 +69,11 @@ jobs:
         working-directory: deploy
         run: |
           export TAG="${{ steps.ver.outputs.tag }}" APP_VERSION="${{ steps.ver.outputs.tag }}" SCRABBLE_CONFIG_DIR=.
+          # Derive the public URLs from the one canonical origin: the VK ID redirect is a
+          # build-arg baked into the SPA, and the Mini App URL satisfies the (profiled-out)
+          # bot service's compose ":?" guard during parse. See deploy/write-prod-env.sh.
+          base="${PUBLIC_BASE_URL%/}"
+          export VITE_VK_ID_REDIRECT_URL="$base/app/" TELEGRAM_MINIAPP_URL="$base/telegram/"
           # The main-stack images via compose (reuses the build args, incl. VERSION);
           # the bot separately, since it is profiled out of the prod compose.
           docker compose -f docker-compose.yml -f docker-compose.prod.yml build
@@ -83,28 +98,45 @@ jobs:
       GM_BASICAUTH_HASH: ${{ secrets.PROD_GM_BASICAUTH_HASH }}
       GRAFANA_ADMIN_PASSWORD: ${{ secrets.PROD_GRAFANA_ADMIN_PASSWORD }}
       TELEGRAM_BOT_TOKEN: ${{ secrets.PROD_TELEGRAM_BOT_TOKEN }}
-      GATEWAY_VK_APP_SECRET: ${{ secrets.PROD_GATEWAY_VK_APP_SECRET }}
+      GATEWAY_VK_APP_SECRET: ${{ secrets.GATEWAY_VK_APP_SECRET }}
+      # VK ID web login: the "Web" app id (the gateway reuses it as GATEWAY_VK_ID_APP_ID at
+      # runtime) + the app's protected key. Both shared across contours. The redirect URL is
+      # derived from PUBLIC_BASE_URL in deploy/write-prod-env.sh.
+      VITE_VK_APP_ID: ${{ vars.VITE_VK_APP_ID }}
+      GATEWAY_VK_ID_CLIENT_SECRET: ${{ secrets.GATEWAY_VK_ID_CLIENT_SECRET }}
+      # Planted honeytoken bearer: presenting it earns a 24h IP ban + a high-severity alarm.
+      # Per-contour secret; empty = trap off. Rendered by deploy/write-prod-env.sh.
+      GATEWAY_HONEYTOKEN: ${{ secrets.PROD_GATEWAY_HONEYTOKEN }}
       # Signs the finished-game export download URLs (backend BACKEND_EXPORT_SIGN_KEY).
       EXPORT_SIGN_KEY: ${{ secrets.PROD_EXPORT_SIGN_KEY }}
-      # Transactional email via the shared Selectel relay (confirm-codes).
-      SMTP_RELAY_USER: ${{ secrets.PROD_SMTP_RELAY_USER }}
-      SMTP_RELAY_PASS: ${{ secrets.PROD_SMTP_RELAY_PASS }}
-      SMTP_RELAY_HOST: ${{ vars.PROD_SMTP_RELAY_HOST }}
-      SMTP_RELAY_PORT: ${{ vars.PROD_SMTP_RELAY_PORT }}
-      SMTP_RELAY_TLS: ${{ vars.PROD_SMTP_RELAY_TLS }}
+      # Transactional email via the shared Selectel relay (confirm-codes): one account for
+      # every contour -> unprefixed host/port/tls/user/pass.
+      SMTP_RELAY_USER: ${{ secrets.SMTP_RELAY_USER }}
+      SMTP_RELAY_PASS: ${{ secrets.SMTP_RELAY_PASS }}
+      SMTP_RELAY_HOST: ${{ vars.SMTP_RELAY_HOST }}
+      SMTP_RELAY_PORT: ${{ vars.SMTP_RELAY_PORT }}
+      SMTP_RELAY_TLS: ${{ vars.SMTP_RELAY_TLS }}
       SMTP_RELAY_FROM: ${{ vars.PROD_SMTP_RELAY_FROM }}
+      # Operator alerts: backend admin emails + Grafana infra alerts (distinct senders +
+      # recipients; Grafana uses the relay's STARTTLS host:port).
+      SMTP_RELAY_ADMIN_FROM: ${{ vars.PROD_SMTP_RELAY_ADMIN_FROM }}
+      ADMIN_EMAIL: ${{ vars.PROD_ADMIN_EMAIL }}
+      SMTP_RELAY_SERVICE_FROM: ${{ vars.PROD_SMTP_RELAY_SERVICE_FROM }}
+      SERVICE_EMAIL: ${{ vars.PROD_SERVICE_EMAIL }}
+      GRAFANA_SMTP_PORT: ${{ vars.GRAFANA_SMTP_PORT }}
+      GF_SMTP_ENABLED: ${{ vars.PROD_GF_SMTP_ENABLED }}
       PUBLIC_BASE_URL: ${{ vars.PROD_PUBLIC_BASE_URL }}
       PROD_BOTLINK_CA: ${{ secrets.PROD_BOTLINK_CA }}
       PROD_BOTLINK_GATEWAY_CERT: ${{ secrets.PROD_BOTLINK_GATEWAY_CERT }}
       PROD_BOTLINK_GATEWAY_KEY: ${{ secrets.PROD_BOTLINK_GATEWAY_KEY }}
       GM_BASICAUTH_USER: ${{ vars.PROD_GM_BASICAUTH_USER }}
-      GRAFANA_ROOT_URL: ${{ vars.PROD_GRAFANA_ROOT_URL }}
       CADDY_SITE_ADDRESS: ${{ vars.PROD_CADDY_SITE_ADDRESS }}
       LOG_LEVEL: ${{ vars.PROD_LOG_LEVEL }}
-      DICT_VERSION: ${{ vars.PROD_DICT_VERSION }}
+      DICT_VERSION: ${{ vars.DICT_VERSION }}
       POSTGRES_DB: ${{ vars.PROD_POSTGRES_DB }}
       POSTGRES_USER: ${{ vars.PROD_POSTGRES_USER }}
-      TELEGRAM_MINIAPP_URL: ${{ vars.PROD_TELEGRAM_MINIAPP_URL }}
+      # TELEGRAM_MINIAPP_URL and GRAFANA_ROOT_URL are derived from PUBLIC_BASE_URL in
+      # deploy/write-prod-env.sh, not stored variables.
     steps:
       - uses: actions/checkout@v4
         with:
@@ -132,33 +164,8 @@ jobs:
         run: |
           umask 077
           mkdir -p stage/certs-main
-          cat > stage/env.sh <<EOF
-          export REGISTRY='$REGISTRY'
-          export SCRABBLE_CONFIG_DIR='/opt/scrabble'
-          export POSTGRES_DB='${POSTGRES_DB:-scrabble}'
-          export POSTGRES_USER='${POSTGRES_USER:-scrabble}'
-          export POSTGRES_PASSWORD='$POSTGRES_PASSWORD'
-          export GM_BASICAUTH_USER='${GM_BASICAUTH_USER:-gm}'
-          export GM_BASICAUTH_HASH='$GM_BASICAUTH_HASH'
-          export GRAFANA_ADMIN_PASSWORD='$GRAFANA_ADMIN_PASSWORD'
-          export GRAFANA_ROOT_URL='$GRAFANA_ROOT_URL'
-          export CADDY_SITE_ADDRESS='$CADDY_SITE_ADDRESS'
-          export LOG_LEVEL='${LOG_LEVEL:-info}'
-          export DICT_VERSION='$DICT_VERSION'
-          export APP_VERSION='$TAG'
-          export TELEGRAM_BOT_TOKEN='$TELEGRAM_BOT_TOKEN'
-          export TELEGRAM_MINIAPP_URL='$TELEGRAM_MINIAPP_URL'
-          export GATEWAY_VK_APP_SECRET='$GATEWAY_VK_APP_SECRET'
-          export EXPORT_SIGN_KEY='$EXPORT_SIGN_KEY'
-          export SMTP_RELAY_HOST='$SMTP_RELAY_HOST'
-          export SMTP_RELAY_PORT='$SMTP_RELAY_PORT'
-          export SMTP_RELAY_TLS='$SMTP_RELAY_TLS'
-          export SMTP_RELAY_USER='$SMTP_RELAY_USER'
-          export SMTP_RELAY_PASS='$SMTP_RELAY_PASS'
-          export SMTP_RELAY_FROM='$SMTP_RELAY_FROM'
-          export PUBLIC_BASE_URL='$PUBLIC_BASE_URL'
-          export GATEWAY_ABUSE_BAN_ENABLED='true'
-          EOF
+          # Shared with prod-rollback so the two paths render an identical runtime env.
+          APP_VERSION="$TAG" bash deploy/write-prod-env.sh stage/env.sh
           printf '%s\n' "$PROD_BOTLINK_CA"           > stage/certs-main/ca.crt
           printf '%s\n' "$PROD_BOTLINK_GATEWAY_CERT" > stage/certs-main/gateway.crt
           printf '%s\n' "$PROD_BOTLINK_GATEWAY_KEY"  > stage/certs-main/gateway.key
@@ -169,7 +176,7 @@ jobs:
           ssh_main 'mkdir -p /opt/scrabble/compose'
           tar -C deploy -czf - docker-compose.yml docker-compose.prod.yml prod-deploy.sh \
             | ssh_main 'tar -C /opt/scrabble/compose -xzf -'
-          tar -C deploy -czf - caddy otelcol prometheus tempo grafana \
+          tar -C deploy -czf - caddy otelcol prometheus tempo grafana blackbox \
             | ssh_main 'tar -C /opt/scrabble -xzf -'
           tar -C stage -czf - certs-main \
             | ssh_main 'rm -rf /opt/scrabble/certs && mkdir -p /opt/scrabble/certs && tar -C /opt/scrabble/certs --strip-components=1 -xzf -'
@@ -197,7 +204,8 @@ jobs:
       PROD_BOTLINK_BOT_CERT: ${{ secrets.PROD_BOTLINK_BOT_CERT }}
       PROD_BOTLINK_BOT_KEY: ${{ secrets.PROD_BOTLINK_BOT_KEY }}
       LOG_LEVEL: ${{ vars.PROD_LOG_LEVEL }}
-      TELEGRAM_MINIAPP_URL: ${{ vars.PROD_TELEGRAM_MINIAPP_URL }}
+      # PUBLIC_BASE_URL drives the derived Mini App URL in deploy/write-prod-bot-env.sh.
+      PUBLIC_BASE_URL: ${{ vars.PROD_PUBLIC_BASE_URL }}
       TELEGRAM_GAME_CHANNEL_ID: ${{ vars.PROD_TELEGRAM_GAME_CHANNEL_ID }}
       TELEGRAM_CHAT_ID: ${{ vars.PROD_TELEGRAM_CHAT_ID }}
       TELEGRAM_SUPPORT_CHAT_ID: ${{ vars.PROD_TELEGRAM_SUPPORT_CHAT_ID }}
@@ -214,20 +222,8 @@ jobs:
         run: |
           umask 077
           mkdir -p stage/certs-bot
-          cat > stage/env.bot.sh <<EOF
-          export SCRABBLE_CONFIG_DIR='/opt/scrabble'
-          export BOT_IMAGE='$REGISTRY/scrabble-telegram-bot:$TAG'
-          export BOTLINK_GATEWAY_ADDR='$MAIN_HOST:9443'
-          export TELEGRAM_BOT_TOKEN='$TELEGRAM_BOT_TOKEN'
-          export TELEGRAM_MINIAPP_URL='$TELEGRAM_MINIAPP_URL'
-          export TELEGRAM_GAME_CHANNEL_ID='$TELEGRAM_GAME_CHANNEL_ID'
-          export TELEGRAM_CHAT_ID='$TELEGRAM_CHAT_ID'
-          export TELEGRAM_SUPPORT_CHAT_ID='$TELEGRAM_SUPPORT_CHAT_ID'
-          export TELEGRAM_PROMO_BOT_TOKEN='$TELEGRAM_PROMO_BOT_TOKEN'
-          export TELEGRAM_BOT_USERNAME='$TELEGRAM_BOT_USERNAME'
-          export TELEGRAM_BOT_LINK='$TELEGRAM_BOT_LINK'
-          export LOG_LEVEL='${LOG_LEVEL:-info}'
-          EOF
+          # Shared with prod-rollback so the two paths render an identical bot env.
+          BOT_IMAGE="$REGISTRY/scrabble-telegram-bot:$TAG" bash deploy/write-prod-bot-env.sh stage/env.bot.sh
           printf '%s\n' "$PROD_BOTLINK_CA"       > stage/certs-bot/ca.crt
           printf '%s\n' "$PROD_BOTLINK_BOT_CERT" > stage/certs-bot/bot.crt
           printf '%s\n' "$PROD_BOTLINK_BOT_KEY"  > stage/certs-bot/bot.key

.gitea/workflows/prod-rollback.yaml

@@ -51,13 +51,32 @@ jobs:
       PROD_BOTLINK_GATEWAY_CERT: ${{ secrets.PROD_BOTLINK_GATEWAY_CERT }}
       PROD_BOTLINK_GATEWAY_KEY: ${{ secrets.PROD_BOTLINK_GATEWAY_KEY }}
       GM_BASICAUTH_USER: ${{ vars.PROD_GM_BASICAUTH_USER }}
-      GRAFANA_ROOT_URL: ${{ vars.PROD_GRAFANA_ROOT_URL }}
       CADDY_SITE_ADDRESS: ${{ vars.PROD_CADDY_SITE_ADDRESS }}
       LOG_LEVEL: ${{ vars.PROD_LOG_LEVEL }}
-      DICT_VERSION: ${{ vars.PROD_DICT_VERSION }}
+      DICT_VERSION: ${{ vars.DICT_VERSION }}
       POSTGRES_DB: ${{ vars.PROD_POSTGRES_DB }}
       POSTGRES_USER: ${{ vars.PROD_POSTGRES_USER }}
-      TELEGRAM_MINIAPP_URL: ${{ vars.PROD_TELEGRAM_MINIAPP_URL }}
+      PUBLIC_BASE_URL: ${{ vars.PROD_PUBLIC_BASE_URL }}
+      # Full runtime env — parity with prod-deploy's deploy-main so a rollback re-renders
+      # the SAME env.sh (email / VK login / Grafana alerts survive a rollback). TELEGRAM_MINIAPP_URL
+      # and GRAFANA_ROOT_URL are derived from PUBLIC_BASE_URL in deploy/write-prod-env.sh.
+      GATEWAY_VK_APP_SECRET: ${{ secrets.GATEWAY_VK_APP_SECRET }}
+      VITE_VK_APP_ID: ${{ vars.VITE_VK_APP_ID }}
+      GATEWAY_VK_ID_CLIENT_SECRET: ${{ secrets.GATEWAY_VK_ID_CLIENT_SECRET }}
+      GATEWAY_HONEYTOKEN: ${{ secrets.PROD_GATEWAY_HONEYTOKEN }}
+      EXPORT_SIGN_KEY: ${{ secrets.PROD_EXPORT_SIGN_KEY }}
+      SMTP_RELAY_USER: ${{ secrets.SMTP_RELAY_USER }}
+      SMTP_RELAY_PASS: ${{ secrets.SMTP_RELAY_PASS }}
+      SMTP_RELAY_HOST: ${{ vars.SMTP_RELAY_HOST }}
+      SMTP_RELAY_PORT: ${{ vars.SMTP_RELAY_PORT }}
+      SMTP_RELAY_TLS: ${{ vars.SMTP_RELAY_TLS }}
+      SMTP_RELAY_FROM: ${{ vars.PROD_SMTP_RELAY_FROM }}
+      SMTP_RELAY_ADMIN_FROM: ${{ vars.PROD_SMTP_RELAY_ADMIN_FROM }}
+      ADMIN_EMAIL: ${{ vars.PROD_ADMIN_EMAIL }}
+      SMTP_RELAY_SERVICE_FROM: ${{ vars.PROD_SMTP_RELAY_SERVICE_FROM }}
+      SERVICE_EMAIL: ${{ vars.PROD_SERVICE_EMAIL }}
+      GRAFANA_SMTP_PORT: ${{ vars.GRAFANA_SMTP_PORT }}
+      GF_SMTP_ENABLED: ${{ vars.PROD_GF_SMTP_ENABLED }}
       INPUT_TARGET: ${{ inputs.target_version }}
     steps:
       - uses: actions/checkout@v4
@@ -89,24 +108,9 @@ jobs:
         run: |
           umask 077
           mkdir -p stage/certs-main
-          cat > stage/env.sh <<EOF
-          export REGISTRY='$REGISTRY'
-          export SCRABBLE_CONFIG_DIR='/opt/scrabble'
-          export POSTGRES_DB='${POSTGRES_DB:-scrabble}'
-          export POSTGRES_USER='${POSTGRES_USER:-scrabble}'
-          export POSTGRES_PASSWORD='$POSTGRES_PASSWORD'
-          export GM_BASICAUTH_USER='${GM_BASICAUTH_USER:-gm}'
-          export GM_BASICAUTH_HASH='$GM_BASICAUTH_HASH'
-          export GRAFANA_ADMIN_PASSWORD='$GRAFANA_ADMIN_PASSWORD'
-          export GRAFANA_ROOT_URL='$GRAFANA_ROOT_URL'
-          export CADDY_SITE_ADDRESS='$CADDY_SITE_ADDRESS'
-          export LOG_LEVEL='${LOG_LEVEL:-info}'
-          export DICT_VERSION='$DICT_VERSION'
-          export APP_VERSION='$TARGET'
-          export TELEGRAM_BOT_TOKEN='$TELEGRAM_BOT_TOKEN'
-          export TELEGRAM_MINIAPP_URL='$TELEGRAM_MINIAPP_URL'
-          export GATEWAY_ABUSE_BAN_ENABLED='true'
-          EOF
+          # Same writer as prod-deploy's deploy-main -> the rollback re-renders the FULL
+          # runtime env (not a subset), so email / VK login / Grafana alerts survive it.
+          APP_VERSION="$TARGET" bash deploy/write-prod-env.sh stage/env.sh
           printf '%s\n' "$PROD_BOTLINK_CA"           > stage/certs-main/ca.crt
           printf '%s\n' "$PROD_BOTLINK_GATEWAY_CERT" > stage/certs-main/gateway.crt
           printf '%s\n' "$PROD_BOTLINK_GATEWAY_KEY"  > stage/certs-main/gateway.key
@@ -147,9 +151,11 @@ jobs:
       PROD_BOTLINK_BOT_CERT: ${{ secrets.PROD_BOTLINK_BOT_CERT }}
       PROD_BOTLINK_BOT_KEY: ${{ secrets.PROD_BOTLINK_BOT_KEY }}
       LOG_LEVEL: ${{ vars.PROD_LOG_LEVEL }}
-      TELEGRAM_MINIAPP_URL: ${{ vars.PROD_TELEGRAM_MINIAPP_URL }}
+      # PUBLIC_BASE_URL drives the derived Mini App URL; SUPPORT_CHAT_ID for parity with deploy.
+      PUBLIC_BASE_URL: ${{ vars.PROD_PUBLIC_BASE_URL }}
       TELEGRAM_GAME_CHANNEL_ID: ${{ vars.PROD_TELEGRAM_GAME_CHANNEL_ID }}
       TELEGRAM_CHAT_ID: ${{ vars.PROD_TELEGRAM_CHAT_ID }}
+      TELEGRAM_SUPPORT_CHAT_ID: ${{ vars.PROD_TELEGRAM_SUPPORT_CHAT_ID }}
       TELEGRAM_BOT_USERNAME: ${{ vars.PROD_TELEGRAM_BOT_USERNAME }}
       TELEGRAM_BOT_LINK: ${{ vars.PROD_VITE_TELEGRAM_LINK }}
     steps:
@@ -163,19 +169,8 @@ jobs:
         run: |
           umask 077
           mkdir -p stage/certs-bot
-          cat > stage/env.bot.sh <<EOF
-          export SCRABBLE_CONFIG_DIR='/opt/scrabble'
-          export BOT_IMAGE='$REGISTRY/scrabble-telegram-bot:$TARGET'
-          export BOTLINK_GATEWAY_ADDR='$MAIN_HOST:9443'
-          export TELEGRAM_BOT_TOKEN='$TELEGRAM_BOT_TOKEN'
-          export TELEGRAM_MINIAPP_URL='$TELEGRAM_MINIAPP_URL'
-          export TELEGRAM_GAME_CHANNEL_ID='$TELEGRAM_GAME_CHANNEL_ID'
-          export TELEGRAM_CHAT_ID='$TELEGRAM_CHAT_ID'
-          export TELEGRAM_PROMO_BOT_TOKEN='$TELEGRAM_PROMO_BOT_TOKEN'
-          export TELEGRAM_BOT_USERNAME='$TELEGRAM_BOT_USERNAME'
-          export TELEGRAM_BOT_LINK='$TELEGRAM_BOT_LINK'
-          export LOG_LEVEL='${LOG_LEVEL:-info}'
-          EOF
+          # Same writer as prod-deploy's deploy-bot (parity; includes TELEGRAM_SUPPORT_CHAT_ID).
+          BOT_IMAGE="$REGISTRY/scrabble-telegram-bot:$TARGET" bash deploy/write-prod-bot-env.sh stage/env.bot.sh
           printf '%s\n' "$PROD_BOTLINK_CA"       > stage/certs-bot/ca.crt
           printf '%s\n' "$PROD_BOTLINK_BOT_CERT" > stage/certs-bot/bot.crt
           printf '%s\n' "$PROD_BOTLINK_BOT_KEY"  > stage/certs-bot/bot.key

backend/cmd/backend/main.go

@@ -12,6 +12,7 @@ import (
 	"fmt"
 	"log"
 	"os/signal"
+	"strings"
 	"syscall"
 	"time"
 
@@ -20,6 +21,7 @@ import (
 
 	"scrabble/backend/internal/account"
 	"scrabble/backend/internal/accountmerge"
+	"scrabble/backend/internal/adminalert"
 	"scrabble/backend/internal/ads"
 	"scrabble/backend/internal/banview"
 	"scrabble/backend/internal/config"
@@ -44,6 +46,10 @@ import (
 // telemetryShutdownTimeout bounds the OpenTelemetry flush during process exit.
 const telemetryShutdownTimeout = 5 * time.Second
 
+// adminAlertInterval is how often the operator-alert worker checks for new feedback /
+// complaints; a burst within one interval coalesces into a single digest email.
+const adminAlertInterval = 5 * time.Minute
+
 func main() {
 	cfg, err := config.Load()
 	if err != nil {
@@ -162,6 +168,15 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 		zap.Duration("interval", cfg.GuestReapInterval),
 		zap.Duration("retention", cfg.GuestRetention))
 
+	// Purge the account-deletion legal dossier past its retention TTL: the
+	// retained-identities journal, and the feedback thread + dossier PII of long-deleted
+	// accounts (chat is kept). Checked daily; the TTL is a two-year policy constant.
+	retentionReaper := account.NewRetentionReaper(accounts, account.RetentionTTL, logger)
+	go retentionReaper.Run(ctx, 24*time.Hour)
+	logger.Info("retention reaper started",
+		zap.Duration("interval", 24*time.Hour),
+		zap.Duration("retention", account.RetentionTTL))
+
 	// Re-evaluate moderated-chat write access when a temporary block self-expires:
 	// no operator action fires then, so the sweeper emits the chat-access-changed
 	// event for lapsed blocks and the gateway re-pushes the chat-gate command.
@@ -198,6 +213,18 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 	feedbackSvc := feedback.NewService(feedback.NewStore(db), accounts)
 	feedbackSvc.SetNotifier(hub)
 
+	// Operator alert emails on new feedback / word complaints, coalesced into one digest
+	// per interval. Inert unless a distinct admin sender and recipient are configured.
+	if cfg.SMTP.AdminFrom != "" && cfg.SMTP.AdminTo != "" {
+		consoleURL := ""
+		if cfg.PublicBaseURL != "" {
+			consoleURL = strings.TrimRight(cfg.PublicBaseURL, "/") + "/_gm"
+		}
+		alerts := adminalert.New(mailer, feedbackSvc, games, cfg.SMTP.AdminFrom, cfg.SMTP.AdminTo, consoleURL, logger)
+		go alerts.Run(ctx, adminAlertInterval)
+		logger.Info("admin alert worker started", zap.Duration("interval", adminAlertInterval))
+	}
+
 	// Robot opponent: provision its durable account pool (a hard startup
 	// dependency, like the dictionaries) and start its move driver. The matchmaker
 	// substitutes a pooled robot for a missing human after the wait window.

backend/internal/account/email.go

@@ -35,12 +35,14 @@ const (
 )
 
 // Confirmation purposes recorded on a pending confirm-code row. They select what
-// verifying the code or the deeplink token does: sign in (login) or link/confirm the
-// address on the current account (link). Email change and account deletion add
-// further purposes in later stages.
+// verifying the code or the deeplink token does: sign in (login), link/confirm the
+// address on the current account (link), or replace the account's confirmed email with
+// a new address (change). Account deletion adds a further purpose in a later stage.
 const (
 	purposeLogin  = "login"
 	purposeLink   = "link"
+	purposeChange = "change"
+	purposeDelete = "delete"
 )
 
 // Errors returned by the email confirm-code flow.
@@ -64,6 +66,9 @@ var (
 	// ErrTooManyRequests is returned when confirm-code sends to an address are being
 	// requested too frequently (the resend cooldown or the rolling-hour cap).
 	ErrTooManyRequests = errors.New("account: too many code requests")
+	// ErrNoEmail is returned when an email-code step-up is requested for an account that
+	// holds no confirmed email (the caller must use the typed-phrase path instead).
+	ErrNoEmail = errors.New("account: no confirmed email")
 )
 
 // EmailService runs the email confirm-code flow: it issues a 6-digit code over a
@@ -114,7 +119,14 @@ func (s *EmailService) issueCode(ctx context.Context, accountID uuid.UUID, email
 	if err := s.store.replacePendingConfirmation(ctx, accountID, email, codeHash, tokenHash, purpose, s.now().Add(emailCodeTTL)); err != nil {
 		return err
 	}
-	msg, err := renderConfirmationEmail(purpose, code, s.confirmURL(token), s.baseURL, locale)
+	// Account deletion is never a one-tap link (a prefetch or a stray click must not delete
+	// an account): the delete code is entered in the app only, so the email omits the
+	// deeplink and ConfirmByToken refuses a delete token.
+	deeplink := s.confirmURL(token, locale)
+	if purpose == purposeDelete {
+		deeplink = ""
+	}
+	msg, err := renderConfirmationEmail(purpose, code, deeplink, s.baseURL, locale)
 	if err != nil {
 		return err
 	}
@@ -122,13 +134,14 @@ func (s *EmailService) issueCode(ctx context.Context, accountID uuid.UUID, email
 	return s.mailer.Send(ctx, msg)
 }
 
-// confirmURL builds the absolute one-tap confirm deeplink for token, or "" when no
-// public base URL is configured.
-func (s *EmailService) confirmURL(token string) string {
+// confirmURL builds the absolute one-tap confirm deeplink for token in locale, or ""
+// when no public base URL is configured. The locale rides the fragment as ?lang so the
+// confirm screen (opened in a browser with no session) renders in the email's language.
+func (s *EmailService) confirmURL(token, locale string) string {
 	if s.baseURL == "" {
 		return ""
 	}
-	return strings.TrimRight(s.baseURL, "/") + emailConfirmPath + token
+	return strings.TrimRight(s.baseURL, "/") + emailConfirmPath + token + "?lang=" + normalizeLocale(locale)
 }
 
 // accountLocale returns the account's preferred UI language for localising email,
@@ -193,6 +206,11 @@ func (s *EmailService) ConfirmCode(ctx context.Context, accountID uuid.UUID, ema
 	if err := s.store.confirmEmailIdentity(ctx, conf.id, accountID, addr, s.now()); err != nil {
 		return Account{}, err
 	}
+	// Binding the first confirmed email promotes a guest to a durable account, matching the
+	// link and deeplink flows (defence-in-depth: no confirmed-email path leaves is_guest set).
+	if err := s.store.ClearGuest(ctx, accountID); err != nil {
+		return Account{}, err
+	}
 	return s.store.GetByID(ctx, accountID)
 }
 
@@ -325,6 +343,29 @@ func (s *EmailService) ConfirmByToken(ctx context.Context, token string) (LinkCo
 			return LinkConfirmation{}, err
 		}
 		return LinkConfirmation{Purpose: purposeLink, Account: pend.accountID}, nil
+	case purposeChange:
+		owner, ok, err := s.store.confirmedEmailAccount(ctx, pend.email)
+		if err != nil {
+			return LinkConfirmation{}, err
+		}
+		if ok && owner != pend.accountID {
+			// The new address is confirmed by a different account: refuse without
+			// disclosing it (anti-enumeration). Unlike a link, a change never merges.
+			return LinkConfirmation{}, ErrEmailTaken
+		}
+		if ok && owner == pend.accountID {
+			if err := s.store.consumeConfirmation(ctx, pend.id, s.now()); err != nil {
+				return LinkConfirmation{}, err
+			}
+			return LinkConfirmation{Purpose: purposeChange, Account: pend.accountID}, nil
+		}
+		if err := s.store.replaceEmailIdentity(ctx, pend.id, pend.accountID, pend.email, s.now()); err != nil {
+			return LinkConfirmation{}, err
+		}
+		return LinkConfirmation{Purpose: purposeChange, Account: pend.accountID}, nil
+	case purposeDelete:
+		// Deletion is confirmed in the app with the code, never via a one-tap link.
+		return LinkConfirmation{}, fmt.Errorf("account: deletion cannot be confirmed by link")
 	default:
 		return LinkConfirmation{}, fmt.Errorf("account: unsupported confirmation purpose %q", pend.purpose)
 	}
@@ -358,6 +399,27 @@ func (s *Store) confirmedEmailAccount(ctx context.Context, email string) (uuid.U
 	return row.AccountID, true, nil
 }
 
+// confirmedEmailOf returns the account's confirmed email address and true, or ("", false)
+// when it holds none. It backs the deletion step-up, which mails a code to the account's
+// own address.
+func (s *Store) confirmedEmailOf(ctx context.Context, accountID uuid.UUID) (string, bool, error) {
+	stmt := postgres.SELECT(table.Identities.ExternalID).
+		FROM(table.Identities).
+		WHERE(
+			table.Identities.AccountID.EQ(postgres.UUID(accountID)).
+				AND(table.Identities.Kind.EQ(postgres.String(KindEmail))).
+				AND(table.Identities.Confirmed.EQ(postgres.Bool(true))),
+		).LIMIT(1)
+	var row model.Identities
+	if err := stmt.QueryContext(ctx, s.db, &row); err != nil {
+		if errors.Is(err, qrm.ErrNoRows) {
+			return "", false, nil
+		}
+		return "", false, fmt.Errorf("account: confirmed email of %s: %w", accountID, err)
+	}
+	return row.ExternalID, true, nil
+}
+
 // replacePendingConfirmation clears any pending code for (accountID, email) and
 // inserts a fresh one, inside one transaction.
 func (s *Store) replacePendingConfirmation(ctx context.Context, accountID uuid.UUID, email, codeHash, linkTokenHash, purpose string, expiresAt time.Time) error {
@@ -505,6 +567,69 @@ func (s *Store) confirmEmailIdentity(ctx context.Context, confirmationID, accoun
 	return nil
 }
 
+// replaceEmailIdentity consumes the confirmation, deletes the account's existing email
+// identity (freeing the old address) and inserts newEmail as its confirmed email, inside
+// one transaction. It backs the change-email flow. A unique-constraint violation — the
+// new address was confirmed elsewhere in the meantime — surfaces as ErrEmailTaken. When
+// the account holds no email identity yet the delete is a no-op, so this doubles as an
+// attach.
+func (s *Store) replaceEmailIdentity(ctx context.Context, confirmationID, accountID uuid.UUID, newEmail string, now time.Time) error {
+	identityID, err := uuid.NewV7()
+	if err != nil {
+		return fmt.Errorf("account: new identity id: %w", err)
+	}
+	err = withTx(ctx, s.db, func(tx *sql.Tx) error {
+		upd := table.EmailConfirmations.
+			UPDATE(table.EmailConfirmations.ConsumedAt).
+			SET(postgres.TimestampzT(now)).
+			WHERE(table.EmailConfirmations.ConfirmationID.EQ(postgres.UUID(confirmationID)))
+		if _, err := upd.ExecContext(ctx, tx); err != nil {
+			return fmt.Errorf("consume confirmation: %w", err)
+		}
+		// Journal the outgoing email before replacing it, so the legal dossier keeps the
+		// address the account used to hold (see retention.go).
+		var old model.Identities
+		sel := postgres.SELECT(
+			table.Identities.ExternalID, table.Identities.Confirmed, table.Identities.CreatedAt,
+		).FROM(table.Identities).WHERE(
+			table.Identities.AccountID.EQ(postgres.UUID(accountID)).
+				AND(table.Identities.Kind.EQ(postgres.String(KindEmail))),
+		).LIMIT(1)
+		switch err := sel.QueryContext(ctx, tx, &old); {
+		case err == nil:
+			if err := retainIdentityTx(ctx, tx, accountID, KindEmail, old.ExternalID, old.Confirmed, old.CreatedAt, retainChange); err != nil {
+				return err
+			}
+		case errors.Is(err, qrm.ErrNoRows):
+			// No prior email (this doubles as an attach); nothing to retain.
+		default:
+			return fmt.Errorf("load outgoing email identity: %w", err)
+		}
+		del := table.Identities.DELETE().WHERE(
+			table.Identities.AccountID.EQ(postgres.UUID(accountID)).
+				AND(table.Identities.Kind.EQ(postgres.String(KindEmail))),
+		)
+		if _, err := del.ExecContext(ctx, tx); err != nil {
+			return fmt.Errorf("delete old email identity: %w", err)
+		}
+		ins := table.Identities.INSERT(
+			table.Identities.IdentityID, table.Identities.AccountID, table.Identities.Kind,
+			table.Identities.ExternalID, table.Identities.Confirmed,
+		).VALUES(identityID, accountID, KindEmail, newEmail, true)
+		if _, err := ins.ExecContext(ctx, tx); err != nil {
+			return err
+		}
+		return nil
+	})
+	if err != nil {
+		if isUniqueViolation(err) {
+			return ErrEmailTaken
+		}
+		return fmt.Errorf("account: replace email identity: %w", err)
+	}
+	return nil
+}
+
 // confirmEmailLogin consumes the login code and marks the existing email
 // identity confirmed, inside one transaction. The identity already exists (a
 // login provisioned it), so this updates rather than inserts and is idempotent

backend/internal/account/emailtemplate.go

@@ -80,6 +80,42 @@ var confirmEmailCopy = map[string]map[string]emailCopy{
 			FooterIgnore: "Если вы не запрашивали это письмо, просто проигнорируйте его.",
 		},
 	},
+	purposeChange: {
+		"en": {
+			Subject:      "Confirm your new Erudit e-mail",
+			Preheader:    "Confirm your new address",
+			Heading:      "Confirm your new e-mail",
+			Intro:        "Enter this code to switch your account to this address:",
+			CTALabel:     "Confirm with one tap",
+			FooterIgnore: "If you didn't request this change, you can safely ignore it — your address stays the same.",
+		},
+		"ru": {
+			Subject:      "Подтвердите новый e-mail в Эрудит",
+			Preheader:    "Подтвердите новый адрес",
+			Heading:      "Смена e-mail",
+			Intro:        "Введите этот код, чтобы привязать аккаунт к новому адресу:",
+			CTALabel:     "Подтвердить одним нажатием",
+			FooterIgnore: "Если вы не запрашивали смену, просто проигнорируйте письмо — адрес останется прежним.",
+		},
+	},
+	purposeDelete: {
+		"en": {
+			Subject:      "Confirm your Erudit account deletion",
+			Preheader:    "Confirm account deletion",
+			Heading:      "Delete your account",
+			Intro:        "Enter this code in the app to permanently delete your account:",
+			CTALabel:     "",
+			FooterIgnore: "If you didn't request this, ignore it — your account stays as it is.",
+		},
+		"ru": {
+			Subject:      "Подтвердите удаление аккаунта Эрудит",
+			Preheader:    "Подтверждение удаления аккаунта",
+			Heading:      "Удаление аккаунта",
+			Intro:        "Введите этот код в приложении, чтобы удалить аккаунт без восстановления:",
+			CTALabel:     "",
+			FooterIgnore: "Если вы не запрашивали удаление, проигнорируйте письмо — аккаунт останется.",
+		},
+	},
 }
 
 // emailBrand is the brand wordmark per locale.

backend/internal/account/emailtemplate_test.go

@@ -16,6 +16,8 @@ func TestRenderConfirmationEmail(t *testing.T) {
 		{"login en", purposeLogin, "en", "sign-in"},
 		{"link ru", purposeLink, "ru", "подтвержд"},
 		{"link en", purposeLink, "en", "confirmation"},
+		{"change ru", purposeChange, "ru", "новый"},
+		{"change en", purposeChange, "en", "new"},
 	}
 	for _, c := range cases {
 		t.Run(c.name, func(t *testing.T) {

backend/internal/account/link.go

@@ -2,6 +2,7 @@ package account
 
 import (
 	"context"
+	"database/sql"
 	"errors"
 	"fmt"
 	"time"
@@ -16,6 +17,68 @@ import (
 // belongs to another account; the caller turns it into a merge.
 var ErrIdentityTaken = errors.New("account: identity already linked to another account")
 
+// ErrLastIdentity is returned when removing an identity would leave the account with
+// none, making it unreachable after logout. The admin email-erase refuses it.
+var ErrLastIdentity = errors.New("account: cannot remove the last identity")
+
+// RemoveIdentity deletes the account's identity of the given kind (and, for an email,
+// any pending confirmations for it), freeing it for reuse. It refuses when that is the
+// account's only identity (ErrLastIdentity) — which would leave the account
+// unreachable — and returns ErrNotFound when the account has no identity of that kind.
+// It backs the profile Unlink control and the admin "erase email" action.
+func (s *Store) RemoveIdentity(ctx context.Context, accountID uuid.UUID, kind string) error {
+	ids, err := s.Identities(ctx, accountID)
+	if err != nil {
+		return err
+	}
+	var toRetain []Identity
+	others := 0
+	for _, id := range ids {
+		if id.Kind == kind {
+			toRetain = append(toRetain, id)
+		} else {
+			others++
+		}
+	}
+	if len(toRetain) == 0 {
+		return ErrNotFound
+	}
+	if others == 0 {
+		return ErrLastIdentity
+	}
+	return withTx(ctx, s.db, func(tx *sql.Tx) error {
+		// Journal the detached credential before removing it, so the legal dossier
+		// survives while the identity frees for reuse (see retention.go).
+		for _, id := range toRetain {
+			if err := retainIdentityTx(ctx, tx, accountID, id.Kind, id.ExternalID, id.Confirmed, id.CreatedAt, retainUnlink); err != nil {
+				return err
+			}
+		}
+		delID := table.Identities.DELETE().WHERE(
+			table.Identities.AccountID.EQ(postgres.UUID(accountID)).
+				AND(table.Identities.Kind.EQ(postgres.String(kind))),
+		)
+		if _, err := delID.ExecContext(ctx, tx); err != nil {
+			return fmt.Errorf("account: delete %s identity %s: %w", kind, accountID, err)
+		}
+		if kind == KindEmail {
+			delConf := table.EmailConfirmations.DELETE().WHERE(
+				table.EmailConfirmations.AccountID.EQ(postgres.UUID(accountID)),
+			)
+			if _, err := delConf.ExecContext(ctx, tx); err != nil {
+				return fmt.Errorf("account: delete email confirmations %s: %w", accountID, err)
+			}
+		}
+		return nil
+	})
+}
+
+// RemoveEmailIdentity erases the account's email identity. It backs the admin console's
+// "erase email" action; the user-facing profile never unlinks email (it is changed).
+func (s *Store) RemoveEmailIdentity(ctx context.Context, accountID uuid.UUID) error {
+	return s.RemoveIdentity(ctx, accountID, KindEmail)
+}
+
 // RequestLinkCode issues and mails a confirm-code for email to accountID,
 // replacing any prior pending code. Unlike RequestCode it never refuses up front
 // (taken or already-confirmed): possession of the address is the authorization for
@@ -64,6 +127,100 @@ func (s *EmailService) ConfirmLink(ctx context.Context, accountID uuid.UUID, ema
 	return accountID, true, nil
 }
 
+// RequestChangeCode issues and mails a confirm-code to newEmail for an authenticated
+// email change on accountID, replacing any prior pending code. Like RequestLinkCode it
+// never refuses up front on "taken" (anti-enumeration): possession of newEmail is the
+// authorization, and a conflict with another account is revealed only at confirm — as a
+// non-disclosing refusal, never a merge.
+func (s *EmailService) RequestChangeCode(ctx context.Context, accountID uuid.UUID, newEmail string) error {
+	addr, err := normalizeEmail(newEmail)
+	if err != nil {
+		return err
+	}
+	if !s.allowSend(addr) {
+		return ErrTooManyRequests
+	}
+	return s.issueCode(ctx, accountID, addr, purposeChange, s.accountLocale(ctx, accountID))
+}
+
+// ConfirmChange verifies code for (accountID, newEmail) and atomically replaces the
+// account's confirmed email with newEmail, freeing the old address. When newEmail is
+// already confirmed by another account it refuses with ErrEmailTaken (surfaced to the
+// user as a non-disclosing "check the address or contact support"), never merging; when
+// the account already owns newEmail it is an idempotent no-op. It returns the usual
+// confirm-code errors (ErrNoPendingCode, ErrCodeExpired, ErrTooManyAttempts,
+// ErrCodeMismatch) and the updated account on success.
+func (s *EmailService) ConfirmChange(ctx context.Context, accountID uuid.UUID, newEmail, code string) (Account, error) {
+	addr, err := normalizeEmail(newEmail)
+	if err != nil {
+		return Account{}, err
+	}
+	conf, err := s.verifyPendingCode(ctx, accountID, addr, code)
+	if err != nil {
+		return Account{}, err
+	}
+	owner, ok, err := s.store.confirmedEmailAccount(ctx, addr)
+	if err != nil {
+		return Account{}, err
+	}
+	if ok && owner != accountID {
+		return Account{}, ErrEmailTaken
+	}
+	if ok && owner == accountID {
+		if err := s.store.consumeConfirmation(ctx, conf.id, s.now()); err != nil {
+			return Account{}, err
+		}
+		return s.store.GetByID(ctx, accountID)
+	}
+	if err := s.store.replaceEmailIdentity(ctx, conf.id, accountID, addr, s.now()); err != nil {
+		return Account{}, err
+	}
+	return s.store.GetByID(ctx, accountID)
+}
+
+// HasEmail reports whether accountID owns a confirmed email. The account-deletion step-up
+// mails a confirm-code when it does, and falls back to a typed phrase otherwise.
+func (s *EmailService) HasEmail(ctx context.Context, accountID uuid.UUID) (bool, error) {
+	_, ok, err := s.store.confirmedEmailOf(ctx, accountID)
+	return ok, err
+}
+
+// RequestDeleteCode mails an account-deletion confirm-code to the account's own confirmed
+// email (no deeplink — deletion is confirmed in the app). It returns ErrNoEmail when the
+// account holds no email, ErrTooManyRequests when throttled.
+func (s *EmailService) RequestDeleteCode(ctx context.Context, accountID uuid.UUID) error {
+	addr, ok, err := s.store.confirmedEmailOf(ctx, accountID)
+	if err != nil {
+		return err
+	}
+	if !ok {
+		return ErrNoEmail
+	}
+	if !s.allowSend(addr) {
+		return ErrTooManyRequests
+	}
+	return s.issueCode(ctx, accountID, addr, purposeDelete, s.accountLocale(ctx, accountID))
+}
+
+// VerifyDeleteCode verifies the account-deletion code against the account's own email and
+// consumes it on success. It returns ErrNoEmail (no email), the usual confirm-code errors
+// (ErrNoPendingCode, ErrCodeExpired, ErrTooManyAttempts, ErrCodeMismatch), or nil when the
+// code is valid — the caller then performs the deletion.
+func (s *EmailService) VerifyDeleteCode(ctx context.Context, accountID uuid.UUID, code string) error {
+	addr, ok, err := s.store.confirmedEmailOf(ctx, accountID)
+	if err != nil {
+		return err
+	}
+	if !ok {
+		return ErrNoEmail
+	}
+	conf, err := s.verifyPendingCode(ctx, accountID, addr, code)
+	if err != nil {
+		return err
+	}
+	return s.store.consumeConfirmation(ctx, conf.id, s.now())
+}
+
 // verifyPendingCode loads and checks the pending confirm-code for (accountID,
 // addr), counting a wrong attempt. It returns the confirmation on success.
 func (s *EmailService) verifyPendingCode(ctx context.Context, accountID uuid.UUID, addr, code string) (emailConfirmation, error) {

backend/internal/account/mailer.go

@@ -15,7 +15,11 @@ import (
 // required plain-text body and doubles as the multipart/alternative fallback;
 // HTML, when non-empty, is the preferred body a capable client renders instead.
 type Message struct {
+	// To is the recipient address, or several comma-separated (all get the one message).
 	To string
+	// From, when non-empty, overrides the configured sender for this message — the admin
+	// alert path uses a distinct From from the user-facing confirm-code sender.
+	From    string
 	Subject string
 	Text    string
 	HTML    string
@@ -29,6 +33,18 @@ type Mailer interface {
 	Send(ctx context.Context, msg Message) error
 }
 
+// splitAddrs splits a comma-separated recipient list into trimmed, non-empty addresses.
+func splitAddrs(list string) []string {
+	parts := strings.Split(list, ",")
+	out := make([]string, 0, len(parts))
+	for _, p := range parts {
+		if a := strings.TrimSpace(p); a != "" {
+			out = append(out, a)
+		}
+	}
+	return out
+}
+
 // SMTPConfig configures the SMTP relay. An empty Host selects the LogMailer
 // instead, so a deployment without a relay still runs (the code lands in the log).
 // TLS is always used and no client certificate is required — only the server
@@ -44,6 +60,11 @@ type SMTPConfig struct {
 	// port (implicit TLS on 465, STARTTLS otherwise); set it explicitly for a relay on
 	// a non-standard port (e.g. Selectel's 1127 = SSL, 1126 = STARTTLS).
 	TLS string
+	// AdminFrom / AdminTo drive the operator alert emails (new feedback / word complaints),
+	// distinct from the user-facing confirm-code sender. AdminTo may be several
+	// comma-separated addresses. Both empty disables the alert worker.
+	AdminFrom string
+	AdminTo   string
 }
 
 const (
@@ -110,10 +131,16 @@ func (m SMTPMailer) Send(ctx context.Context, msg Message) error {
 		return fmt.Errorf("account: build mail client: %w", err)
 	}
 	out := mail.NewMsg()
-	if err := out.From(m.cfg.From); err != nil {
-		return fmt.Errorf("account: set From %q: %w", m.cfg.From, err)
+	from := m.cfg.From
+	if msg.From != "" {
+		from = msg.From
 	}
-	if err := out.To(msg.To); err != nil {
+	if err := out.From(from); err != nil {
+		return fmt.Errorf("account: set From %q: %w", from, err)
+	}
+	// To may carry several comma-separated recipients; go-mail wants them as separate
+	// arguments (a single joined string parses as one malformed address).
+	if err := out.To(splitAddrs(msg.To)...); err != nil {
 		return fmt.Errorf("account: set To %q: %w", msg.To, err)
 	}
 	out.Subject(msg.Subject)

backend/internal/account/mailer_test.go

@@ -1,6 +1,28 @@
 package account
 
-import "testing"
+import (
+	"slices"
+	"testing"
+)
+
+// TestSplitAddrs covers the comma-separated recipient parsing used for the admin alert
+// To (several operator mailboxes in one message), including trimming and empty entries.
+func TestSplitAddrs(t *testing.T) {
+	cases := []struct {
+		in   string
+		want []string
+	}{
+		{"a@x.ru", []string{"a@x.ru"}},
+		{"a@x.ru, b@y.ru", []string{"a@x.ru", "b@y.ru"}},
+		{" a@x.ru ,, b@y.ru ,", []string{"a@x.ru", "b@y.ru"}},
+		{"", nil},
+	}
+	for _, c := range cases {
+		if got := splitAddrs(c.in); !slices.Equal(got, c.want) {
+			t.Errorf("splitAddrs(%q) = %v, want %v", c.in, got, c.want)
+		}
+	}
+}
 
 // TestSMTPTLSMode covers the explicit TLS mode and the port-based fallback, including
 // the non-standard Selectel ports (1127 = SSL, 1126 = STARTTLS) that the 465 heuristic

backend/internal/account/retention.go

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

backend/internal/account/userlist.go

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

backend/internal/accountdelete/delete.go

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

backend/internal/accountmerge/merge.go

@@ -27,6 +27,11 @@ import (
 // without taking a dependency on the game package.
 const statusActive = "active"
 
+// retainReasonMerge is the retained_identities.reason for a credential dropped by a merge
+// collision (both accounts held the same kind). It mirrors the account package's retain
+// reasons, kept local to avoid importing that package's unexported constants.
+const retainReasonMerge = "merge"
+
 // Friendship statuses, highest precedence first, mirroring internal/social.
 const (
 	friendAccepted = "accepted"
@@ -75,6 +80,9 @@ func (m *Merger) Merge(ctx context.Context, primary, secondary uuid.UUID) error
 		if err := mergeAccountFields(ctx, tx, primary, secondary, now); err != nil {
 			return err
 		}
+		if err := dedupeIdentities(ctx, tx, primary, secondary); err != nil {
+			return err
+		}
 		if err := reassignColumn(ctx, tx, table.Identities, table.Identities.AccountID, primary, secondary); err != nil {
 			return fmt.Errorf("accountmerge: identities: %w", err)
 		}
@@ -300,6 +308,77 @@ func reassignColumn(ctx context.Context, tx *sql.Tx, tbl postgres.Table, col pos
 	return err
 }
 
+// dedupeIdentities resolves a same-kind identity collision before the blanket identity
+// reassign: when both accounts already hold an identity of the same kind (e.g. each has a
+// confirmed email — reachable when two email-bearing accounts merge), the primary keeps
+// its own and the secondary's is journaled to retained_identities (reason=merge) and
+// removed. Without this the blanket reassign would leave the survivor with two identities
+// of one kind (there is no per-account-kind unique on identities), which the profile and
+// the retention dossier both treat as singular. Non-colliding identities are untouched and
+// move with the blanket reassign.
+func dedupeIdentities(ctx context.Context, tx *sql.Tx, primary, secondary uuid.UUID) error {
+	var prows []model.Identities
+	if err := postgres.SELECT(table.Identities.Kind).
+		FROM(table.Identities).
+		WHERE(table.Identities.AccountID.EQ(postgres.UUID(primary))).
+		QueryContext(ctx, tx, &prows); err != nil && !errors.Is(err, qrm.ErrNoRows) {
+		return fmt.Errorf("accountmerge: primary identity kinds: %w", err)
+	}
+	occupied := make(map[string]struct{}, len(prows))
+	for _, r := range prows {
+		occupied[r.Kind] = struct{}{}
+	}
+	if len(occupied) == 0 {
+		return nil
+	}
+	var srows []model.Identities
+	if err := postgres.SELECT(
+		table.Identities.Kind, table.Identities.ExternalID,
+		table.Identities.Confirmed, table.Identities.CreatedAt,
+	).FROM(table.Identities).
+		WHERE(table.Identities.AccountID.EQ(postgres.UUID(secondary))).
+		QueryContext(ctx, tx, &srows); err != nil && !errors.Is(err, qrm.ErrNoRows) {
+		return fmt.Errorf("accountmerge: secondary identities: %w", err)
+	}
+	for _, s := range srows {
+		if _, dup := occupied[s.Kind]; !dup {
+			continue
+		}
+		if err := retainMergedIdentity(ctx, tx, secondary, s); err != nil {
+			return err
+		}
+		del := table.Identities.DELETE().WHERE(
+			table.Identities.AccountID.EQ(postgres.UUID(secondary)).
+				AND(table.Identities.Kind.EQ(postgres.String(s.Kind))).
+				AND(table.Identities.ExternalID.EQ(postgres.String(s.ExternalID))),
+		)
+		if _, err := del.ExecContext(ctx, tx); err != nil {
+			return fmt.Errorf("accountmerge: drop colliding %s identity: %w", s.Kind, err)
+		}
+	}
+	return nil
+}
+
+// retainMergedIdentity appends a retained_identities row for a secondary identity dropped
+// by a merge collision (reason=merge), preserving it in the legal dossier. It mirrors
+// account.retainIdentityTx, which is unexported; detached_at falls to the column default.
+func retainMergedIdentity(ctx context.Context, tx *sql.Tx, accountID uuid.UUID, id model.Identities) error {
+	rid, err := uuid.NewV7()
+	if err != nil {
+		return fmt.Errorf("accountmerge: new retained id: %w", err)
+	}
+	ins := table.RetainedIdentities.INSERT(
+		table.RetainedIdentities.RetainedID, table.RetainedIdentities.AccountID,
+		table.RetainedIdentities.Kind, table.RetainedIdentities.ExternalID,
+		table.RetainedIdentities.Confirmed, table.RetainedIdentities.LinkedAt,
+		table.RetainedIdentities.Reason,
+	).VALUES(rid, accountID, id.Kind, id.ExternalID, id.Confirmed, id.CreatedAt, retainReasonMerge)
+	if _, err := ins.ExecContext(ctx, tx); err != nil {
+		return fmt.Errorf("accountmerge: retain merged %s identity: %w", id.Kind, err)
+	}
+	return nil
+}
+
 // friendRank ranks a friendship status for dedupe precedence (higher wins).
 func friendRank(status string) int {
 	switch status {

backend/internal/adminalert/notify.go

@@ -0,0 +1,116 @@
+// Package adminalert emails the operator when new player feedback or word complaints
+// arrive, coalescing a burst into a single digest per interval so a flood is one email,
+// not N. It is inert unless an admin sender and recipient are configured. The sender is
+// distinct from the user-facing confirm-code From, and the recipient may be several
+// comma-separated addresses (the mailer splits them).
+package adminalert
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	"go.uber.org/zap"
+
+	"scrabble/backend/internal/account"
+)
+
+// FeedbackCounter counts feedback created since a time (satisfied by feedback.Service).
+type FeedbackCounter interface {
+	CountSince(ctx context.Context, since time.Time) (int, error)
+}
+
+// ComplaintCounter counts word complaints filed since a time (satisfied by game.Service).
+type ComplaintCounter interface {
+	CountComplaintsSince(ctx context.Context, since time.Time) (int, error)
+}
+
+// Notifier polls for new feedback and complaints and emails the operator a digest.
+type Notifier struct {
+	mailer     account.Mailer
+	feedback   FeedbackCounter
+	complaints ComplaintCounter
+	from       string
+	to         string
+	consoleURL string
+	clock      func() time.Time
+	log        *zap.Logger
+	last       time.Time
+}
+
+// New constructs a Notifier. from and to are the alert sender and recipient(s); consoleURL,
+// when non-empty, is the admin-console link included in the email. log may be nil. The
+// watermark starts at "now", so only items arriving after start-up are reported.
+func New(mailer account.Mailer, fb FeedbackCounter, cp ComplaintCounter, from, to, consoleURL string, log *zap.Logger) *Notifier {
+	if log == nil {
+		log = zap.NewNop()
+	}
+	return &Notifier{
+		mailer: mailer, feedback: fb, complaints: cp, from: from, to: to, consoleURL: consoleURL,
+		clock: func() time.Time { return time.Now().UTC() }, log: log, last: time.Now().UTC(),
+	}
+}
+
+// Run polls on each tick until ctx is cancelled.
+func (n *Notifier) Run(ctx context.Context, interval time.Duration) {
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			n.tick(ctx)
+		}
+	}
+}
+
+// tick counts what arrived since the last watermark and, if anything did, emails one
+// digest. The watermark only advances after a successful send (or a quiet tick), so a
+// transient send failure is retried on the next tick — the counts simply grow.
+func (n *Notifier) tick(ctx context.Context) {
+	now := n.clock()
+	fb, err := n.feedback.CountSince(ctx, n.last)
+	if err != nil {
+		n.log.Warn("admin alert: count feedback failed", zap.Error(err))
+		return
+	}
+	cp, err := n.complaints.CountComplaintsSince(ctx, n.last)
+	if err != nil {
+		n.log.Warn("admin alert: count complaints failed", zap.Error(err))
+		return
+	}
+	if fb == 0 && cp == 0 {
+		n.last = now
+		return
+	}
+	if err := n.mailer.Send(ctx, n.digest(fb, cp)); err != nil {
+		n.log.Warn("admin alert: send failed", zap.Error(err))
+		return
+	}
+	n.log.Info("admin alert sent", zap.Int("feedback", fb), zap.Int("complaints", cp))
+	n.last = now
+}
+
+// digest builds the operator alert email for fb new feedback and cp new complaints.
+func (n *Notifier) digest(fb, cp int) account.Message {
+	var parts []string
+	if fb > 0 {
+		parts = append(parts, fmt.Sprintf("%d new feedback message(s)", fb))
+	}
+	if cp > 0 {
+		parts = append(parts, fmt.Sprintf("%d new word complaint(s)", cp))
+	}
+	summary := strings.Join(parts, ", ")
+	text := summary + "."
+	if n.consoleURL != "" {
+		text += "\n\nOpen the admin console: " + n.consoleURL
+	}
+	return account.Message{
+		From:    n.from,
+		To:      n.to,
+		Subject: "Erudit — " + summary,
+		Text:    text,
+	}
+}

backend/internal/adminalert/notify_test.go

@@ -0,0 +1,55 @@
+package adminalert
+
+import (
+	"context"
+	"strings"
+	"testing"
+	"time"
+
+	"scrabble/backend/internal/account"
+)
+
+// The fakes ignore the watermark and return a fixed count, which is all the digest logic
+// needs.
+type fbCounter struct{ n int }
+
+func (f fbCounter) CountSince(context.Context, time.Time) (int, error) { return f.n, nil }
+
+type cpCounter struct{ n int }
+
+func (c cpCounter) CountComplaintsSince(context.Context, time.Time) (int, error) { return c.n, nil }
+
+type recordingMailer struct{ sent []account.Message }
+
+func (m *recordingMailer) Send(_ context.Context, msg account.Message) error {
+	m.sent = append(m.sent, msg)
+	return nil
+}
+
+func TestNotifierSkipsWhenNothingNew(t *testing.T) {
+	mailer := &recordingMailer{}
+	n := New(mailer, fbCounter{0}, cpCounter{0}, "alerts@erudit-game.ru", "op@x.ru", "", nil)
+	n.tick(context.Background())
+	if len(mailer.sent) != 0 {
+		t.Fatalf("sent %d emails, want 0 when nothing is new", len(mailer.sent))
+	}
+}
+
+func TestNotifierDigestsNewItems(t *testing.T) {
+	mailer := &recordingMailer{}
+	n := New(mailer, fbCounter{2}, cpCounter{1}, "alerts@erudit-game.ru", "op@x.ru, two@x.ru", "https://erudit-game.ru/_gm", nil)
+	n.tick(context.Background())
+	if len(mailer.sent) != 1 {
+		t.Fatalf("sent %d emails, want 1 digest", len(mailer.sent))
+	}
+	msg := mailer.sent[0]
+	if msg.From != "alerts@erudit-game.ru" || msg.To != "op@x.ru, two@x.ru" {
+		t.Errorf("digest addressing = From %q To %q", msg.From, msg.To)
+	}
+	if !strings.Contains(msg.Subject, "2 new feedback") || !strings.Contains(msg.Subject, "1 new word complaint") {
+		t.Errorf("digest subject = %q, want the feedback + complaint counts", msg.Subject)
+	}
+	if !strings.Contains(msg.Text, "/_gm") {
+		t.Errorf("digest body = %q, want the console link", msg.Text)
+	}
+}

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

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

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

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

backend/internal/adminconsole/views.go

@@ -60,8 +60,10 @@ type UsersView struct {
 	// be emitted verbatim — interpolated as a plain string it would have its "=" and "&"
 	// percent-encoded again by the contextual escaper.
 	Robots         bool
+	Deleted        bool
 	NameMask       string
 	ExternalIDMask string
+	EmailExact     string
 	FilterQuery    template.URL
 }
 
@@ -74,6 +76,7 @@ type UserRow struct {
 	Kind            string
 	Language        string
 	Guest           bool
+	Deleted         bool
 	FlaggedHighRate bool
 	CreatedAt       string
 	HasMoveStats    bool
@@ -150,6 +153,15 @@ type UserDetailView struct {
 	// MergedInto is the primary account id when this account has been retired by a
 	// merge, or empty for a live account.
 	MergedInto string
+	// The account-deletion dossier. Deleted marks a tombstoned account; DeletedAt and
+	// DeletedName are its deletion time and retained real name; LastLoginAt/IP are the
+	// last cold-load stamp (shown for any account); Retained is the credential journal.
+	Deleted     bool
+	DeletedAt   string
+	DeletedName string
+	LastLoginAt string
+	LastLoginIP string
+	Retained    []RetainedRow
 	// FlaggedHighRateAt is the pre-formatted soft high-rate marker timestamp,
 	// empty for an unflagged account; the card shows it with the Clear action.
 	FlaggedHighRateAt string
@@ -161,6 +173,8 @@ type UserDetailView struct {
 	HasStats     bool
 	Stats        StatsRow
 	Identities   []IdentityRow
+	// HasEmail gates the "Erase email" action; set when the account carries an email identity.
+	HasEmail bool
 	Games    []GameRow
 	// TelegramID and VKID are the account's platform external ids (empty when absent).
 	// TelegramID gates the "Send Telegram message" operator action; VKID surfaces the VK
@@ -234,6 +248,17 @@ type IdentityRow struct {
 	CreatedAt  string
 }
 
+// RetainedRow is one credential in the account-deletion retention journal (the legal
+// dossier of detached credentials): what was detached, when, and why.
+type RetainedRow struct {
+	Kind       string
+	ExternalID string
+	Reason     string
+	Confirmed  bool
+	LinkedAt   string
+	DetachedAt string
+}
+
 // GameRow is one game row in a list.
 type GameRow struct {
 	ID        string

backend/internal/config/config.go

@@ -149,6 +149,8 @@ func Load() (Config, error) {
 		Password:  os.Getenv("BACKEND_SMTP_PASSWORD"),
 		From:      envOr("BACKEND_SMTP_FROM", "no-reply@localhost"),
 		TLS:       os.Getenv("BACKEND_SMTP_TLS"),
+		AdminFrom: os.Getenv("BACKEND_SMTP_ADMIN_FROM"),
+		AdminTo:   os.Getenv("BACKEND_ADMIN_EMAIL"),
 	}
 
 	c := Config{

backend/internal/feedback/service.go

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

backend/internal/feedback/store.go

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

backend/internal/game/service.go

@@ -1008,6 +1008,12 @@ func (svc *Service) CountComplaints(ctx context.Context, status string) (int, er
 	return svc.store.CountComplaints(ctx, status)
 }
 
+// CountComplaintsSince counts word complaints filed after since, for the operator alert
+// worker.
+func (svc *Service) CountComplaintsSince(ctx context.Context, since time.Time) (int, error) {
+	return svc.store.CountComplaintsSince(ctx, since)
+}
+
 // ResolveComplaint closes a complaint with an operator disposition (reject /
 // accept_add / accept_remove) and an optional note. An accepted complaint then
 // appears in DictionaryChanges until a rebuilt dictionary is loaded and the

backend/internal/game/store.go

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

backend/internal/inttest/adminemail_test.go

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

backend/internal/inttest/delete_test.go

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

backend/internal/inttest/link_change_test.go

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

backend/internal/inttest/merge_test.go

@@ -251,6 +251,44 @@ func TestAccountMergeFinishedSharedGameKept(t *testing.T) {
 	}
 }
 
+// TestAccountMergeDedupesEmail keeps the primary's email when both accounts have one and
+// journals the secondary's to the dossier (reason=merge), so the survivor never ends up
+// with two email identities.
+func TestAccountMergeDedupesEmail(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	merger := accountmerge.NewMerger(testDB)
+
+	primary := provisionAccount(t)
+	secondary := provisionAccount(t)
+	primaryEmail := "keep-" + uuid.NewString() + "@example.com"
+	secondaryEmail := "absorb-" + uuid.NewString() + "@example.com"
+	bindEmailIdentity(t, primary, primaryEmail)
+	bindEmailIdentity(t, secondary, secondaryEmail)
+
+	if err := merger.Merge(ctx, primary, secondary); err != nil {
+		t.Fatalf("merge: %v", err)
+	}
+
+	// The primary keeps its own email; the secondary's is gone from the live identities.
+	if owner, ok, _ := store.AccountIDByIdentity(ctx, account.KindEmail, primaryEmail); !ok || owner != primary {
+		t.Errorf("primary email owner = %s ok=%v, want primary %s", owner, ok, primary)
+	}
+	if _, ok, _ := store.AccountIDByIdentity(ctx, account.KindEmail, secondaryEmail); ok {
+		t.Error("the secondary's email must be removed (no duplicate email on the survivor)")
+	}
+	// The absorbed email stays in the legal dossier, tagged reason=merge.
+	var reason string
+	if err := testDB.QueryRowContext(ctx,
+		`SELECT reason FROM backend.retained_identities WHERE account_id=$1 AND kind='email' AND external_id=$2`,
+		secondary, secondaryEmail).Scan(&reason); err != nil {
+		t.Fatalf("retained email row: %v", err)
+	}
+	if reason != "merge" {
+		t.Errorf("retained reason = %q, want merge", reason)
+	}
+}
+
 // TestAccountLinkFreeEmail binds a free email and promotes a guest to durable.
 func TestAccountLinkFreeEmail(t *testing.T) {
 	ctx := context.Background()
@@ -355,3 +393,64 @@ func TestAccountLinkGuestInversion(t *testing.T) {
 		t.Errorf("email owner = %s, want durable", owner)
 	}
 }
+
+// TestAccountLinkFreeVK binds a free VK identity (gateway-validated, no code) and
+// promotes a guest to durable — the ConfirmVK counterpart of the free-email case.
+func TestAccountLinkFreeVK(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	links := newLinkService(&capturingMailer{})
+
+	guest := provisionGuest(t)
+	vkID := "vk-" + uuid.NewString()
+	res, err := links.ConfirmVK(ctx, guest, vkID)
+	if err != nil {
+		t.Fatalf("confirm vk: %v", err)
+	}
+	if !res.Linked || res.MergeRequired {
+		t.Fatalf("confirm = %+v, want linked", res)
+	}
+	if acc, _ := store.GetByID(ctx, guest); acc.IsGuest {
+		t.Error("guest flag should clear once VK is linked")
+	}
+	if owner, ok, _ := store.AccountIDByIdentity(ctx, account.KindVK, vkID); !ok || owner != guest {
+		t.Errorf("vk owner = %s, want the promoted guest %s", owner, guest)
+	}
+}
+
+// TestAccountLinkVKMergeIntoCaller merges the account owning a VK identity into the
+// current durable account: ConfirmVK previews the merge, MergeVK folds it, the caller
+// stays primary and keeps its session, and the VK identity repoints to the caller.
+func TestAccountLinkVKMergeIntoCaller(t *testing.T) {
+	ctx := context.Background()
+	store := account.NewStore(testDB)
+	links := newLinkService(&capturingMailer{})
+
+	caller := provisionAccount(t)
+	other := provisionAccount(t)
+	vkID := "vk-" + uuid.NewString()
+	if err := store.AttachIdentity(ctx, other, account.KindVK, vkID, true); err != nil {
+		t.Fatalf("seed vk on other: %v", err)
+	}
+
+	confirm, err := links.ConfirmVK(ctx, caller, vkID)
+	if err != nil {
+		t.Fatalf("confirm vk: %v", err)
+	}
+	if !confirm.MergeRequired || confirm.SecondaryID != other {
+		t.Fatalf("confirm = %+v, want merge_required to other %s", confirm, other)
+	}
+	merge, err := links.MergeVK(ctx, caller, vkID)
+	if err != nil {
+		t.Fatalf("merge vk: %v", err)
+	}
+	if merge.PrimaryID != caller || merge.SwitchedToken != "" {
+		t.Fatalf("merge = %+v, want primary caller and no session switch", merge)
+	}
+	if mergedInto(t, other) != caller {
+		t.Error("other should be tombstoned into caller")
+	}
+	if owner, _, _ := store.AccountIDByIdentity(ctx, account.KindVK, vkID); owner != caller {
+		t.Errorf("vk owner = %s, want caller after merge", owner)
+	}
+}

backend/internal/inttest/retention_test.go

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

backend/internal/link/service.go

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

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

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

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

@@ -0,0 +1,24 @@
+//
+// 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 RetainedIdentities struct {
+	RetainedID uuid.UUID `sql:"primary_key"`
+	AccountID  uuid.UUID
+	Kind       string
+	ExternalID string
+	Confirmed  bool
+	LinkedAt   time.Time
+	DetachedAt time.Time
+	Reason     string
+}

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

@@ -35,6 +35,10 @@ type accountsTable struct {
 	MergedAt               postgres.ColumnTimestampz
 	FlaggedHighRateAt      postgres.ColumnTimestampz
 	VariantPreferences     postgres.ColumnStringArray
+	LastLoginAt            postgres.ColumnTimestampz
+	LastLoginIP            postgres.ColumnString
+	DeletedAt              postgres.ColumnTimestampz
+	DeletedDisplayName     postgres.ColumnString
 
 	AllColumns     postgres.ColumnList
 	MutableColumns postgres.ColumnList
@@ -94,8 +98,12 @@ func newAccountsTableImpl(schemaName, tableName, alias string) accountsTable {
 		MergedAtColumn               = postgres.TimestampzColumn("merged_at")
 		FlaggedHighRateAtColumn      = postgres.TimestampzColumn("flagged_high_rate_at")
 		VariantPreferencesColumn     = postgres.StringArrayColumn("variant_preferences")
-		allColumns                   = postgres.ColumnList{AccountIDColumn, DisplayNameColumn, PreferredLanguageColumn, TimeZoneColumn, BlockChatColumn, BlockFriendRequestsColumn, CreatedAtColumn, UpdatedAtColumn, AwayStartColumn, AwayEndColumn, HintBalanceColumn, IsGuestColumn, NotificationsInAppOnlyColumn, PaidAccountColumn, MergedIntoColumn, MergedAtColumn, FlaggedHighRateAtColumn, VariantPreferencesColumn}
-		mutableColumns               = postgres.ColumnList{DisplayNameColumn, PreferredLanguageColumn, TimeZoneColumn, BlockChatColumn, BlockFriendRequestsColumn, CreatedAtColumn, UpdatedAtColumn, AwayStartColumn, AwayEndColumn, HintBalanceColumn, IsGuestColumn, NotificationsInAppOnlyColumn, PaidAccountColumn, MergedIntoColumn, MergedAtColumn, FlaggedHighRateAtColumn, VariantPreferencesColumn}
+		LastLoginAtColumn            = postgres.TimestampzColumn("last_login_at")
+		LastLoginIPColumn            = postgres.StringColumn("last_login_ip")
+		DeletedAtColumn              = postgres.TimestampzColumn("deleted_at")
+		DeletedDisplayNameColumn     = postgres.StringColumn("deleted_display_name")
+		allColumns                   = postgres.ColumnList{AccountIDColumn, DisplayNameColumn, PreferredLanguageColumn, TimeZoneColumn, BlockChatColumn, BlockFriendRequestsColumn, CreatedAtColumn, UpdatedAtColumn, AwayStartColumn, AwayEndColumn, HintBalanceColumn, IsGuestColumn, NotificationsInAppOnlyColumn, PaidAccountColumn, MergedIntoColumn, MergedAtColumn, FlaggedHighRateAtColumn, VariantPreferencesColumn, LastLoginAtColumn, LastLoginIPColumn, DeletedAtColumn, DeletedDisplayNameColumn}
+		mutableColumns               = postgres.ColumnList{DisplayNameColumn, PreferredLanguageColumn, TimeZoneColumn, BlockChatColumn, BlockFriendRequestsColumn, CreatedAtColumn, UpdatedAtColumn, AwayStartColumn, AwayEndColumn, HintBalanceColumn, IsGuestColumn, NotificationsInAppOnlyColumn, PaidAccountColumn, MergedIntoColumn, MergedAtColumn, FlaggedHighRateAtColumn, VariantPreferencesColumn, LastLoginAtColumn, LastLoginIPColumn, DeletedAtColumn, DeletedDisplayNameColumn}
 		defaultColumns               = postgres.ColumnList{DisplayNameColumn, PreferredLanguageColumn, TimeZoneColumn, BlockChatColumn, BlockFriendRequestsColumn, CreatedAtColumn, UpdatedAtColumn, AwayStartColumn, AwayEndColumn, HintBalanceColumn, IsGuestColumn, NotificationsInAppOnlyColumn, PaidAccountColumn, VariantPreferencesColumn}
 	)
 
@@ -121,6 +129,10 @@ func newAccountsTableImpl(schemaName, tableName, alias string) accountsTable {
 		MergedAt:               MergedAtColumn,
 		FlaggedHighRateAt:      FlaggedHighRateAtColumn,
 		VariantPreferences:     VariantPreferencesColumn,
+		LastLoginAt:            LastLoginAtColumn,
+		LastLoginIP:            LastLoginIPColumn,
+		DeletedAt:              DeletedAtColumn,
+		DeletedDisplayName:     DeletedDisplayNameColumn,
 
 		AllColumns:     allColumns,
 		MutableColumns: mutableColumns,

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

@@ -0,0 +1,99 @@
+//
+// 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 RetainedIdentities = newRetainedIdentitiesTable("backend", "retained_identities", "")
+
+type retainedIdentitiesTable struct {
+	postgres.Table
+
+	// Columns
+	RetainedID postgres.ColumnString
+	AccountID  postgres.ColumnString
+	Kind       postgres.ColumnString
+	ExternalID postgres.ColumnString
+	Confirmed  postgres.ColumnBool
+	LinkedAt   postgres.ColumnTimestampz
+	DetachedAt postgres.ColumnTimestampz
+	Reason     postgres.ColumnString
+
+	AllColumns     postgres.ColumnList
+	MutableColumns postgres.ColumnList
+	DefaultColumns postgres.ColumnList
+}
+
+type RetainedIdentitiesTable struct {
+	retainedIdentitiesTable
+
+	EXCLUDED retainedIdentitiesTable
+}
+
+// AS creates new RetainedIdentitiesTable with assigned alias
+func (a RetainedIdentitiesTable) AS(alias string) *RetainedIdentitiesTable {
+	return newRetainedIdentitiesTable(a.SchemaName(), a.TableName(), alias)
+}
+
+// Schema creates new RetainedIdentitiesTable with assigned schema name
+func (a RetainedIdentitiesTable) FromSchema(schemaName string) *RetainedIdentitiesTable {
+	return newRetainedIdentitiesTable(schemaName, a.TableName(), a.Alias())
+}
+
+// WithPrefix creates new RetainedIdentitiesTable with assigned table prefix
+func (a RetainedIdentitiesTable) WithPrefix(prefix string) *RetainedIdentitiesTable {
+	return newRetainedIdentitiesTable(a.SchemaName(), prefix+a.TableName(), a.TableName())
+}
+
+// WithSuffix creates new RetainedIdentitiesTable with assigned table suffix
+func (a RetainedIdentitiesTable) WithSuffix(suffix string) *RetainedIdentitiesTable {
+	return newRetainedIdentitiesTable(a.SchemaName(), a.TableName()+suffix, a.TableName())
+}
+
+func newRetainedIdentitiesTable(schemaName, tableName, alias string) *RetainedIdentitiesTable {
+	return &RetainedIdentitiesTable{
+		retainedIdentitiesTable: newRetainedIdentitiesTableImpl(schemaName, tableName, alias),
+		EXCLUDED:                newRetainedIdentitiesTableImpl("", "excluded", ""),
+	}
+}
+
+func newRetainedIdentitiesTableImpl(schemaName, tableName, alias string) retainedIdentitiesTable {
+	var (
+		RetainedIDColumn = postgres.StringColumn("retained_id")
+		AccountIDColumn  = postgres.StringColumn("account_id")
+		KindColumn       = postgres.StringColumn("kind")
+		ExternalIDColumn = postgres.StringColumn("external_id")
+		ConfirmedColumn  = postgres.BoolColumn("confirmed")
+		LinkedAtColumn   = postgres.TimestampzColumn("linked_at")
+		DetachedAtColumn = postgres.TimestampzColumn("detached_at")
+		ReasonColumn     = postgres.StringColumn("reason")
+		allColumns       = postgres.ColumnList{RetainedIDColumn, AccountIDColumn, KindColumn, ExternalIDColumn, ConfirmedColumn, LinkedAtColumn, DetachedAtColumn, ReasonColumn}
+		mutableColumns   = postgres.ColumnList{AccountIDColumn, KindColumn, ExternalIDColumn, ConfirmedColumn, LinkedAtColumn, DetachedAtColumn, ReasonColumn}
+		defaultColumns   = postgres.ColumnList{ConfirmedColumn, DetachedAtColumn}
+	)
+
+	return retainedIdentitiesTable{
+		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
+
+		//Columns
+		RetainedID: RetainedIDColumn,
+		AccountID:  AccountIDColumn,
+		Kind:       KindColumn,
+		ExternalID: ExternalIDColumn,
+		Confirmed:  ConfirmedColumn,
+		LinkedAt:   LinkedAtColumn,
+		DetachedAt: DetachedAtColumn,
+		Reason:     ReasonColumn,
+
+		AllColumns:     allColumns,
+		MutableColumns: mutableColumns,
+		DefaultColumns: defaultColumns,
+	}
+}

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

@@ -34,6 +34,7 @@ func UseSchema(schema string) {
 	GameSetupDraws = GameSetupDraws.FromSchema(schema)
 	Games = Games.FromSchema(schema)
 	Identities = Identities.FromSchema(schema)
+	RetainedIdentities = RetainedIdentities.FromSchema(schema)
 	Sessions = Sessions.FromSchema(schema)
 	SuspensionReasons = SuspensionReasons.FromSchema(schema)
 }

backend/internal/postgres/migrations/00007_account_deletion_retention.sql

@@ -0,0 +1,47 @@
+-- Account deletion as legal retention (not erasure). Two additive pieces.
+--
+-- retained_identities is an append-only journal of every credential detached from an
+-- account — on unlink, email change, or account deletion (reason). It preserves the legal
+-- dossier (which email/vk/tg was linked, and when) while the live identities row is
+-- removed, so the (kind, external_id) frees for a new account to reuse. No unique
+-- constraint and no kind CHECK: the same credential may recur across accounts and events,
+-- and the log stays robust to future identity kinds. detached_at drives the retention TTL.
+--
+-- accounts gains: last_login_at / last_login_ip (stamped on a cold app-load, throttled),
+-- deleted_at (the tombstone marker), and deleted_display_name (the real name retained for
+-- the admin dossier after the live display_name is scrubbed to the anonymised label).
+--
+-- Expand-contract: everything is additive (a new table plus nullable columns), so a
+-- backend image rollback stays DB-safe — older code simply ignores them. The accounts
+-- table shape changes, so its generated go-jet model is regenerated.
+
+-- +goose Up
+CREATE TABLE backend.retained_identities (
+    retained_id uuid NOT NULL,
+    account_id uuid NOT NULL,
+    kind text NOT NULL,
+    external_id text NOT NULL,
+    confirmed boolean DEFAULT false NOT NULL,
+    linked_at timestamp with time zone NOT NULL,
+    detached_at timestamp with time zone DEFAULT now() NOT NULL,
+    reason text NOT NULL,
+    CONSTRAINT retained_identities_pkey PRIMARY KEY (retained_id),
+    CONSTRAINT retained_identities_reason_chk
+        CHECK ((reason = ANY (ARRAY['unlink'::text, 'change'::text, 'delete'::text])))
+);
+CREATE INDEX retained_identities_account_id_idx ON backend.retained_identities (account_id);
+CREATE INDEX retained_identities_detached_at_idx ON backend.retained_identities (detached_at);
+
+ALTER TABLE backend.accounts
+    ADD COLUMN last_login_at timestamp with time zone,
+    ADD COLUMN last_login_ip text,
+    ADD COLUMN deleted_at timestamp with time zone,
+    ADD COLUMN deleted_display_name text;
+
+-- +goose Down
+ALTER TABLE backend.accounts
+    DROP COLUMN last_login_at,
+    DROP COLUMN last_login_ip,
+    DROP COLUMN deleted_at,
+    DROP COLUMN deleted_display_name;
+DROP TABLE backend.retained_identities;

backend/internal/postgres/migrations/00008_retained_identities_merge_reason.sql

@@ -0,0 +1,22 @@
+-- Admit the 'merge' reason into retained_identities. An account merge folds a secondary
+-- account into a primary; when both hold an identity of the same kind (e.g. each has a
+-- confirmed email), the survivor keeps its own and the secondary's is journaled to the
+-- legal dossier and removed — so the survivor never ends up with two identities of one
+-- kind, and the absorbed credential is still retained. That journal row carries reason
+-- 'merge', alongside the existing unlink / change / delete.
+--
+-- Expand-contract: the Up only WIDENS the allowed reason set, so an older backend image
+-- (which writes only unlink/change/delete) still satisfies the constraint — a rollback
+-- stays DB-safe. The Down narrows it again and would reject pre-existing 'merge' rows, so
+-- it is a dev-only convenience, not a production rollback path (image rollback runs old
+-- code against this schema, not the Down migration).
+
+-- +goose Up
+ALTER TABLE backend.retained_identities DROP CONSTRAINT retained_identities_reason_chk;
+ALTER TABLE backend.retained_identities ADD CONSTRAINT retained_identities_reason_chk
+    CHECK ((reason = ANY (ARRAY['unlink'::text, 'change'::text, 'delete'::text, 'merge'::text])));
+
+-- +goose Down
+ALTER TABLE backend.retained_identities DROP CONSTRAINT retained_identities_reason_chk;
+ALTER TABLE backend.retained_identities ADD CONSTRAINT retained_identities_reason_chk
+    CHECK ((reason = ANY (ARRAY['unlink'::text, 'change'::text, 'delete'::text])));

backend/internal/server/banner.go

@@ -45,9 +45,34 @@ type bannerTimingsDTO struct {
 func (s *Server) profileResponse(ctx context.Context, acc account.Account) profileResponse {
 	r := profileResponseFor(acc)
 	r.Banner = s.bannerFor(ctx, acc)
+	s.fillLinkedIdentities(ctx, &r, acc.ID)
 	return r
 }
 
+// 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
+// warning so the profile response still succeeds.
+func (s *Server) fillLinkedIdentities(ctx context.Context, r *profileResponse, accountID uuid.UUID) {
+	ids, err := s.accounts.Identities(ctx, accountID)
+	if err != nil {
+		s.log.Warn("profile: identities read failed", zap.String("account", accountID.String()), zap.Error(err))
+		return
+	}
+	for _, id := range ids {
+		switch id.Kind {
+		case account.KindEmail:
+			if id.Confirmed {
+				r.Email = id.ExternalID
+			}
+		case account.KindTelegram:
+			r.TelegramLinked = true
+		case account.KindVK:
+			r.VkLinked = true
+		}
+	}
+}
+
 // bannerFor builds the advertising-banner block for the account's profile, or
 // nil when the ads service is not configured or the viewer is not eligible to
 // see a banner. The message language follows the account's bot (service)

backend/internal/server/dto.go

@@ -56,6 +56,13 @@ type profileResponse struct {
 	// see the banner (a free account with an empty hint wallet and without the
 	// no_banner role), absent otherwise. See banner.go.
 	Banner *bannerDTO `json:"banner,omitempty"`
+	// Email is the account's confirmed email address ("" when none); TelegramLinked and
+	// VkLinked report whether a platform identity is attached. They drive the profile's
+	// link / unlink / change-email controls, and are filled outside the pure projection
+	// (they read the account's identities). See Server.profileResponse.
+	Email          string `json:"email"`
+	TelegramLinked bool   `json:"telegram_linked"`
+	VkLinked       bool   `json:"vk_linked"`
 }
 
 // tileDTO is one placed (or to-place) tile.

backend/internal/server/handlers.go

@@ -74,6 +74,18 @@ func (s *Server) registerRoutes() {
 		u.POST("/link/email/merge", s.handleLinkEmailMerge)
 		u.POST("/link/telegram", s.handleLinkTelegram)
 		u.POST("/link/telegram/merge", s.handleLinkTelegramMerge)
+		u.POST("/link/vk", s.handleLinkVK)
+		u.POST("/link/vk/merge", s.handleLinkVKMerge)
+		u.POST("/link/unlink", s.handleUnlink)
+		// Change the account's confirmed email: mail a code to the new address, then
+		// atomically switch on confirm (a new address owned by another account is
+		// refused without disclosure, never merged).
+		u.POST("/link/email/change/request", s.handleChangeEmailRequest)
+		u.POST("/link/email/change/confirm", s.handleChangeEmailConfirm)
+		// Account deletion (legal retention, not erasure): step-up via a mailed code
+		// (email accounts) or a typed phrase (platform-only), then tombstone + free creds.
+		u.POST("/delete/request", s.handleRequestDelete)
+		u.POST("/delete/confirm", s.handleConfirmDelete)
 	}
 	if s.games != nil {
 		u.GET("/games", s.handleListGames)
@@ -231,6 +243,8 @@ func statusForError(err error) (int, string) {
 		return http.StatusUnprocessableEntity, "illegal_play"
 	case errors.Is(err, account.ErrEmailTaken), errors.Is(err, account.ErrIdentityTaken):
 		return http.StatusConflict, "email_taken"
+	case errors.Is(err, account.ErrLastIdentity):
+		return http.StatusConflict, "last_identity"
 	case errors.Is(err, accountmerge.ErrActiveGameConflict):
 		return http.StatusConflict, "merge_active_game_conflict"
 	case errors.Is(err, account.ErrInvalidEmail):

backend/internal/server/handlers_admin_console.go

@@ -61,6 +61,8 @@ func (s *Server) registerConsole(router *gin.Engine) {
 	gm.POST("/users/:id/unblock", s.consoleUnblockUser)
 	gm.POST("/users/:id/grant-role", s.consoleGrantRole)
 	gm.POST("/users/:id/revoke-role", s.consoleRevokeRole)
+	gm.POST("/users/:id/remove-email", s.consoleRemoveEmail)
+	gm.POST("/users/:id/delete", s.consoleDeleteUser)
 	gm.GET("/reasons", s.consoleReasons)
 	gm.POST("/reasons", s.consoleCreateReason)
 	gm.POST("/reasons/:id/update", s.consoleUpdateReason)
@@ -132,8 +134,10 @@ func (s *Server) consoleUsers(c *gin.Context) {
 	page := consolePage(c)
 	filter := account.UserFilter{
 		Robots:         c.Query("kind") == "robots",
+		Deleted:        c.Query("kind") == "deleted",
 		NameMask:       c.Query("name"),
 		ExternalIDMask: c.Query("ext"),
+		EmailExact:     c.Query("email"),
 	}
 	total, _ := s.accounts.CountUsers(ctx, filter)
 	items, err := s.accounts.ListUsers(ctx, filter, adminPageSize, (page-1)*adminPageSize)
@@ -145,28 +149,38 @@ func (s *Server) consoleUsers(c *gin.Context) {
 	if filter.Robots {
 		q.Set("kind", "robots")
 	}
+	if filter.Deleted {
+		q.Set("kind", "deleted")
+	}
 	if strings.TrimSpace(filter.NameMask) != "" {
 		q.Set("name", filter.NameMask)
 	}
 	if strings.TrimSpace(filter.ExternalIDMask) != "" {
 		q.Set("ext", filter.ExternalIDMask)
 	}
+	if strings.TrimSpace(filter.EmailExact) != "" {
+		q.Set("email", filter.EmailExact)
+	}
 	view := adminconsole.UsersView{
 		Pager:  adminconsole.NewPager(page, adminPageSize, total),
-		Robots: filter.Robots, NameMask: filter.NameMask, ExternalIDMask: filter.ExternalIDMask,
+		Robots: filter.Robots, Deleted: filter.Deleted, NameMask: filter.NameMask, ExternalIDMask: filter.ExternalIDMask,
+		EmailExact:  filter.EmailExact,
 		FilterQuery: template.URL(q.Encode()),
 	}
 	ids := make([]uuid.UUID, 0, len(items))
 	for _, it := range items {
 		kind := "registered"
-		if it.IsRobot {
+		switch {
+		case it.IsRobot:
 			kind = "robot"
-		} else if it.IsGuest {
+		case it.IsDeleted:
+			kind = "deleted"
+		case it.IsGuest:
 			kind = "guest"
 		}
 		view.Items = append(view.Items, adminconsole.UserRow{
 			ID: it.ID.String(), DisplayName: it.DisplayName, Kind: kind,
-			Language: it.PreferredLanguage, Guest: it.IsGuest,
+			Language: it.PreferredLanguage, Guest: it.IsGuest, Deleted: it.IsDeleted,
 			FlaggedHighRate: !it.FlaggedHighRateAt.IsZero(), CreatedAt: fmtTime(it.CreatedAt),
 		})
 		ids = append(ids, it.ID)
@@ -356,9 +370,31 @@ func (s *Server) consoleUserDetail(c *gin.Context) {
 	}
 	if ids, err := s.accounts.Identities(ctx, id); err == nil {
 		for _, idn := range ids {
+			if idn.Kind == account.KindEmail {
+				view.HasEmail = true
+			}
 			view.Identities = append(view.Identities, adminconsole.IdentityRow{Kind: idn.Kind, ExternalID: idn.ExternalID, Confirmed: idn.Confirmed, CreatedAt: fmtTime(idn.CreatedAt)})
 		}
 	}
+	if info, err := s.accounts.DeletionInfo(ctx, id); err == nil {
+		if info.LastLoginAt != nil {
+			view.LastLoginAt = fmtTime(*info.LastLoginAt)
+		}
+		view.LastLoginIP = info.LastLoginIP
+		if info.DeletedAt != nil {
+			view.Deleted = true
+			view.DeletedAt = fmtTime(*info.DeletedAt)
+			view.DeletedName = info.DeletedDisplayName
+		}
+	}
+	if rets, err := s.accounts.RetainedIdentities(ctx, id); err == nil {
+		for _, r := range rets {
+			view.Retained = append(view.Retained, adminconsole.RetainedRow{
+				Kind: r.Kind, ExternalID: r.ExternalID, Reason: r.Reason,
+				Confirmed: r.Confirmed, LinkedAt: fmtTime(r.LinkedAt), DetachedAt: fmtTime(r.DetachedAt),
+			})
+		}
+	}
 	if tg, err := s.accounts.IdentityExternalID(ctx, id, account.KindTelegram); err == nil {
 		view.TelegramID = tg
 	}
@@ -951,6 +987,41 @@ func (s *Server) consoleGrantHints(c *gin.Context) {
 	s.renderConsoleMessage(c, "Granted", fmt.Sprintf("added %d hint(s); the wallet is now %d", n, balance), back)
 }
 
+// consoleRemoveEmail deletes the account's bound email identity (and any pending
+// confirmations), freeing the address. It refuses to remove the account's only
+// identity, which would leave it unreachable.
+func (s *Server) consoleRemoveEmail(c *gin.Context) {
+	id, ok := s.consoleUUID(c, "/_gm/users")
+	if !ok {
+		return
+	}
+	back := "/_gm/users/" + id.String()
+	switch err := s.accounts.RemoveEmailIdentity(c.Request.Context(), id); {
+	case errors.Is(err, account.ErrLastIdentity):
+		s.renderConsoleMessage(c, "Can't remove", "the email is this account's only identity — removing it would leave the account unreachable", back)
+	case err != nil:
+		s.consoleError(c, err)
+	default:
+		s.renderConsoleMessage(c, "Removed", "the email identity was erased and the address freed", back)
+	}
+}
+
+// consoleDeleteUser deletes an account from the console — the operator-initiated equivalent
+// of the in-app deletion (legal retention, not erasure): the account is tombstoned, its
+// credentials journalled + freed, its live surfaces anonymised, and its sessions revoked.
+func (s *Server) consoleDeleteUser(c *gin.Context) {
+	id, ok := s.consoleUUID(c, "/_gm/users")
+	if !ok {
+		return
+	}
+	back := "/_gm/users/" + id.String()
+	if err := s.deleteAccount(c.Request.Context(), id); err != nil {
+		s.consoleError(c, err)
+		return
+	}
+	s.renderConsoleMessage(c, "Deleted", "the account was deleted: its credentials were journalled and freed, its data anonymised, and its sessions revoked", back)
+}
+
 // consoleBlockUser manually blocks an account: it records the suspension (permanent or until a
 // parsed deadline, snapshotting the chosen reason's en/ru text) and forfeits the player's active
 // games, removing them from matchmaking. The block takes effect on the player's next request.

backend/internal/server/handlers_delete.go

@@ -0,0 +1,131 @@
+package server
+
+import (
+	"context"
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+	"go.uber.org/zap"
+
+	"scrabble/backend/internal/accountdelete"
+	"scrabble/backend/internal/game"
+)
+
+// Account deletion is legal retention, not erasure (docs/ARCHITECTURE.md §9.1): the account
+// row survives as a tombstone while its credentials are journalled + freed, its live
+// surfaces anonymised, and its own social/ephemeral data dropped. Messages are kept. The
+// step-up is a mailed code for an account with a confirmed email, or a typed phrase for a
+// platform-only account (possession-proof is unattainable there, so the phrase is
+// anti-impulse only).
+
+// deletePhrase is the fixed confirmation phrase a no-email account types to delete.
+// Compared case-insensitively; the client localises only the surrounding instruction.
+const deletePhrase = "DELETE"
+
+// deleteRequestResponse tells the client which step-up the account uses.
+type deleteRequestResponse struct {
+	Method string `json:"method"` // "email" | "phrase"
+}
+
+// handleRequestDelete starts account deletion: it mails a delete code to an account with a
+// confirmed email, or reports the typed-phrase path otherwise.
+func (s *Server) handleRequestDelete(c *gin.Context) {
+	uid, ok := userID(c)
+	if !ok {
+		abortBadRequest(c, "missing identity")
+		return
+	}
+	ctx := c.Request.Context()
+	hasEmail, err := s.emails.HasEmail(ctx, uid)
+	if err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	if !hasEmail {
+		c.JSON(http.StatusOK, deleteRequestResponse{Method: "phrase"})
+		return
+	}
+	if err := s.emails.RequestDeleteCode(ctx, uid); err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, deleteRequestResponse{Method: "email"})
+}
+
+// deleteConfirmBody carries the step-up proof: a mailed code (email account) or the typed
+// phrase (platform-only account).
+type deleteConfirmBody struct {
+	Code   string `json:"code"`
+	Phrase string `json:"phrase"`
+}
+
+// handleConfirmDelete verifies the step-up and deletes the account.
+func (s *Server) handleConfirmDelete(c *gin.Context) {
+	uid, ok := userID(c)
+	if !ok {
+		abortBadRequest(c, "missing identity")
+		return
+	}
+	var req deleteConfirmBody
+	if err := c.ShouldBindJSON(&req); err != nil {
+		abortBadRequest(c, "invalid request body")
+		return
+	}
+	ctx := c.Request.Context()
+	hasEmail, err := s.emails.HasEmail(ctx, uid)
+	if err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	if hasEmail {
+		if err := s.emails.VerifyDeleteCode(ctx, uid, req.Code); err != nil {
+			s.abortErr(c, err)
+			return
+		}
+	} else if !strings.EqualFold(strings.TrimSpace(req.Phrase), deletePhrase) {
+		abortBadRequest(c, "confirmation phrase does not match")
+		return
+	}
+	if err := s.deleteAccount(ctx, uid); err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, okResponse{OK: true})
+}
+
+// deleteAccount runs the deletion orchestration after the step-up passed: it resigns the
+// account's active games (so opponents are not stranded and robot games end cleanly),
+// drops its all-robot games, tombstones + anonymises the account (journalling and freeing
+// its credentials), and revokes its sessions. The tombstone is the point of no return —
+// its failure aborts; the game cleanup and session revocation around it are best-effort.
+func (s *Server) deleteAccount(ctx context.Context, uid uuid.UUID) error {
+	deleter := accountdelete.NewDeleter(s.db)
+	if s.games != nil {
+		if games, err := s.games.ListForAccount(ctx, uid); err == nil {
+			for _, g := range games {
+				if g.Status != game.StatusActive {
+					continue
+				}
+				if _, err := s.games.Resign(ctx, g.ID, uid); err != nil {
+					s.log.Warn("delete: resign game failed", zap.String("game", g.ID.String()), zap.Error(err))
+				}
+			}
+		} else {
+			s.log.Warn("delete: list games failed", zap.Error(err))
+		}
+	}
+	if _, err := deleter.DropAllRobotGames(ctx, uid); err != nil {
+		s.log.Warn("delete: drop all-robot games failed", zap.Error(err))
+	}
+	if err := deleter.AnonymizeAndTombstone(ctx, uid); err != nil {
+		return err
+	}
+	if s.sessions != nil {
+		if err := s.sessions.RevokeAllForAccount(ctx, uid); err != nil {
+			s.log.Warn("delete: revoke sessions failed", zap.Error(err))
+		}
+	}
+	return nil
+}

backend/internal/server/handlers_link.go

@@ -7,6 +7,7 @@ import (
 	"github.com/gin-gonic/gin"
 	"github.com/google/uuid"
 
+	"scrabble/backend/internal/account"
 	"scrabble/backend/internal/link"
 )
 
@@ -33,6 +34,12 @@ type linkTelegramBody struct {
 	ExternalID string `json:"external_id"`
 }
 
+// linkVKBody carries a gateway-validated VK identity (the trusted vk user id the
+// gateway resolved from the VK ID code exchange).
+type linkVKBody struct {
+	ExternalID string `json:"external_id"`
+}
+
 // linkResultResponse is the unified result of a confirm or merge step. Status is
 // "linked" (bound to the caller), "merge_required" (the identity belongs to another
 // account — the secondary_* fields summarise it for the irreversible confirmation),
@@ -66,6 +73,89 @@ func (s *Server) handleLinkEmailRequest(c *gin.Context) {
 	c.JSON(http.StatusOK, okResponse{OK: true})
 }
 
+// unlinkBody carries the provider kind to detach.
+type unlinkBody struct {
+	Kind string `json:"kind"`
+}
+
+// handleUnlink detaches a platform identity (telegram or vk) from the caller's
+// account, refusing to remove the last identity (ErrLastIdentity). Email is never
+// unlinked — it is replaced through the change-email flow — so an email kind is
+// rejected. It returns the refreshed profile so the client updates its controls.
+func (s *Server) handleUnlink(c *gin.Context) {
+	uid, ok := userID(c)
+	if !ok {
+		abortBadRequest(c, "missing identity")
+		return
+	}
+	var req unlinkBody
+	if err := c.ShouldBindJSON(&req); err != nil {
+		abortBadRequest(c, "invalid request body")
+		return
+	}
+	if req.Kind != account.KindTelegram && req.Kind != account.KindVK {
+		abortBadRequest(c, "only telegram or vk can be unlinked")
+		return
+	}
+	ctx := c.Request.Context()
+	if err := s.accounts.RemoveIdentity(ctx, uid, req.Kind); err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	acc, err := s.accounts.GetByID(ctx, uid)
+	if err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	r := s.profileResponse(ctx, acc)
+	c.JSON(http.StatusOK, linkResultResponse{Status: "unlinked", Profile: &r})
+}
+
+// handleChangeEmailRequest mails a confirm-code to a new address for an authenticated
+// email change. Like the link request it never signals "taken" up front — a conflict is
+// only revealed (non-disclosingly) at confirm.
+func (s *Server) handleChangeEmailRequest(c *gin.Context) {
+	uid, ok := userID(c)
+	if !ok {
+		abortBadRequest(c, "missing identity")
+		return
+	}
+	var req linkEmailRequestBody
+	if err := c.ShouldBindJSON(&req); err != nil {
+		abortBadRequest(c, "invalid request body")
+		return
+	}
+	if err := s.emails.RequestChangeCode(c.Request.Context(), uid, req.Email); err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, okResponse{OK: true})
+}
+
+// handleChangeEmailConfirm verifies the code and atomically switches the account to the
+// new address, returning the refreshed profile. A new address confirmed by another
+// account is refused (ErrEmailTaken → the non-disclosing message), never merged.
+func (s *Server) handleChangeEmailConfirm(c *gin.Context) {
+	uid, ok := userID(c)
+	if !ok {
+		abortBadRequest(c, "missing identity")
+		return
+	}
+	var req linkEmailConfirmBody
+	if err := c.ShouldBindJSON(&req); err != nil {
+		abortBadRequest(c, "invalid request body")
+		return
+	}
+	ctx := c.Request.Context()
+	acc, err := s.emails.ConfirmChange(ctx, uid, req.Email, req.Code)
+	if err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	r := s.profileResponse(ctx, acc)
+	c.JSON(http.StatusOK, linkResultResponse{Status: "changed", Profile: &r})
+}
+
 // handleLinkEmailConfirm verifies the code and binds a free email or reports a
 // required merge.
 func (s *Server) handleLinkEmailConfirm(c *gin.Context) {
@@ -149,6 +239,48 @@ func (s *Server) handleLinkTelegramMerge(c *gin.Context) {
 	c.JSON(http.StatusOK, s.mergeResultResponse(c, res))
 }
 
+// handleLinkVK attaches a gateway-validated VK identity to the caller or reports a
+// required merge.
+func (s *Server) handleLinkVK(c *gin.Context) {
+	uid, ok := userID(c)
+	if !ok {
+		abortBadRequest(c, "missing identity")
+		return
+	}
+	var req linkVKBody
+	if err := c.ShouldBindJSON(&req); err != nil || req.ExternalID == "" {
+		abortBadRequest(c, "missing external_id")
+		return
+	}
+	res, err := s.links.ConfirmVK(c.Request.Context(), uid, req.ExternalID)
+	if err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, s.confirmResultResponse(c, uid, res))
+}
+
+// handleLinkVKMerge merges the account owning a gateway-validated VK identity into
+// the caller's.
+func (s *Server) handleLinkVKMerge(c *gin.Context) {
+	uid, ok := userID(c)
+	if !ok {
+		abortBadRequest(c, "missing identity")
+		return
+	}
+	var req linkVKBody
+	if err := c.ShouldBindJSON(&req); err != nil || req.ExternalID == "" {
+		abortBadRequest(c, "missing external_id")
+		return
+	}
+	res, err := s.links.MergeVK(c.Request.Context(), uid, req.ExternalID)
+	if err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, s.mergeResultResponse(c, res))
+}
+
 // confirmResultResponse renders a confirm step: a merge preview (secondary summary)
 // or a completed link (the active account's refreshed profile).
 func (s *Server) confirmResultResponse(c *gin.Context, activeID uuid.UUID, res link.ConfirmResult) linkResultResponse {

backend/internal/server/handlers_user.go

@@ -25,6 +25,10 @@ func (s *Server) handleProfile(c *gin.Context) {
 		s.abortErr(c, err)
 		return
 	}
+	// The SPA fetches the profile once per cold app-load, so stamp the account's last
+	// login time and client IP here (throttled to at most once an hour). Best-effort: it
+	// feeds the deletion dossier, never blocks the profile read.
+	_ = s.accounts.StampLastLogin(c.Request.Context(), uid, clientIP(c))
 	c.JSON(http.StatusOK, s.profileResponse(c.Request.Context(), acc))
 }
 

deploy/.env.example

@@ -1,6 +1,10 @@
 # Environment for deploy/docker-compose.yml. The CI deploy job (ci.yaml) maps the
 # Gitea TEST_-prefixed secrets/variables onto these unprefixed names; the prod
-# deploy maps the PROD_-prefixed set the same way. Copy to deploy/.env for a local run.
+# deploy maps the PROD_-prefixed set the same way. Values that are identical on every
+# contour (DICT_VERSION, SMTP_RELAY_HOST/PORT/TLS/USER/PASS, GRAFANA_SMTP_PORT,
+# VITE_VK_APP_LINK/ID, the two VK secrets) live as ONE unprefixed Gitea entry, and the
+# deploy derives TELEGRAM_MINIAPP_URL / GRAFANA_ROOT_URL / VITE_VK_ID_REDIRECT_URL from
+# PUBLIC_BASE_URL. Copy to deploy/.env for a local run (set the derived ones directly).
 #
 # Full reference (required vs optional, defaults, secret-vs-variable): deploy/README.md.
 
@@ -15,8 +19,9 @@ POSTGRES_PASSWORD=change-me            # required
 # boot the dawg-data volume preserves versions uploaded through the admin console and
 # the active version lives in the DB. On a live volume a changed value is ignored (the
 # recorded .seed_version marker wins — the seed-drift guard); change a running
-# contour's dictionary through /_gm/dictionary (ARCHITECTURE.md §5).
-DICT_VERSION=v1.3.0
+# contour's dictionary through /_gm/dictionary (ARCHITECTURE.md §5). One shared Gitea
+# variable (DICT_VERSION) seeds both contours + pins the CI test suite.
+DICT_VERSION=v1.3.1
 
 # --- Logging ----------------------------------------------------------------
 LOG_LEVEL=info
@@ -45,6 +50,17 @@ SMTP_RELAY_PASS=                       # secret
 SMTP_RELAY_FROM=no-reply@erudit-game.ru
 PUBLIC_BASE_URL=                       # required when SMTP_RELAY_HOST is set (e.g. https://erudit-game.ru)
 
+# Operator alerts (email). The backend emails the admin on new feedback / word complaints
+# (coalesced), and Grafana emails infra alerts. Distinct senders; recipients may be several
+# comma-separated addresses. Grafana reuses SMTP_RELAY_HOST/USER/PASS but dials the STARTTLS
+# port (it can't do the backend's implicit TLS), GRAFANA_SMTP_PORT. All empty = off.
+SMTP_RELAY_ADMIN_FROM=                 # backend admin-alert From (e.g. alerts@erudit-game.ru)
+ADMIN_EMAIL=                           # backend admin-alert recipient(s), comma-separated
+SMTP_RELAY_SERVICE_FROM=               # Grafana alert From; the deploy derives a bare address for Grafana (it rejects "Name" <addr>)
+SERVICE_EMAIL=                         # Grafana alert recipient(s), comma-separated
+GRAFANA_SMTP_PORT=                     # Grafana STARTTLS port on SMTP_RELAY_HOST (Selectel: 1126)
+GF_SMTP_ENABLED=false                  # set true to enable Grafana alert emails
+
 # --- Edge / caddy -----------------------------------------------------------
 # Test: ":80" (the host caddy terminates TLS and forwards to scrabble:80 on the
 # external `edge` network). Prod: a domain so caddy does its own ACME.
@@ -57,10 +73,12 @@ VITE_TELEGRAM_BOT_ID=
 VITE_TELEGRAM_LINK=                                 # friend-invite Mini App link (full URL, e.g. https://t.me/<bot>/<app>)
 VITE_TELEGRAM_GAME_CHANNEL_NAME=                    # landing "Play in Telegram" link, the bot's game channel
 VITE_VK_APP_LINK=                                   # landing "Play on VK" link (full URL, https://vk.com/app<id>)
+VITE_VK_APP_ID=                                     # VK ID "Web" app id (client_id) for VK web-login linking; also the gateway's GATEWAY_VK_ID_APP_ID
+VITE_VK_ID_REDIRECT_URL=                            # VK ID trusted redirect URL (e.g. https://erudit-game.ru/app/); also the gateway's exchange redirect_uri. Deploy derives it as PUBLIC_BASE_URL + /app/
 VITE_GATEWAY_URL=
 
 # --- Grafana ----------------------------------------------------------------
-GRAFANA_ROOT_URL=/_gm/grafana/         # set the full https URL behind a real domain
+GRAFANA_ROOT_URL=/_gm/grafana/         # deploy derives PUBLIC_BASE_URL + /_gm/grafana/; set the full https URL for a local run
 GRAFANA_ADMIN_PASSWORD=admin
 
 # --- Telegram validator + bot -----------------------------------------------
@@ -77,7 +95,7 @@ TELEGRAM_PROMO_BOT_TOKEN=             # optional standalone promo bot token; emp
 TELEGRAM_BOT_USERNAME=               # main bot @username without the @ (promo message); required when the promo token is set
 TELEGRAM_BOT_LINK=                    # main bot Mini App link for the promo button (reuse VITE_TELEGRAM_LINK); required when the promo token is set
 TELEGRAM_PROMO_START_PARAM=           # promo button startapp payload — a variant-seed deep link (default verudit_ru-scrabble_en) adding English Scrabble for new users; empty forwards the user's /start payload
-TELEGRAM_MINIAPP_URL=                  # required
+TELEGRAM_MINIAPP_URL=                  # required; deploy derives it as PUBLIC_BASE_URL + /telegram/
 TELEGRAM_TEST_ENV=false
 TELEGRAM_API_BASE_URL=
 
@@ -86,3 +104,14 @@ TELEGRAM_API_BASE_URL=
 # launch-parameter signature in-process under it (a pure offline HMAC, no VK API call).
 # Empty disables the VK auth path (auth.vk). Set from the Gitea TEST_/PROD_ secret.
 GATEWAY_VK_APP_SECRET=
+# VK ID web login (browser VK-identity linking) — a SEPARATE VK "Web" app: the gateway runs
+# the confidential OAuth 2.1 code exchange under this protected key. The app id + redirect URL
+# come from VITE_VK_APP_ID / VITE_VK_ID_REDIRECT_URL above. All three empty disables link.vk.*.
+GATEWAY_VK_ID_CLIENT_SECRET=
+
+# --- Gateway anti-abuse ------------------------------------------------------
+# Planted honeytoken bearer value: any request presenting it is flagged — a 24h IP ban
+# where the IP ban is on (prod), logs + a ban metric otherwise (test). Plant the value
+# somewhere an attacker would find it; empty disables the trap. Gitea
+# TEST_/PROD_GATEWAY_HONEYTOKEN (secret).
+GATEWAY_HONEYTOKEN=

deploy/README.md

@@ -46,6 +46,18 @@ runs `docker compose up -d --build` on the runner host. The prod deploy maps the
 **`PROD_`** set the same way. So a Gitea secret named `TEST_POSTGRES_PASSWORD`
 feeds the compose's `POSTGRES_PASSWORD`, etc.
 
+Three naming classes in Gitea:
+- **Per-contour** (`TEST_`/`PROD_<NAME>`) — values that differ between the contours
+  (bots, hosts, public origin, log level, email senders): the common case below.
+- **Shared** (one unprefixed `<NAME>`, no prefix) — values identical on every contour,
+  stored once: `DICT_VERSION`, `SMTP_RELAY_HOST`/`PORT`/`TLS`/`USER`/`PASS`,
+  `GRAFANA_SMTP_PORT`, `VITE_VK_APP_LINK`, `VITE_VK_APP_ID`, `GATEWAY_VK_APP_SECRET`,
+  `GATEWAY_VK_ID_CLIENT_SECRET` (one Selectel relay + one pair of VK apps for all contours).
+- **Derived** — not stored at all; the deploy computes them from `PUBLIC_BASE_URL`
+  (`deploy/write-prod-env.sh`, and the `ci.yaml` deploy step): `TELEGRAM_MINIAPP_URL`
+  (`+ /telegram/`), `GRAFANA_ROOT_URL` (`+ /_gm/grafana/`), `VITE_VK_ID_REDIRECT_URL`
+  (`+ /app/`). Set them directly only for a local `.env` run.
+
 The deploy job also **seeds the config files** (`caddy`, `otelcol`, `prometheus`,
 `tempo`, `grafana`) to a stable host path (`$HOME/.scrabble-deploy`) and sets
 `SCRABBLE_CONFIG_DIR` to it before `up`. The runner's checkout is an ephemeral act
@@ -62,7 +74,7 @@ compose binds from this directory.
 | --- | --- | --- |
 | `POSTGRES_PASSWORD` | secret | Postgres password (also embedded in `BACKEND_POSTGRES_DSN`). |
 | `GM_BASICAUTH_HASH` | secret | bcrypt hash gating `/_gm` (admin console + Grafana). Generate with `docker run --rm caddy:2-alpine caddy hash-password --plaintext '<pw>'`. |
-| `TELEGRAM_MINIAPP_URL` | variable | The Mini App URL the bot hands out in deep links / buttons. |
+| `TELEGRAM_MINIAPP_URL` | derived | The Mini App URL the bot hands out in deep links / buttons. The deploy derives `PUBLIC_BASE_URL + /telegram/`; set it directly only for a local run (compose still `:?`-requires it). |
 | `EXPORT_SIGN_KEY` | secret | HMAC key signing the public finished-game export download URLs (`/dl/*`). Generate with `openssl rand -base64 32`. |
 
 **Plus the bot token** — `TELEGRAM_BOT_TOKEN` (secret), shared by the validator (HMAC
@@ -82,11 +94,11 @@ without it Docker's resolver handles `otelcol`, `gateway` and `api.telegram.org`
 | --- | --- | --- | --- |
 | `POSTGRES_DB` | variable | `scrabble` | Database name. |
 | `POSTGRES_USER` | variable | `scrabble` | Database user. |
-| `DICT_VERSION` | variable | `v1.3.0` | `scrabble-dictionary` release tag baked into the backend image as the **seed for a fresh volume** (build-arg). A live contour changes dictionary through the admin console, not this; on a seeded volume a changed value is ignored (the recorded `.seed_version` marker wins — the seed-drift guard, ARCHITECTURE.md §5). Set per contour as `TEST_`/`PROD_DICT_VERSION`. |
+| `DICT_VERSION` | variable (shared) | `v1.3.1` | `scrabble-dictionary` release tag baked into the backend image as the **seed for a fresh volume** (build-arg). A live contour changes dictionary through the admin console, not this; on a seeded volume a changed value is ignored (the recorded `.seed_version` marker wins — the seed-drift guard, ARCHITECTURE.md §5). One shared unprefixed Gitea variable seeds both contours and pins the CI test suite. |
 | `LOG_LEVEL` | variable | `info` | Shared log level for backend / gateway / validator / bot (`debug\|info\|warn\|error`). |
 | `CADDY_SITE_ADDRESS` | variable | `:80` | Caddy site address. Test: `:80` (host caddy terminates TLS). Prod: a domain, so caddy does its own ACME. |
 | `GM_BASICAUTH_USER` | variable | `gm` | Username for the `/_gm` Basic-Auth. |
-| `GRAFANA_ROOT_URL` | variable | `/_gm/grafana/` | Grafana root URL (sub-path serving). Set the full `https://<domain>/_gm/grafana/` behind a real domain. |
+| `GRAFANA_ROOT_URL` | derived | `/_gm/grafana/` | Grafana root URL (sub-path serving). The deploy derives `PUBLIC_BASE_URL + /_gm/grafana/`; set the full `https://<domain>/_gm/grafana/` only for a local run. |
 | `GRAFANA_ADMIN_PASSWORD` | secret | `admin` | Grafana admin password. Low impact (the login form is disabled, access is anonymous-admin behind caddy) but set it anyway. |
 | `TELEGRAM_GAME_CHANNEL_ID` | variable | _(empty)_ | The bot's game-channel id; empty/`0` disables channel posts. |
 | `TELEGRAM_TEST_ENV` | _pinned_ | `false` | `true` routes the bot through Telegram's test environment (`.../bot<token>/test/METHOD`). **The CI test contour pins this to `true` in `ci.yaml`** (the contour is the test environment) — it is not a Gitea variable. Set it in `.env` for a local run; prod leaves it `false`. |
@@ -94,15 +106,26 @@ without it Docker's resolver handles `otelcol`, `gateway` and `api.telegram.org`
 | `VITE_TELEGRAM_BOT_ID` | variable | _(empty)_ | UI build-arg: numeric bot id for the web Login Widget. |
 | `VITE_TELEGRAM_LINK` | variable | _(empty)_ | UI build-arg: friend-invite Mini App link (full URL, `https://t.me/<bot>/<app>` — `<app>` is the Mini App short name from BotFather). |
 | `VITE_TELEGRAM_GAME_CHANNEL_NAME` | variable | _(empty)_ | UI build-arg: the landing "Play in Telegram" link, the bot's game channel (e.g. `https://t.me/Erudit_Game`). |
-| `VITE_VK_APP_LINK` | variable | _(empty)_ | UI build-arg: the landing "Play on VK" link, the VK Mini App (full URL, `https://vk.com/app<id>`). |
+| `VITE_VK_APP_LINK` | variable (shared) | _(empty)_ | UI build-arg: the landing "Play on VK" link, the VK Mini App (full URL, `https://vk.com/app<id>`). One VK Mini App for all contours. |
+| `VITE_VK_APP_ID` | variable (shared) | _(empty)_ | VK ID "Web" app id (`client_id`) for VK web-login linking. Baked into the SPA authorize URL and reused as the gateway's `GATEWAY_VK_ID_APP_ID`. Empty disables the `link.vk.*` ops. One VK ID "Web" app for all contours. |
+| `VITE_VK_ID_REDIRECT_URL` | derived | _(empty)_ | VK ID trusted redirect URL — must match the app's registered redirect exactly. The deploy derives `PUBLIC_BASE_URL + /app/` (used by the SPA and as the gateway's exchange `redirect_uri`); set it only for a local run. |
+| `GATEWAY_VK_APP_SECRET` | secret (shared) | _(empty)_ | The VK Mini App's protected key (`client_secret`): the gateway verifies the launch-parameter signature in-process under it (offline HMAC, no VK API call). Empty disables the VK auth path (`auth.vk`). One VK Mini App for all contours. |
+| `GATEWAY_VK_ID_CLIENT_SECRET` | secret (shared) | _(empty)_ | The VK ID "Web" app's protected key (`client_secret`) for the gateway's server-side confidential code exchange. A SEPARATE VK app from `GATEWAY_VK_APP_SECRET` (the Mini App). One VK ID "Web" app for all contours. |
+| `GATEWAY_HONEYTOKEN` | secret | _(empty)_ | Planted honeytoken bearer value: presenting it earns a 24h IP ban + a high-severity alarm where the IP ban is on (prod), or logs + a `gateway_abuse_banned_total{reason="honeytoken"}` metric (test, ban off). Plant the value somewhere an attacker would find it; empty disables the trap. Per-contour `TEST_`/`PROD_GATEWAY_HONEYTOKEN`. |
 | `VITE_GATEWAY_URL` | variable | _(empty)_ | UI build-arg: gateway origin; empty = same-origin (the usual single-origin deploy). |
-| `SMTP_RELAY_HOST` | variable | _(empty)_ | Selectel SMTP relay host for confirm-code email. Empty leaves the backend on the log mailer (email disabled) — the contour still boots. One relay for every contour (limit 100 msgs / 5 min). |
-| `SMTP_RELAY_PORT` | variable | `465` | Relay port. No client certificate is needed (the server cert is validated against the system roots). |
-| `SMTP_RELAY_TLS` | variable | _(empty)_ | Transport security: `ssl` (implicit TLS) or `starttls`. Empty derives it from the port (implicit on `465`, STARTTLS otherwise); required for a relay on a non-standard port (e.g. Selectel's `1127` = SSL, `1126` = STARTTLS). |
-| `SMTP_RELAY_USER` | secret | _(empty)_ | Relay SMTP AUTH username. |
-| `SMTP_RELAY_PASS` | secret | _(empty)_ | Relay SMTP AUTH password. |
+| `SMTP_RELAY_HOST` | variable (shared) | _(empty)_ | Selectel SMTP relay host for confirm-code email. Empty leaves the backend on the log mailer (email disabled) — the contour still boots. One relay for every contour (limit 100 msgs / 5 min). |
+| `SMTP_RELAY_PORT` | variable (shared) | `465` | Relay port. No client certificate is needed (the server cert is validated against the system roots). |
+| `SMTP_RELAY_TLS` | variable (shared) | _(empty)_ | Transport security: `ssl` (implicit TLS) or `starttls`. Empty derives it from the port (implicit on `465`, STARTTLS otherwise); required for a relay on a non-standard port (e.g. Selectel's `1127` = SSL, `1126` = STARTTLS). |
+| `SMTP_RELAY_USER` | secret (shared) | _(empty)_ | Relay SMTP AUTH username. |
+| `SMTP_RELAY_PASS` | secret (shared) | _(empty)_ | Relay SMTP AUTH password. |
 | `SMTP_RELAY_FROM` | variable | `no-reply@localhost` | Sender address. **Must use the prod domain** (`no-reply@erudit-game.ru`) — Selectel only accepts the verified sender domain — so it is the same on every contour. |
 | `PUBLIC_BASE_URL` | variable | _(empty)_ | Canonical public https origin for links in the email (the contour's own URL, e.g. `https://erudit-game.ru`). **Required by the backend whenever `SMTP_RELAY_HOST` is set** — it is never derived from a request Host header (anti-injection). |
+| `SMTP_RELAY_ADMIN_FROM` | variable | _(empty)_ | Backend operator-alert sender (new feedback / word complaints), distinct from the confirm-code From. Empty (with `ADMIN_EMAIL`) disables the alert worker. |
+| `ADMIN_EMAIL` | variable | _(empty)_ | Backend operator-alert recipient(s); several comma-separated addresses allowed. |
+| `SMTP_RELAY_SERVICE_FROM` | variable | _(empty)_ | Grafana infra-alert sender address. |
+| `SERVICE_EMAIL` | variable | _(empty)_ | Grafana infra-alert recipient(s); comma-separated allowed (read by the provisioned contact point via `$__env{SERVICE_EMAIL}`). |
+| `GRAFANA_SMTP_PORT` | variable (shared) | _(empty)_ | STARTTLS port Grafana dials on `SMTP_RELAY_HOST` (its client can't do the backend's implicit TLS), e.g. Selectel's `1126`. Reuses `SMTP_RELAY_HOST`/`USER`/`PASS`. |
+| `GF_SMTP_ENABLED` | variable | `false` | Set `true` to enable Grafana alert emails. |
 
 The six `VITE_*` are **build-args** baked into the gateway and landing images at
 build time (both targets share one UI build stage — keep the args identical so it is
@@ -132,14 +155,13 @@ intentionally **unset** — caddy owns `/_gm` in the contour.
 
 The dictionary ships as a versioned **release artifact** (`scrabble-dawg-vX.Y.Z.tar.gz`) from
 [`scrabble-dictionary`](https://gitea.iliadenisov.ru/developer/scrabble-dictionary). The tag is
-a build-time input with **no default** in the images, so it is set in exactly two places to
-move the whole stack — change both to a new release:
+a build-time input with **no default** in the images. It is a single Gitea repo variable —
+**`DICT_VERSION`** (unprefixed, shared across contours) — so a release bump is **one edit**:
 
-1. **CI tests** — `.gitea/workflows/ci.yaml` `env.DICT_VERSION` (the unit/integration jobs
-   download that dawg).
-2. **Deploy seed** — the Gitea repo variables `TEST_DICT_VERSION` / `PROD_DICT_VERSION` (the tag
-   the deploy bakes into a **fresh** volume's image; the deploy job feeds it to `compose` as
-   `DICT_VERSION`).
+- the CI test jobs read it via `.gitea/workflows/ci.yaml`'s top-level
+  `env.DICT_VERSION: ${{ vars.DICT_VERSION }}` (the unit/integration jobs download that dawg), and
+- both deploy jobs feed the same variable to `compose` as the `DICT_VERSION` build-arg that
+  bakes a **fresh** volume's seed.
 
 For local builds set `DICT_VERSION` in `deploy/.env` (template: `.env.example`); a bare
 `docker build` needs `--build-arg DICT_VERSION=vX.Y.Z`. The Dockerfiles and `compose` carry no
@@ -168,6 +190,16 @@ public site. After `master` is green this workflow is the **only** thing that to
 prod — nothing auto-deploys there. It runs four visible jobs: **build → deploy-main →
 deploy-bot → verify** (the per-service rolling shows in the deploy-main log).
 
+**Maintenance page.** During the roll (and any migration window) `prod-deploy.sh` raises a
+flag the edge caddy serves a static 503 "технические работы" page from
+(`deploy/caddy/maintenance.html`), for the user-facing routes only — `/_gm` (Grafana) stays
+reachable. The flag is cleared on any exit (success, a health failure + rollback, or an
+error) by a shell trap, so it can never stick on. It arms from this feature's own deploy
+onward (the caddy carrying the gate must be live first). This is **not** a zero-downtime
+deploy — the backend is a single stateful instance (in-memory game state + push hub, no
+Redis), so its swap still blips (clients auto-reconnect the live stream); the page just
+makes the window graceful instead of raw 502s.
+
 **Versioning.** Each release is a git tag `vX.Y.Z` on `master`; the deploy stamps
 `git describe --tags` into every image tag, every binary (`-ldflags` → `pkg/version` →
 the `service.version` telemetry attribute) and the SPA About screen. Tag the release
@@ -200,18 +232,31 @@ together with the fresh CA.
 **Sizing / monitoring:** the main host launches undersized (2 vCPU / 1.9 GiB); the prod
 overlay trims limits + `GOMAXPROCS=2` + 7d Prometheus retention, and `node_exporter` feeds
 host memory to Grafana (`/_gm/grafana/`). Watch host memory and resize at Selectel when
-players arrive.
+players arrive. The per-container memory caps are enforced (Compose v2 → cgroup), so no one
+service can eat all RAM, but they **overcommit** the host (~2.8 GiB of caps vs 1.9 GiB) — a
+**1 GiB swap file** (Ansible `common` role, `swap_size`, `vm.swappiness=10`) cushions a
+simultaneous spike into swap instead of the kernel OOM-killer. The `host_mem_low` Grafana
+alert fires under 10% available.
 
-**`PROD_` Gitea set** (mirrors `TEST_`, mapped onto the unprefixed names above) — secrets:
+**Shared Gitea set** (one unprefixed entry each, used by every contour) — secrets:
+`GATEWAY_VK_APP_SECRET, GATEWAY_VK_ID_CLIENT_SECRET, SMTP_RELAY_USER, SMTP_RELAY_PASS`;
+variables: `DICT_VERSION, SMTP_RELAY_HOST, SMTP_RELAY_PORT, SMTP_RELAY_TLS, GRAFANA_SMTP_PORT,
+VITE_VK_APP_LINK, VITE_VK_APP_ID`. **Derived from `PUBLIC_BASE_URL` at deploy** (not stored):
+`TELEGRAM_MINIAPP_URL, GRAFANA_ROOT_URL, VITE_VK_ID_REDIRECT_URL`.
+
+**`PROD_` Gitea set** (per-contour, mirrors `TEST_`, mapped onto the unprefixed names above)
+— secrets:
 `PROD_{POSTGRES_PASSWORD, GM_BASICAUTH_HASH, GRAFANA_ADMIN_PASSWORD, TELEGRAM_BOT_TOKEN,
-TELEGRAM_PROMO_BOT_TOKEN, EXPORT_SIGN_KEY, REGISTRY_PASSWORD, SSH_KEY, SSH_KNOWN_HOSTS, BOTLINK_CA,
-BOTLINK_GATEWAY_CERT, BOTLINK_GATEWAY_KEY, BOTLINK_BOT_CERT, BOTLINK_BOT_KEY,
-SMTP_RELAY_USER, SMTP_RELAY_PASS}`; variables:
-`PROD_{REGISTRY_USER, MAIN_HOST, TG_HOST, CADDY_SITE_ADDRESS, GM_BASICAUTH_USER,
-GRAFANA_ROOT_URL, LOG_LEVEL, DICT_VERSION, TELEGRAM_MINIAPP_URL, TELEGRAM_GAME_CHANNEL_ID,
-TELEGRAM_CHAT_ID, TELEGRAM_BOT_USERNAME, VITE_TELEGRAM_BOT_ID, VITE_TELEGRAM_LINK,
-VITE_TELEGRAM_GAME_CHANNEL_NAME, VITE_VK_APP_LINK,
-SMTP_RELAY_HOST, SMTP_RELAY_PORT, SMTP_RELAY_TLS, SMTP_RELAY_FROM, PUBLIC_BASE_URL}`.
+TELEGRAM_PROMO_BOT_TOKEN, EXPORT_SIGN_KEY, GATEWAY_HONEYTOKEN, REGISTRY_PASSWORD, SSH_KEY,
+SSH_KNOWN_HOSTS, BOTLINK_CA, BOTLINK_GATEWAY_CERT, BOTLINK_GATEWAY_KEY, BOTLINK_BOT_CERT,
+BOTLINK_BOT_KEY}`; variables:
+`PROD_{REGISTRY_USER, MAIN_HOST, TG_HOST, CADDY_SITE_ADDRESS, GM_BASICAUTH_USER, LOG_LEVEL,
+TELEGRAM_GAME_CHANNEL_ID, TELEGRAM_CHAT_ID, TELEGRAM_SUPPORT_CHAT_ID, TELEGRAM_BOT_USERNAME,
+VITE_TELEGRAM_BOT_ID, VITE_TELEGRAM_LINK, VITE_TELEGRAM_GAME_CHANNEL_NAME, SMTP_RELAY_FROM,
+PUBLIC_BASE_URL, SMTP_RELAY_ADMIN_FROM, ADMIN_EMAIL, SMTP_RELAY_SERVICE_FROM, SERVICE_EMAIL,
+GF_SMTP_ENABLED}`. The test contour uses the same names under `TEST_`, minus the prod-only
+infra (`MAIN_HOST`/`TG_HOST`/`REGISTRY_*`/`SSH_*`/`BOTLINK_*`, which the test deploy generates
+or runs locally) and plus `TEST_AWG_CONF` (the bot's VPN egress).
 
 ## Host-side setup (outside this repo)
 

deploy/ansible/group_vars/all.yml

@@ -19,3 +19,11 @@ scrabble_base_dir: /opt/scrabble
 # the host's own containers (and any ad-hoc runs) rotate identically.
 docker_log_max_size: "10m"
 docker_log_max_file: "3"
+
+# Swap file as an OOM cushion. The per-container memory caps (docker-compose.prod.yml)
+# sum to more than the tight main host's RAM (2 vCPU / 1.9 GiB), so a simultaneous
+# spike could otherwise hit the kernel OOM-killer and it might pick postgres. A small
+# swap absorbs the overshoot; swappiness stays low so swap is a cushion, not a hot
+# path (a slow service beats a killed one). Set swap_size to "0" to skip provisioning.
+swap_size: "1G"
+swap_swappiness: 10

deploy/ansible/roles/common/tasks/main.yml

@@ -150,6 +150,57 @@
     enabled: true
     state: started
 
+# --- Swap file (OOM cushion) ---------------------------------------------------
+# The prod main host is tight (1.9 GiB) and the per-container memory caps
+# (docker-compose.prod.yml) sum to more than RAM, so a simultaneous spike could hit
+# the kernel OOM-killer (which might pick postgres). A small swap absorbs the
+# overshoot. Idempotent; skipped when swap_size == "0". Builtin-only (no ansible.posix).
+
+- name: Check whether the swap file is already active
+  ansible.builtin.command: swapon --show=NAME --noheadings
+  register: swap_active
+  changed_when: false
+  when: swap_size != "0"
+
+- name: Allocate the swap file
+  ansible.builtin.command:
+    cmd: "fallocate -l {{ swap_size }} /swapfile"
+    creates: /swapfile
+  when: swap_size != "0" and '/swapfile' not in swap_active.stdout
+
+- name: Secure the swap file (0600)
+  ansible.builtin.file:
+    path: /swapfile
+    owner: root
+    group: root
+    mode: "0600"
+  when: swap_size != "0"
+
+- name: Format and enable the swap file
+  ansible.builtin.shell: "mkswap /swapfile && swapon /swapfile"
+  when: swap_size != "0" and '/swapfile' not in swap_active.stdout
+
+- name: Persist the swap file in /etc/fstab
+  ansible.builtin.lineinfile:
+    path: /etc/fstab
+    line: "/swapfile none swap sw 0 0"
+    regexp: '^/swapfile\s'
+    state: present
+  when: swap_size != "0"
+
+- name: Keep swap a cushion, not a hot path (low swappiness)
+  ansible.builtin.copy:
+    dest: /etc/sysctl.d/60-scrabble-swap.conf
+    mode: "0644"
+    content: "vm.swappiness = {{ swap_swappiness }}\n"
+  register: swappiness_conf
+  when: swap_size != "0"
+
+- name: Apply swappiness now
+  ansible.builtin.command: sysctl --system
+  changed_when: false
+  when: swap_size != "0" and swappiness_conf is changed
+
 # --- Deploy directories --------------------------------------------------------
 
 - name: Create the scrabble base directories

deploy/blackbox/blackbox.yml

@@ -0,0 +1,14 @@
+# blackbox_exporter probe modules. tls_cert opens a verified TLS connection to the edge
+# caddy so Prometheus can read probe_ssl_earliest_cert_expiry — the signal behind the
+# certificate-renewal-failure alert. The SNI is the production public host, whose cert the
+# edge caddy serves once it does its own ACME; on the test contour caddy is HTTP-only
+# (behind the host caddy), so the probe finds nothing on :443 and the cert metric is absent.
+modules:
+  tls_cert:
+    prober: tcp
+    timeout: 5s
+    tcp:
+      tls: true
+      tls_config:
+        server_name: erudit-game.ru
+        insecure_skip_verify: false

deploy/caddy/Caddyfile

@@ -33,6 +33,39 @@
 	# is the prod fix. Background + alternatives (incl. serving h3 for real): docs/EDGE_HTTP3.md.
 	header Alt-Svc clear
 
+	# Maintenance gate. While the deploy holds the flag file /srv/maint/on (touched by
+	# prod-deploy.sh around a rolling swap, removed on the script's exit), serve a static
+	# 503 "works in progress" page instead of proxying to a mid-recreate upstream —
+	# a graceful signal rather than raw 502s. Operator surfaces (/_gm) are excluded so
+	# Grafana stays reachable during the window. Caddy stat()s the flag per request, so
+	# toggling it needs no reload; the page + flag live in the caddy config dir bind-mounted
+	# read-only at /srv/maint (docker-compose.yml). The test contour never sets the flag
+	# (only prod-deploy.sh does), so this is inert there.
+	@maintenance {
+		not path /_gm /_gm/*
+		file {
+			root /srv/maint
+			try_files on
+		}
+	}
+	handle @maintenance {
+		error 503
+	}
+	handle_errors {
+		@maint503 expression {err.status_code} == 503
+		handle @maint503 {
+			root * /srv/maint
+			rewrite * /maintenance.html
+			header Retry-After 120
+			# Distinctive maintenance marker so the SPA can tell a planned window apart from
+			# a transient upstream 503 and show its own dimmed overlay (an in-session user
+			# never sees this static page — it only renders on a fresh load). The header
+			# rides every gated response, incl. the Connect/gRPC edge the app polls.
+			header X-Scrabble-Maintenance 1
+			file_server
+		}
+	}
+
 	# Operator surfaces under /_gm: a single shared Basic-Auth, then route.
 	@gm path /_gm /_gm/*
 	handle @gm {
@@ -53,7 +86,7 @@
 	# The game SPA and the Connect edge are served by the gateway. Strip any
 	# client-supplied X-Scrabble-Honeypot here so the gateway only ever honours the
 	# tag the honeypot block sets below (a client cannot self-tag a real request).
-	@gateway path /app /app/* /telegram /telegram/* /vk /vk/* /dict/* /dl/* /metrics/* /scrabble.edge.v1.Gateway/*
+	@gateway path /app /app/* /telegram /telegram/* /vk /vk/* /dict/* /dl/* /metrics/* /telemetry/* /scrabble.edge.v1.Gateway/*
 	handle @gateway {
 		reverse_proxy gateway:8081 {
 			header_up -X-Scrabble-Honeypot

deploy/caddy/maintenance.html

@@ -0,0 +1,44 @@
+<!doctype html>
+<!--
+  Served with 503 by the edge caddy while the deploy holds the maintenance flag
+  (/srv/maint/on, toggled by deploy/prod-deploy.sh around a rolling swap). Static and
+  self-contained (no upstream, no external assets) so it renders while the backend /
+  gateway are mid-recreate.
+-->
+<html lang="ru">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <meta name="robots" content="noindex">
+  <title>Эрудит — технические работы</title>
+  <style>
+    :root { color-scheme: light dark; }
+    html, body { height: 100%; margin: 0; }
+    body {
+      display: flex; align-items: center; justify-content: center;
+      font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
+      background: #f4f1ea; color: #2b2b2b;
+      padding: 24px; box-sizing: border-box;
+    }
+    @media (prefers-color-scheme: dark) { body { background: #1d1b17; color: #e8e4da; } }
+    .card { max-width: 30rem; text-align: center; line-height: 1.5; }
+    .tile {
+      display: inline-block; width: 3.5rem; height: 3.5rem; line-height: 3.5rem;
+      font-size: 2rem; font-weight: 700; border-radius: 10px;
+      background: #d9b451; color: #2b2b2b; box-shadow: 0 2px 4px rgba(0,0,0,.25);
+      margin-bottom: 1.25rem;
+    }
+    h1 { font-size: 1.4rem; margin: 0 0 .5rem; }
+    p { margin: .35rem 0; }
+    .en { opacity: .7; font-size: .95rem; }
+  </style>
+</head>
+<body>
+  <main class="card">
+    <div class="tile">Э</div>
+    <h1>Технические работы</h1>
+    <p>Идёт короткое обновление игры. Мы скоро вернёмся — обновите страницу через пару минут.</p>
+    <p class="en">Scrabble is briefly down for an update. Please refresh in a couple of minutes.</p>
+  </main>
+</body>
+</html>

deploy/docker-compose.yml

@@ -151,6 +151,10 @@ services:
       BACKEND_SMTP_PASSWORD: ${SMTP_RELAY_PASS:-}
       BACKEND_SMTP_FROM: ${SMTP_RELAY_FROM:-no-reply@localhost}
       BACKEND_PUBLIC_BASE_URL: ${PUBLIC_BASE_URL:-}
+      # Operator alert emails (new feedback / word complaints): a distinct sender and the
+      # recipient(s) (comma-separated allowed). Both empty disables the alert worker.
+      BACKEND_SMTP_ADMIN_FROM: ${SMTP_RELAY_ADMIN_FROM:-}
+      BACKEND_ADMIN_EMAIL: ${ADMIN_EMAIL:-}
     # The dictionary lives on a named volume seeded from the image on first boot
     # (the image's /opt/dawg is owned by the nonroot UID, which the fresh volume
     # inherits). The admin console writes new version subdirectories here, and the
@@ -186,6 +190,8 @@ services:
         VITE_TELEGRAM_LINK: ${VITE_TELEGRAM_LINK:-}
         VITE_TELEGRAM_GAME_CHANNEL_NAME: ${VITE_TELEGRAM_GAME_CHANNEL_NAME:-}
         VITE_VK_APP_LINK: ${VITE_VK_APP_LINK:-}
+        VITE_VK_APP_ID: ${VITE_VK_APP_ID:-}
+        VITE_VK_ID_REDIRECT_URL: ${VITE_VK_ID_REDIRECT_URL:-}
         VITE_GATEWAY_URL: ${VITE_GATEWAY_URL:-}
         VITE_APP_VERSION: ${APP_VERSION:-dev}
         # Go binary version (the SPA's VITE_APP_VERSION is the same git tag).
@@ -203,6 +209,14 @@ services:
       # app's protected key (a pure offline HMAC, no VK API round-trip). Empty disables
       # the VK auth path (auth.vk is then unregistered).
       GATEWAY_VK_APP_SECRET: ${GATEWAY_VK_APP_SECRET:-}
+      # VK ID web login (browser VK-identity linking): the confidential OAuth 2.1 code
+      # exchange runs server-side under the VK ID "Web" app's protected key. This is a
+      # SEPARATE VK app from the Mini App above, so the credentials are distinct. The app id
+      # and redirect URL are the same values the SPA builds its authorize URL from (one
+      # source each). All three empty disables the link.vk.* ops.
+      GATEWAY_VK_ID_APP_ID: ${VITE_VK_APP_ID:-}
+      GATEWAY_VK_ID_CLIENT_SECRET: ${GATEWAY_VK_ID_CLIENT_SECRET:-}
+      GATEWAY_VK_ID_REDIRECT_URL: ${VITE_VK_ID_REDIRECT_URL:-}
       # The reverse bot-link: the bot dials :9443 over mTLS; the backend admin relay
       # reaches the gateway at :9092 (plaintext, internal). In the test contour both
       # listeners stay on the internal network (the bot shares the VPN netns); in prod
@@ -213,10 +227,12 @@ services:
       GATEWAY_BOTLINK_TLS_KEY: /certs/gateway.key
       GATEWAY_BOTLINK_TLS_CA: /certs/ca.crt
       # Anti-abuse IP ban (fail2ban-style), fed by rate-limit rejections and the
-      # honeypot/honeytoken. Off by default: it bans by client IP, which is only
-      # real in prod — the test contour arrives as one shared NAT address, so a ban
-      # there would be self-inflicted (the honeypot/honeytoken still log). Prod sets
-      # these from PROD_ inputs; GATEWAY_HONEYTOKEN is the planted bearer trap.
+      # honeypot/honeytoken. Off by default: it bans by client IP, which is only real
+      # in prod — the test contour arrives as one shared NAT address, so a ban there
+      # would be self-inflicted (the honeypot still logs). The prod deploy forces it on
+      # in env.sh (deploy/write-prod-env.sh), not via a Gitea variable. GATEWAY_HONEYTOKEN
+      # is the planted bearer trap, fed from the per-contour TEST_/PROD_GATEWAY_HONEYTOKEN
+      # secret; empty (unset secret) leaves the trap off.
       GATEWAY_ABUSE_BAN_ENABLED: ${GATEWAY_ABUSE_BAN_ENABLED:-false}
       GATEWAY_HONEYTOKEN: ${GATEWAY_HONEYTOKEN:-}
       GATEWAY_LOG_LEVEL: ${LOG_LEVEL:-info}
@@ -260,6 +276,8 @@ services:
         VITE_TELEGRAM_LINK: ${VITE_TELEGRAM_LINK:-}
         VITE_TELEGRAM_GAME_CHANNEL_NAME: ${VITE_TELEGRAM_GAME_CHANNEL_NAME:-}
         VITE_VK_APP_LINK: ${VITE_VK_APP_LINK:-}
+        VITE_VK_APP_ID: ${VITE_VK_APP_ID:-}
+        VITE_VK_ID_REDIRECT_URL: ${VITE_VK_ID_REDIRECT_URL:-}
         VITE_GATEWAY_URL: ${VITE_GATEWAY_URL:-}
         VITE_APP_VERSION: ${APP_VERSION:-dev}
     restart: unless-stopped
@@ -410,6 +428,11 @@ services:
       GM_BASICAUTH_HASH: ${GM_BASICAUTH_HASH:?set GM_BASICAUTH_HASH}
     volumes:
       - ${SCRABBLE_CONFIG_DIR:-.}/caddy/Caddyfile:/etc/caddy/Caddyfile:ro
+      # Maintenance page + toggle flag: the caddy config dir holds maintenance.html and the
+      # `on` flag prod-deploy.sh touches around a rolling swap; the Caddyfile serves a 503
+      # from here while the flag exists (read-only mount — the deploy writes the flag on the
+      # host side). See deploy/caddy/Caddyfile and deploy/prod-deploy.sh.
+      - ${SCRABBLE_CONFIG_DIR:-.}/caddy:/srv/maint:ro
       - caddy-data:/data
     deploy:
       resources:
@@ -497,6 +520,21 @@ services:
       # caddy's Basic-Auth and re-prompts for the password on every dashboard; the
       # dashboards poll and do not need Live.
       GF_LIVE_MAX_CONNECTIONS: "0"
+      # SMTP for alert emails, reusing the shared relay host + credentials + the SERVICE
+      # From/recipient. Grafana's client speaks STARTTLS (not the backend's implicit-TLS
+      # port), so it dials the relay host on its STARTTLS port (GRAFANA_SMTP_PORT).
+      # Disabled unless GF_SMTP_ENABLED.
+      GF_SMTP_ENABLED: ${GF_SMTP_ENABLED:-false}
+      GF_SMTP_HOST: ${SMTP_RELAY_HOST:-}:${GRAFANA_SMTP_PORT:-}
+      GF_SMTP_USER: ${SMTP_RELAY_USER:-}
+      GF_SMTP_PASSWORD: ${SMTP_RELAY_PASS:-}
+      # A BARE address (Grafana rejects the "Name" <addr> form); the deploy derives it from
+      # SMTP_RELAY_SERVICE_FROM, splitting off the display name into GRAFANA_SMTP_FROM_NAME.
+      GF_SMTP_FROM_ADDRESS: ${GRAFANA_SMTP_FROM_ADDRESS:-}
+      GF_SMTP_FROM_NAME: ${GRAFANA_SMTP_FROM_NAME:-Erudit Alerts}
+      GF_SMTP_STARTTLS_POLICY: MandatoryStartTLS
+      # The alert recipient(s), read by the provisioned contact point via $__env{SERVICE_EMAIL}.
+      SERVICE_EMAIL: ${SERVICE_EMAIL:-}
     volumes:
       - ${SCRABBLE_CONFIG_DIR:-.}/grafana/provisioning:/etc/grafana/provisioning:ro
       # Dashboards live under /etc/grafana (NOT /var/lib/grafana, which the
@@ -547,6 +585,24 @@ services:
           memory: 64M
     networks: [internal]
 
+  # blackbox_exporter lets Prometheus alert on TLS certificate expiry (a Caddy ACME
+  # renewal failure) via probe_ssl_earliest_cert_expiry. It probes the edge caddy that
+  # terminates TLS (prod: the published scrabble-caddy; the test contour has no compose
+  # caddy, so the probe simply finds no target and the cert metric is absent — the rule is
+  # absent-safe). See prometheus.yml and grafana alerting rules.
+  blackbox_exporter:
+    container_name: scrabble-blackbox-exporter
+    image: prom/blackbox-exporter:v0.25.0
+    restart: unless-stopped
+    logging: *default-logging
+    volumes:
+      - ${SCRABBLE_CONFIG_DIR:-.}/blackbox/blackbox.yml:/etc/blackbox_exporter/config.yml:ro
+    deploy:
+      resources:
+        limits:
+          memory: 64M
+    networks: [internal, edge]
+
 networks:
   internal:
     name: scrabble-internal

deploy/grafana/dashboards/users.json

@@ -56,6 +56,22 @@
       "gridPos": { "h": 8, "w": 24, "x": 0, "y": 24 },
       "datasource": { "type": "prometheus", "uid": "prometheus" },
       "targets": [{ "refId": "A", "expr": "sum(rate(local_eval_preview_total[1h])) by (path)", "legendFormat": "{{path}}" }]
+    },
+    {
+      "type": "timeseries",
+      "title": "Unsupported-engine screens (cumulative by reason)",
+      "description": "Clients turned away by the index.html boot guard because the engine cannot run the app (an old Android System WebView), by reason: no_bigint / no_proxy (a missing unpolyfillable primitive) or boot_error (an uncaught startup failure). Deduped per device/version, so this counts distinct blocked installs, not launches. The effective floor is Chrome 67 (BigInt).",
+      "gridPos": { "h": 8, "w": 12, "x": 0, "y": 32 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "targets": [{ "refId": "A", "expr": "sum(unsupported_engine_total) by (reason)", "legendFormat": "{{reason}}" }]
+    },
+    {
+      "type": "timeseries",
+      "title": "Unsupported engines by Chromium (rate)",
+      "description": "The same blocked clients by reported Chromium major version — which old in-app WebViews are still in the wild. \"other\" is an unparseable or out-of-range version.",
+      "gridPos": { "h": 8, "w": 12, "x": 12, "y": 32 },
+      "datasource": { "type": "prometheus", "uid": "prometheus" },
+      "targets": [{ "refId": "A", "expr": "sum(rate(unsupported_engine_total[1h])) by (chromium)", "legendFormat": "Chromium {{chromium}}" }]
     }
   ]
 }

deploy/grafana/provisioning/alerting/contactpoints.yaml

@@ -0,0 +1,13 @@
+# Grafana alerting contact point: the operator's alert mailbox, read from the
+# SERVICE_EMAIL container env (see docker-compose.yml grafana), so it stays per-contour.
+# SERVICE_EMAIL may hold several comma-separated addresses.
+apiVersion: 1
+contactPoints:
+  - orgId: 1
+    name: ops-email
+    receivers:
+      - uid: ops_email
+        type: email
+        settings:
+          addresses: $__env{SERVICE_EMAIL}
+          singleEmail: true

deploy/grafana/provisioning/alerting/policies.yaml

@@ -0,0 +1,10 @@
+# Notification policy: every alert routes to the operator email, grouped so a burst is one
+# message, with a 4-hour re-notify while still firing.
+apiVersion: 1
+policies:
+  - orgId: 1
+    receiver: ops-email
+    group_by: ['alertname']
+    group_wait: 30s
+    group_interval: 5m
+    repeat_interval: 4h

deploy/grafana/provisioning/alerting/rules.yaml

@@ -0,0 +1,214 @@
+# Grafana provisioned alert rules for the Scrabble contour. Each rule is a Prometheus
+# instant query (refId A) fed into a threshold expression (refId C). noDataState/execErrState
+# are OK so an absent metric never raises a false alert — notably cert-expiry, whose blackbox
+# probe has no target on the test contour (caddy is HTTP-only there). Metric names are the
+# real ones Prometheus exposes (edge_request_* from the gateway via the collector,
+# node_*/pg_*/probe_ssl_* from the exporters). All route to the ops-email contact point.
+apiVersion: 1
+groups:
+  - orgId: 1
+    name: scrabble-service
+    folder: Alerts
+    interval: 1m
+    rules:
+      - uid: svc_target_down
+        title: Scrape target down
+        condition: C
+        for: 3m
+        noDataState: OK
+        execErrState: OK
+        data:
+          - refId: A
+            relativeTimeRange: { from: 300, to: 0 }
+            datasourceUid: prometheus
+            model: { refId: A, expr: up, instant: true }
+          - refId: C
+            datasourceUid: __expr__
+            model:
+              refId: C
+              type: threshold
+              expression: A
+              conditions:
+                - evaluator: { type: lt, params: [1] }
+        labels: { severity: critical }
+        annotations: { summary: 'A Prometheus scrape target is down (up < 1).' }
+
+      - uid: edge_error_rate
+        title: Gateway internal-error rate high
+        condition: C
+        for: 10m
+        noDataState: OK
+        execErrState: OK
+        data:
+          - refId: A
+            relativeTimeRange: { from: 600, to: 0 }
+            datasourceUid: prometheus
+            model:
+              refId: A
+              expr: sum by (service_name) (rate(edge_request_duration_count{result="internal"}[5m]))
+              instant: true
+          - refId: C
+            datasourceUid: __expr__
+            model:
+              refId: C
+              type: threshold
+              expression: A
+              conditions:
+                - evaluator: { type: gt, params: [0.05] }
+        labels: { severity: warning }
+        annotations: { summary: 'Sustained internal (5xx-equivalent) errors at the edge.' }
+
+      - uid: edge_latency_p99
+        title: Gateway request latency p99 high
+        condition: C
+        for: 10m
+        noDataState: OK
+        execErrState: OK
+        data:
+          - refId: A
+            relativeTimeRange: { from: 600, to: 0 }
+            datasourceUid: prometheus
+            model:
+              refId: A
+              expr: histogram_quantile(0.99, sum by (le, service_name) (rate(edge_request_duration_bucket[5m])))
+              instant: true
+          - refId: C
+            datasourceUid: __expr__
+            model:
+              refId: C
+              type: threshold
+              expression: A
+              conditions:
+                - evaluator: { type: gt, params: [1] }
+        labels: { severity: warning }
+        annotations: { summary: 'Edge request p99 latency above 1s.' }
+
+      - uid: tls_cert_expiry
+        title: TLS certificate nearing expiry
+        condition: C
+        for: 15m
+        noDataState: OK
+        execErrState: OK
+        data:
+          - refId: A
+            relativeTimeRange: { from: 300, to: 0 }
+            datasourceUid: prometheus
+            model:
+              refId: A
+              expr: (probe_ssl_earliest_cert_expiry - time()) / 86400
+              instant: true
+          - refId: C
+            datasourceUid: __expr__
+            model:
+              refId: C
+              type: threshold
+              expression: A
+              conditions:
+                - evaluator: { type: lt, params: [20] }
+        labels: { severity: critical }
+        annotations: { summary: 'Edge TLS cert has under 20 days left — Caddy ACME renewal may have failed.' }
+
+  - orgId: 1
+    name: scrabble-host
+    folder: Alerts
+    interval: 1m
+    rules:
+      - uid: host_mem_low
+        title: Host memory low
+        condition: C
+        for: 5m
+        noDataState: OK
+        execErrState: OK
+        data:
+          - refId: A
+            relativeTimeRange: { from: 300, to: 0 }
+            datasourceUid: prometheus
+            model:
+              refId: A
+              expr: node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes
+              instant: true
+          - refId: C
+            datasourceUid: __expr__
+            model:
+              refId: C
+              type: threshold
+              expression: A
+              conditions:
+                - evaluator: { type: lt, params: [0.1] }
+        labels: { severity: critical }
+        annotations: { summary: 'Under 10% host memory available.' }
+
+      - uid: host_disk_low
+        title: Host disk low
+        condition: C
+        for: 10m
+        noDataState: OK
+        execErrState: OK
+        data:
+          - refId: A
+            relativeTimeRange: { from: 300, to: 0 }
+            datasourceUid: prometheus
+            model:
+              refId: A
+              expr: min(node_filesystem_avail_bytes / node_filesystem_size_bytes)
+              instant: true
+          - refId: C
+            datasourceUid: __expr__
+            model:
+              refId: C
+              type: threshold
+              expression: A
+              conditions:
+                - evaluator: { type: lt, params: [0.1] }
+        labels: { severity: critical }
+        annotations: { summary: 'A host filesystem is under 10% free.' }
+
+      - uid: host_cpu_high
+        title: Host CPU saturated
+        condition: C
+        for: 10m
+        noDataState: OK
+        execErrState: OK
+        data:
+          - refId: A
+            relativeTimeRange: { from: 600, to: 0 }
+            datasourceUid: prometheus
+            model:
+              refId: A
+              expr: 1 - avg(rate(node_cpu_seconds_total{mode="idle"}[5m]))
+              instant: true
+          - refId: C
+            datasourceUid: __expr__
+            model:
+              refId: C
+              type: threshold
+              expression: A
+              conditions:
+                - evaluator: { type: gt, params: [0.9] }
+        labels: { severity: warning }
+        annotations: { summary: 'Host CPU above 90% for 10 minutes.' }
+
+      - uid: pg_connections_high
+        title: Postgres connections high
+        condition: C
+        for: 5m
+        noDataState: OK
+        execErrState: OK
+        data:
+          - refId: A
+            relativeTimeRange: { from: 300, to: 0 }
+            datasourceUid: prometheus
+            model:
+              refId: A
+              expr: sum(pg_stat_activity_count) / max(pg_settings_max_connections)
+              instant: true
+          - refId: C
+            datasourceUid: __expr__
+            model:
+              refId: C
+              type: threshold
+              expression: A
+              conditions:
+                - evaluator: { type: gt, params: [0.8] }
+        labels: { severity: warning }
+        annotations: { summary: 'Postgres using over 80% of max_connections.' }

deploy/prod-deploy.sh

@@ -42,6 +42,15 @@ PREV_STATE_FILE="${PREV_STATE_FILE:-/opt/scrabble/PREVIOUS_TAG}"
 PG_USER="${POSTGRES_USER:-scrabble}"
 PG_DB="${POSTGRES_DB:-scrabble}"
 
+# Edge maintenance page. caddy serves a static 503 "works in progress" page for the
+# user-facing routes while this flag file exists (deploy/caddy/Caddyfile). We hold it
+# across the roll / migration window and clear it on ANY exit — success, a health
+# failure + rollback, or an unexpected error — via the trap, so users get a graceful
+# page instead of raw mid-swap 502s and the flag can never get stuck on.
+MAINT_FLAG="${MAINT_FLAG:-${SCRABBLE_CONFIG_DIR:-/opt/scrabble}/caddy/on}"
+maint_off() { rm -f "$MAINT_FLAG" 2>/dev/null || true; }
+trap maint_off EXIT
+
 cd "$COMPOSE_DIR" || { echo "compose dir $COMPOSE_DIR missing"; exit 1; }
 export REGISTRY
 # otelcol joins the host docker group to read the socket; the GID varies per host.
@@ -119,6 +128,13 @@ if [ -z "$(docker ps -aq -f name=scrabble-backend)" ]; then
   exit 0
 fi
 
+# Existing stack: raise the maintenance page for the whole roll (and any migration
+# window). It shows once caddy carries the gate (from this feature's own deploy
+# onward); the EXIT trap lowers it however this run ends.
+mkdir -p "$(dirname "$MAINT_FLAG")"
+: > "$MAINT_FLAG"
+echo "maintenance page raised ($MAINT_FLAG)"
+
 # Migration deploy: freeze writes and snapshot a consistent dump before migrating.
 if [ "$MIGRATION" = 1 ]; then
   echo "migration deploy: opening maintenance window (stopping the backend = the only writer)"

deploy/prometheus/prometheus.yml

@@ -23,3 +23,21 @@ scrape_configs:
   - job_name: node
     static_configs:
       - targets: ["node_exporter:9100"]
+  # TLS certificate expiry of the edge caddy (probe_ssl_earliest_cert_expiry), for the
+  # certificate-renewal-failure alert. Effective on prod, where caddy terminates TLS on
+  # :443; on the test contour caddy is HTTP-only, so the probe finds nothing and the metric
+  # is absent (the alert rule is absent-safe). The exporter probes the target passed as a
+  # scrape parameter and answers on its own :9115.
+  - job_name: blackbox_tls
+    metrics_path: /probe
+    params:
+      module: [tls_cert]
+    static_configs:
+      - targets: ["caddy:443"]
+    relabel_configs:
+      - source_labels: [__address__]
+        target_label: __param_target
+      - source_labels: [__param_target]
+        target_label: instance
+      - target_label: __address__
+        replacement: blackbox_exporter:9115

deploy/write-prod-bot-env.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+# Render the prod bot-host env.bot.sh from the workflow job environment.
+#
+# Sourced identically by prod-deploy (deploy-bot) and prod-rollback
+# (rollback-bot) so the two paths cannot drift (see deploy/write-prod-env.sh
+# for the same rationale on the main host).
+#
+# Usage:  BOT_IMAGE=<image ref> bash deploy/write-prod-bot-env.sh <out-path>
+#
+# Every other value comes from the caller's environment (the job `env:` block).
+out="${1:?usage: write-prod-bot-env.sh <out-path>}"
+
+# The bot's Mini App URL is the same public origin the SPA serves; derive it
+# rather than storing a second copy.
+base="${PUBLIC_BASE_URL%/}"
+TELEGRAM_MINIAPP_URL="$base/telegram/"
+
+cat > "$out" <<EOF
+export SCRABBLE_CONFIG_DIR='/opt/scrabble'
+export BOT_IMAGE='$BOT_IMAGE'
+export BOTLINK_GATEWAY_ADDR='$MAIN_HOST:9443'
+export TELEGRAM_BOT_TOKEN='$TELEGRAM_BOT_TOKEN'
+export TELEGRAM_MINIAPP_URL='$TELEGRAM_MINIAPP_URL'
+export TELEGRAM_GAME_CHANNEL_ID='$TELEGRAM_GAME_CHANNEL_ID'
+export TELEGRAM_CHAT_ID='$TELEGRAM_CHAT_ID'
+export TELEGRAM_SUPPORT_CHAT_ID='$TELEGRAM_SUPPORT_CHAT_ID'
+export TELEGRAM_PROMO_BOT_TOKEN='$TELEGRAM_PROMO_BOT_TOKEN'
+export TELEGRAM_BOT_USERNAME='$TELEGRAM_BOT_USERNAME'
+export TELEGRAM_BOT_LINK='$TELEGRAM_BOT_LINK'
+export LOG_LEVEL='${LOG_LEVEL:-info}'
+EOF

deploy/write-prod-env.sh

@@ -0,0 +1,76 @@
+#!/usr/bin/env bash
+# Render the prod main-host runtime env.sh from the workflow job environment.
+#
+# Sourced identically by prod-deploy (deploy-main) and prod-rollback
+# (rollback-main) so the two paths cannot drift: a rollback recreates the
+# containers, so it must re-render the SAME runtime env a full deploy does —
+# otherwise transactional email, VK login and Grafana alerts silently go dark
+# after a rollback until the next full deploy.
+#
+# Usage:  APP_VERSION=<tag> bash deploy/write-prod-env.sh <out-path>
+#
+# Every other value comes from the caller's environment (the job `env:` block,
+# vars.* / secrets.*). Mirrors the compose interpolation contract in
+# deploy/.env.example; keep in sync with deploy/docker-compose{,.prod}.yml.
+out="${1:?usage: write-prod-env.sh <out-path>}"
+
+# Derive the public URLs from the one canonical origin instead of storing each
+# under its own variable. The path suffixes are structural (SPA routes / the
+# Caddy /_gm sub-path), identical on every contour.
+base="${PUBLIC_BASE_URL%/}"
+TELEGRAM_MINIAPP_URL="$base/telegram/"
+GRAFANA_ROOT_URL="$base/_gm/grafana/"
+VITE_VK_ID_REDIRECT_URL="$base/app/"
+
+# Grafana needs a BARE from-address (it rejects the "Name" <addr> form the backend
+# go-mail accepts, and validates it even when SMTP is disabled — a bad value
+# crash-loops Grafana). Split the display-format SERVICE From into address + name;
+# the backend keeps the full form.
+svc_from="${SMTP_RELAY_SERVICE_FROM:-}"
+GRAFANA_SMTP_FROM_NAME=''
+case "$svc_from" in
+  *"<"*">"*)
+    GRAFANA_SMTP_FROM_ADDRESS="$(printf '%s' "$svc_from" | sed -E 's/.*<([^>]+)>.*/\1/')"
+    GRAFANA_SMTP_FROM_NAME="$(printf '%s' "$svc_from" | sed -E 's/[[:space:]]*<[^>]*>.*$//; s/^"//; s/"$//')" ;;
+  *) GRAFANA_SMTP_FROM_ADDRESS="$svc_from" ;;
+esac
+
+cat > "$out" <<EOF
+export REGISTRY='$REGISTRY'
+export SCRABBLE_CONFIG_DIR='/opt/scrabble'
+export POSTGRES_DB='${POSTGRES_DB:-scrabble}'
+export POSTGRES_USER='${POSTGRES_USER:-scrabble}'
+export POSTGRES_PASSWORD='$POSTGRES_PASSWORD'
+export GM_BASICAUTH_USER='${GM_BASICAUTH_USER:-gm}'
+export GM_BASICAUTH_HASH='$GM_BASICAUTH_HASH'
+export GRAFANA_ADMIN_PASSWORD='$GRAFANA_ADMIN_PASSWORD'
+export GRAFANA_ROOT_URL='$GRAFANA_ROOT_URL'
+export CADDY_SITE_ADDRESS='$CADDY_SITE_ADDRESS'
+export LOG_LEVEL='${LOG_LEVEL:-info}'
+export DICT_VERSION='$DICT_VERSION'
+export APP_VERSION='$APP_VERSION'
+export TELEGRAM_BOT_TOKEN='$TELEGRAM_BOT_TOKEN'
+export TELEGRAM_MINIAPP_URL='$TELEGRAM_MINIAPP_URL'
+export GATEWAY_VK_APP_SECRET='$GATEWAY_VK_APP_SECRET'
+export VITE_VK_APP_ID='$VITE_VK_APP_ID'
+export VITE_VK_ID_REDIRECT_URL='$VITE_VK_ID_REDIRECT_URL'
+export GATEWAY_VK_ID_CLIENT_SECRET='$GATEWAY_VK_ID_CLIENT_SECRET'
+export EXPORT_SIGN_KEY='$EXPORT_SIGN_KEY'
+export SMTP_RELAY_HOST='$SMTP_RELAY_HOST'
+export SMTP_RELAY_PORT='$SMTP_RELAY_PORT'
+export SMTP_RELAY_TLS='$SMTP_RELAY_TLS'
+export SMTP_RELAY_USER='$SMTP_RELAY_USER'
+export SMTP_RELAY_PASS='$SMTP_RELAY_PASS'
+export SMTP_RELAY_FROM='$SMTP_RELAY_FROM'
+export SMTP_RELAY_ADMIN_FROM='$SMTP_RELAY_ADMIN_FROM'
+export ADMIN_EMAIL='$ADMIN_EMAIL'
+export SMTP_RELAY_SERVICE_FROM='$SMTP_RELAY_SERVICE_FROM'
+export GRAFANA_SMTP_FROM_ADDRESS='$GRAFANA_SMTP_FROM_ADDRESS'
+export GRAFANA_SMTP_FROM_NAME='$GRAFANA_SMTP_FROM_NAME'
+export SERVICE_EMAIL='$SERVICE_EMAIL'
+export GRAFANA_SMTP_PORT='$GRAFANA_SMTP_PORT'
+export GF_SMTP_ENABLED='$GF_SMTP_ENABLED'
+export PUBLIC_BASE_URL='$PUBLIC_BASE_URL'
+export GATEWAY_HONEYTOKEN='$GATEWAY_HONEYTOKEN'
+export GATEWAY_ABUSE_BAN_ENABLED='true'
+EOF

docs/ARCHITECTURE.md

@@ -243,8 +243,8 @@ arrive from a platform rather than completing a mandatory registration).
   also carries a **one-tap confirm deeplink** (`/app/#/confirm/<token>`, an opaque
   256-bit token stored only as its SHA-256, 12-hour TTL): a login mints a session in the
   browser that opens it (magic-link), a link confirms the identity and emits a `notify`
-  profile-refresh to the in-app session, and a would-be merge is deferred to the
-  interactive flow. The confirm runs on load; the token rides the URL fragment (never
+  profile-refresh to the in-app session, a change switches the account's email in place,
+  and a would-be merge is deferred to the interactive flow. The confirm runs on load; the token rides the URL fragment (never
   sent to the server), so a plain link prefetch cannot reach it, and the manual
   six-digit code is the fallback if an aggressive scanner runs the page. An
   **email-login** account is created flagged `is_guest` and stays reapable until the
@@ -257,12 +257,52 @@ arrive from a platform rather than completing a mandatory registration).
   control of the identity before attaching it: **email** through the confirm-code
   flow, **Telegram** through the web **Login Widget** (validated by the validator,
   HMAC under `SHA-256(bot_token)` — distinct from Mini App initData; the gateway
-  passes the trusted `external_id` to the backend, as for `auth.telegram`). The
+  passes the trusted `external_id` to the backend, as for `auth.telegram`), and **VK**
+  through **VK ID web login** (`gateway/internal/vkid`): the browser runs the VK ID raw
+  OAuth 2.1 flow with PKCE — a full-page redirect to VK's hosted login, no `@vkid/sdk` —
+  and the gateway completes the **confidential code exchange** server-side under the VK
+  "Web" app's protected key (a distinct VK app from the Mini App) to obtain the trusted
+  `external_id`. A browser has no signed launch parameters, so unlike the VK Mini App
+  (offline HMAC, §12) this makes an outbound call to `id.vk.com`, and it is web-only — a
+  full-page redirect would strand a native Mini App webview. The
   request step **always** sends/accepts the proof (no pre-send "already taken"
   signal, so a probe cannot enumerate registered addresses); a required **merge**
   is revealed **only after** the proof is verified and is performed behind an
-  explicit, irreversible confirmation. A free identity is simply attached (and a
+  explicit, irreversible confirmation (for VK, whose authorization code is single-use,
+  the merge re-authorizes for a fresh code). A free identity is simply attached (and a
   guest is promoted to durable, clearing `is_guest`).
+- **Unlink** detaches a platform identity (`telegram`/`vk`) from the profile. The
+  backend **refuses removing the last identity** (`ErrLastIdentity`), so an account
+  never becomes unreachable; the UI mirrors the guard by hiding Unlink when only one
+  method remains. **Email is never unlinked — it is changed.**
+- **Change email** mails a confirm-code (`purpose=change`) to the new address on the
+  authenticated account and, on confirm (code or one-tap deeplink), **atomically
+  replaces** the account's email identity with the new one, freeing the old address. A
+  new address already confirmed by **another** account is refused **without disclosure**
+  (a neutral "check the address or contact support") and **never merged** — the anti-
+  enumeration check is only reachable by someone who controls the new mailbox.
+- **Deletion is legal retention, not erasure** (`internal/accountdelete`). The account row
+  survives as a **tombstone** (`accounts.deleted_at`) — its chat/complaint foreign keys
+  have no cascade, so a hard delete is impossible. `AnonymizeAndTombstone` **journals**
+  every live identity into an append-only **`retained_identities`** log (the legal dossier)
+  then removes it, freeing the `(kind, external_id)` for a new account to reuse; it scrubs
+  the live `display_name` → **`[Deleted]`** (an unspoofable sentinel — the editable-name
+  rule forbids brackets) while snapshotting the real name into `deleted_display_name`,
+  anonymises the game-seat snapshots, and drops the account's own friendships / blocks /
+  invitations / friend-codes / drafts / pending-codes. **Chat, feedback and complaints are
+  kept.** The orchestration a layer up resigns the account's active games (so opponents are
+  not stranded), **drops its all-robot games** (no human opponent; children cascade), and
+  revokes its sessions. Every credential detachment — **unlink, email change, delete and a
+  merge collision** — writes a `retained_identities` row (`reason`), so the dossier keeps the
+  full timeline. (A merge that would otherwise leave the survivor with two identities of one
+  kind — e.g. each account held a confirmed email — keeps the primary's and journals the
+  secondary's with `reason=merge` before dropping it.)
+  Step-up is a mailed code (`purpose=delete`, no deeplink — a stray click must not delete;
+  `ConfirmByToken` refuses a delete token) for an email account, else a typed phrase.
+  `last_login_at` / `last_login_ip` are stamped on the cold-load profile fetch (throttled
+  to once an hour). A **two-year TTL reaper** (from the event) purges the whole dossier —
+  the journal, plus a deleted account's feedback thread and dossier PII — while the chat and
+  the tombstone row stay.
 - **Merge** retires the account that owns the linked identity into the **current**
   account, in a single transaction (`internal/accountmerge`): statistics summed
   (counters incl. moves/hints added, max points kept, and the per-variant best moves
@@ -974,6 +1014,19 @@ browser), so an open in-app session reflects it at once.
   both are surfaced on the **Scrabble — Resources** Grafana dashboard, which captures the
   stress-run resource profile. (`docker_stats` replaced cAdvisor, which on the contour
   host resolved only the root cgroup — a separate-XFS `/var/lib/docker`.)
+- **Alerting.** Grafana emails infra alerts through the shared relay (its own SMTP on the
+  STARTTLS port) to `SERVICE_EMAIL`, from provisioned rules
+  (`deploy/grafana/provisioning/alerting/`): a scrape-target down, the gateway's
+  internal-error rate and p99 latency (`edge_request_*`), host memory/disk/CPU
+  (node_exporter), Postgres connection saturation (postgres_exporter), and **TLS certificate
+  expiry < 20 days** — a Caddy ACME-renewal-failure signal from a **`blackbox_exporter`**
+  probe of the edge caddy (`probe_ssl_earliest_cert_expiry`). Every rule is `noDataState=OK`,
+  so an absent metric never false-alerts — notably the cert probe, which has no TLS target on
+  the HTTP-only contour caddy. Separately, the backend's **admin-alert worker**
+  (`internal/adminalert`, started from `main`) emails the operator (`ADMIN_EMAIL`, from a
+  distinct `SMTP_RELAY_ADMIN_FROM`) when new player feedback or word complaints arrive,
+  **coalescing** a burst into one digest per interval; both recipients may be several
+  comma-separated addresses. Both paths are inert unless configured.
 - Per-request server-side timing via gin middleware from day one (the access log
   carries method, route, status, latency and the active trace id). A
   client-measured RTT piggybacked on the next request is a later enhancement.
@@ -1017,6 +1070,17 @@ browser), so an open in-app session reflects it at once.
   it fills IndexedDB — and is surfaced on the **Scrabble — Users** dashboard. Lossy by
   design (a dropped beacon just retries its batch on the next flush); it is telemetry, never
   a game input.
+- **Unsupported-engine screens (client-reported):** the ES5 boot guard in `index.html` (§13)
+  shows a full-screen "your device's OS or browser can't run the app" screen — instead of a white
+  screen — when the engine lacks an unpolyfillable essential (`BigInt`, the 64-bit FlatBuffers
+  decode; or `Proxy`, Svelte 5 runes) or an uncaught error aborts boot; the effective floor is
+  Chrome 67. It then fires one fire-and-forget beacon (`POST /telemetry/unsupported` —
+  unauthenticated, since the client never booted, but per-IP public-limited and body-capped),
+  deduped in `localStorage` by app version + reason + Chromium so a user reopening the app is one
+  report. The gateway folds it into `unsupported_engine_total` (`reason` =
+  no_bigint/no_proxy/boot_error/other; `chromium` = the major version reduced to a bounded range so
+  a spoofed beacon cannot inflate cardinality) and logs the full user agent (not a label). Surfaced
+  on the **Scrabble — Users** dashboard beside app opens.
 - **Rate-limit observability:** every limiter rejection increments the gateway
   counter `gateway_rate_limited_total` (`class` = user/public/email/admin — aggregate
   only, honouring the no-per-user-label discipline above) and logs one **Debug** line;

docs/FUNCTIONAL.md

@@ -96,10 +96,6 @@ reconnect), and pending reads resume on their own — the interface stays usable
 flashing a red banner each time.
 
 ### Accounts, linking & merge
-_Sign-in is currently provider-only, so the in-profile linking UI is temporarily hidden; it
-returns once the anonymous `/app/` guest (whose upgrade path this is) ships. The flow below
-describes it for when it does._
-
 First platform contact auto-provisions a durable account. From the profile a player
 links an email (via a confirm code) or their Telegram (via the web sign-in); a guest
 who links their first identity becomes a durable account. The "already taken" status
@@ -111,6 +107,28 @@ when a guest links an identity that already has a durable account, where the dur
 account is kept and the guest's games move into it. A merge is blocked only while the
 two accounts share a game still in progress.
 
+The profile lists the account's **sign-in methods**. On the web a player can add
+Telegram (a login-widget popup) or VK (VK ID web login — a redirect to VK's sign-in and
+back); inside a Mini App the host platform is already linked. Linking a provider that
+already belongs to another account offers the same irreversible **merge** as email
+linking. A linked provider can be **unlinked** — except the last
+remaining sign-in method, which is refused so the account stays reachable. **Email is
+never unlinked; it is changed**: the player enters a new address, confirms a code
+mailed to it, and the account switches to it atomically, freeing the old address. A new
+address that already belongs to another account is refused with a neutral "check the
+address or contact support" — the switch never merges and never reveals the other
+account.
+
+A player can **delete their account**. This is a legal-retention removal, not an erasure:
+the account is deactivated and its live surfaces anonymised (opponents see "[Deleted]"), its
+sign-in methods are freed for reuse, and its sessions are revoked — but a dossier (the
+credentials that were linked, the last login, and the player's messages) is retained for
+the operator and purged after two years. Confirming deletion needs a mailed code for an
+account with an email, or a typed phrase otherwise. Active games are forfeited so opponents
+are not stranded; solo games against the AI are removed, while games with a human opponent
+are kept under the anonymised name and the player's chat stays. Reopening the app after
+deletion simply creates a fresh account.
+
 ### Lobby & matchmaking
 On a cold open the lobby greets the player with a brief **loading splash** — Scrabble tiles
 spelling **ЭРУДИТ / ЗАГРУЗКА / ОЖИДАНИЕ** as a small crossword — that clears the moment the

docs/FUNCTIONAL_ru.md

@@ -100,10 +100,6 @@ Telegram держит **единого бота**: все игроки поль
 рабочим вместо красного баннера каждый раз.
 
 ### Аккаунты, привязка и слияние
-_Вход сейчас только через провайдера, поэтому UI привязки в профиле временно скрыт; он
-вернётся, когда появится анонимный `/app/`-гость (для апгрейда которого он и нужен). Описание
-ниже — на этот случай._
-
 Первый контакт с платформы заводит постоянный аккаунт. Из профиля игрок
 привязывает email (по confirm-коду) или свой Telegram (через веб-вход); гость,
 привязавший первую личность, становится постоянным аккаунтом. Факт «личность уже
@@ -115,6 +111,27 @@ _Вход сейчас только через провайдера, поэто
 тогда сохраняется постоянный аккаунт, а игры гостя переходят в него. Слияние
 запрещено, только пока у аккаунтов есть общая незавершённая игра.
 
+В профиле перечислены **способы входа** аккаунта. В вебе игрок может добавить
+Telegram (попап логин-виджета) или VK (веб-вход VK ID — редирект на страницу входа VK и
+обратно); внутри Mini App платформа-хозяин уже привязана. Привязка провайдера, уже
+принадлежащего другому аккаунту, предлагает то же необратимое **слияние**, что и привязка
+email. Привязанного провайдера можно **отвязать** — кроме последнего
+оставшегося способа входа: он не отвязывается, чтобы аккаунт оставался достижимым.
+**Email не отвязывают — его меняют**: игрок вводит новый адрес, подтверждает код,
+отправленный на него, и аккаунт атомарно переключается на новый адрес, освобождая
+старый. Новый адрес, уже принадлежащий другому аккаунту, отклоняется нейтральным
+«проверьте правильность e-mail или обратитесь в поддержку» — смена никогда не сливает
+аккаунты и не раскрывает чужой.
+
+Игрок может **удалить аккаунт**. Это удаление с юридическим удержанием, а не стирание:
+аккаунт деактивируется, живые поверхности обезличиваются (соперники видят «[Deleted]»),
+способы входа освобождаются под повторную регистрацию, сессии отзываются — но досье
+(какие креды были привязаны, последний вход, сообщения игрока) сохраняется для оператора и
+чистится через два года. Подтверждение удаления — код на почту (если у аккаунта есть
+e-mail) либо ввод фразы. Активные игры форфейтятся, чтобы не бросать соперников; одиночные
+игры против ИИ удаляются, а игры с людьми сохраняются под обезличенным именем, чат игрока
+остаётся. Если снова открыть приложение после удаления — создаётся новый аккаунт.
+
 ### Лобби и подбор
 При холодном запуске лобби встречает игрока короткой **заставкой загрузки** — фишки Scrabble
 складывают небольшой кроссворд из слов **ЭРУДИТ / ЗАГРУЗКА / ОЖИДАНИЕ** — и она исчезает, как

gateway/Dockerfile

@@ -25,12 +25,16 @@ ARG VITE_TELEGRAM_BOT_ID=
 ARG VITE_TELEGRAM_LINK=
 ARG VITE_TELEGRAM_GAME_CHANNEL_NAME=
 ARG VITE_VK_APP_LINK=
+ARG VITE_VK_APP_ID=
+ARG VITE_VK_ID_REDIRECT_URL=
 ARG VITE_GATEWAY_URL=
 ARG VITE_APP_VERSION=
 ENV VITE_TELEGRAM_BOT_ID=$VITE_TELEGRAM_BOT_ID \
     VITE_TELEGRAM_LINK=$VITE_TELEGRAM_LINK \
     VITE_TELEGRAM_GAME_CHANNEL_NAME=$VITE_TELEGRAM_GAME_CHANNEL_NAME \
     VITE_VK_APP_LINK=$VITE_VK_APP_LINK \
+    VITE_VK_APP_ID=$VITE_VK_APP_ID \
+    VITE_VK_ID_REDIRECT_URL=$VITE_VK_ID_REDIRECT_URL \
     VITE_GATEWAY_URL=$VITE_GATEWAY_URL \
     VITE_APP_VERSION=$VITE_APP_VERSION
 

gateway/README.md

@@ -61,6 +61,12 @@ round-trip, then forwards the trusted `vk_user_id` (and the client-read display
 from the signed params) to the backend. When `GATEWAY_VK_APP_SECRET` is unset VK auth is disabled
 (`auth.vk` is unregistered).
 
+`link.vk.confirm`/`merge` link a VK identity from a **browser** (not a Mini App) via **VK ID web
+login** (`internal/vkid`): the SPA runs the VK ID raw OAuth 2.1 flow (PKCE, no `@vkid/sdk`) and
+the gateway completes the **confidential code exchange** at `id.vk.com` under a SEPARATE VK "Web"
+app's protected key — the only op here that calls VK (the Mini App path above is offline). All
+three `GATEWAY_VK_ID_*` unset leaves the ops unregistered.
+
 The message-type catalog: `auth.telegram`, `auth.vk`, `auth.guest`,
 `auth.email.request`, `auth.email.login`, `profile.get`, `game.submit_play`,
 `game.state`, `lobby.enqueue`, `lobby.poll`, `chat.post`, `chat.read` and the play-loop ops;
@@ -72,9 +78,10 @@ refetch). The social/account/history ops —
 `blocks.*`, `invitation.*` (list/create/accept/decline/cancel), `profile.update`,
 `stats.get`, `game.gcg`, and the `notify` live event — go through the identical
 transcode pattern (`transcode_social.go`). Account linking & merge
-— `link.email.request/confirm/merge` and `link.telegram.confirm/merge`
-(`transcode_link.go`); the telegram ops validate the **Login Widget** payload via the
-validator (`ValidateLoginWidget`) and forward the trusted `external_id`. These
+— `link.email.request/confirm/merge`, `link.telegram.confirm/merge` and
+`link.vk.confirm/merge` (`transcode_link.go`); the telegram ops validate the **Login
+Widget** payload via the validator (`ValidateLoginWidget`), the vk ops complete the VK ID
+web code exchange via `internal/vkid`, and both forward the trusted `external_id`. These
 **superseded** the former `email.bind.*` ops, which were removed.
 
 ## Configuration
@@ -89,6 +96,7 @@ validator (`ValidateLoginWidget`) and forward the trusted `external_id`. These
 | `GATEWAY_ADMIN_USER` / `GATEWAY_ADMIN_PASSWORD` | unset | enable + guard the admin console at `/_gm` |
 | `GATEWAY_VALIDATOR_ADDR` | unset | Telegram validator gRPC address (enables initData / Login Widget validation) |
 | `GATEWAY_VK_APP_SECRET` | unset | VK app protected key; enables in-process VK Mini App launch-signature verification (`auth.vk`) |
+| `GATEWAY_VK_ID_APP_ID` / `GATEWAY_VK_ID_CLIENT_SECRET` / `GATEWAY_VK_ID_REDIRECT_URL` | unset | VK ID "Web" app credentials for VK web-login linking (`link.vk.*`): the server-side confidential OAuth 2.1 code exchange. A separate VK app from `GATEWAY_VK_APP_SECRET`; all three required to enable the ops |
 | `GATEWAY_BOTLINK_ADDR` | unset | reverse mTLS bot-link listener the remote bot dials (enables out-of-app push + admin relay) |
 | `GATEWAY_BOTLINK_RELAY_ADDR` | unset | plaintext internal listener serving the backend admin `SendToUser`/`SendToGameChannel` relay |
 | `GATEWAY_BOTLINK_TLS_CERT` / `_KEY` / `_CA` | unset | gateway server cert, its key, and the CA that signs accepted bot client certs (required when `GATEWAY_BOTLINK_ADDR` is set) |

gateway/cmd/gateway/main.go

@@ -33,6 +33,7 @@ import (
 	"scrabble/gateway/internal/ratelimit"
 	"scrabble/gateway/internal/session"
 	"scrabble/gateway/internal/transcode"
+	"scrabble/gateway/internal/vkid"
 	"scrabble/pkg/mtls"
 	botlinkv1 "scrabble/pkg/proto/botlink/v1"
 	telegramv1 "scrabble/pkg/proto/telegram/v1"
@@ -190,7 +191,15 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 		logger.Info("admin console disabled (set GATEWAY_ADMIN_USER and GATEWAY_ADMIN_PASSWORD)")
 	}
 
-	registry := transcode.NewRegistry(backend, validator, transcode.WithVKAuth(cfg.VKAppSecret))
+	// VK ID web login (browser VK-identity linking) is optional: build the confidential
+	// code-exchanger only when fully configured, else leave the interface nil so the
+	// link.vk.* ops stay unregistered.
+	var vkidExchanger transcode.VKIDExchanger
+	if cfg.VKID.Enabled() {
+		vkidExchanger = vkid.New(cfg.VKID.AppID, cfg.VKID.ClientSecret, cfg.VKID.RedirectURI)
+		logger.Info("vk id web login enabled")
+	}
+	registry := transcode.NewRegistry(backend, validator, transcode.WithVKAuth(cfg.VKAppSecret), transcode.WithVKLink(vkidExchanger))
 	edge := connectsrv.NewServer(connectsrv.Deps{
 		Registry:     registry,
 		Sessions:     sessions,

gateway/internal/backendclient/api.go

@@ -37,6 +37,11 @@ type ProfileResp struct {
 	// Banner is the advertising-banner block, present only for a viewer eligible to
 	// see the banner. The gateway forwards it verbatim into the Profile payload.
 	Banner *BannerResp `json:"banner,omitempty"`
+	// Email is the confirmed email ("" when none); TelegramLinked/VkLinked report an
+	// attached platform identity — they drive the profile's link/unlink/change controls.
+	Email          string `json:"email"`
+	TelegramLinked bool   `json:"telegram_linked"`
+	VkLinked       bool   `json:"vk_linked"`
 }
 
 // BannerResp is the advertising-banner block of an eligible viewer's profile: the

gateway/internal/backendclient/api_social.go

@@ -335,6 +335,69 @@ func (c *Client) LinkTelegramMerge(ctx context.Context, userID, externalID strin
 	return out, err
 }
 
+// LinkVK attaches a gateway-validated VK identity to the caller or reports a required
+// merge. externalID is the trusted vk user id resolved from the VK ID code exchange.
+func (c *Client) LinkVK(ctx context.Context, userID, externalID string) (LinkResultResp, error) {
+	var out LinkResultResp
+	err := c.do(ctx, http.MethodPost, "/api/v1/user/link/vk", userID, "",
+		map[string]string{"external_id": externalID}, &out)
+	return out, err
+}
+
+// LinkVKMerge merges the account owning a gateway-validated VK identity into the
+// caller's.
+func (c *Client) LinkVKMerge(ctx context.Context, userID, externalID string) (LinkResultResp, error) {
+	var out LinkResultResp
+	err := c.do(ctx, http.MethodPost, "/api/v1/user/link/vk/merge", userID, "",
+		map[string]string{"external_id": externalID}, &out)
+	return out, err
+}
+
+// ChangeEmailRequest asks the backend to mail a confirm-code to a new address for an
+// authenticated email change.
+func (c *Client) ChangeEmailRequest(ctx context.Context, userID, email string) error {
+	return c.do(ctx, http.MethodPost, "/api/v1/user/link/email/change/request", userID, "",
+		map[string]string{"email": email}, nil)
+}
+
+// ChangeEmailConfirm verifies the code and atomically switches the account's email,
+// returning the refreshed profile in the result.
+func (c *Client) ChangeEmailConfirm(ctx context.Context, userID, email, code string) (LinkResultResp, error) {
+	var out LinkResultResp
+	err := c.do(ctx, http.MethodPost, "/api/v1/user/link/email/change/confirm", userID, "",
+		map[string]string{"email": email, "code": code}, &out)
+	return out, err
+}
+
+// DeleteRequestResp reports which account-deletion step-up the account uses.
+type DeleteRequestResp struct {
+	Method string `json:"method"`
+}
+
+// DeleteRequest starts account deletion: the backend mails a delete code (email accounts)
+// or reports the typed-phrase path.
+func (c *Client) DeleteRequest(ctx context.Context, userID string) (DeleteRequestResp, error) {
+	var out DeleteRequestResp
+	err := c.do(ctx, http.MethodPost, "/api/v1/user/delete/request", userID, "", nil, &out)
+	return out, err
+}
+
+// DeleteConfirm verifies the step-up (a mailed code or the typed phrase) and deletes the
+// account.
+func (c *Client) DeleteConfirm(ctx context.Context, userID, code, phrase string) error {
+	return c.do(ctx, http.MethodPost, "/api/v1/user/delete/confirm", userID, "",
+		map[string]string{"code": code, "phrase": phrase}, nil)
+}
+
+// LinkUnlink detaches a platform identity (kind = "telegram" | "vk") from the caller
+// and returns the refreshed profile in the result.
+func (c *Client) LinkUnlink(ctx context.Context, userID, kind string) (LinkResultResp, error) {
+	var out LinkResultResp
+	err := c.do(ctx, http.MethodPost, "/api/v1/user/link/unlink", userID, "",
+		map[string]string{"kind": kind}, &out)
+	return out, err
+}
+
 // Stats returns the caller's lifetime statistics.
 func (c *Client) Stats(ctx context.Context, userID string) (StatsResp, error) {
 	var out StatsResp

gateway/internal/config/config.go

@@ -36,6 +36,11 @@ type Config struct {
 	// VK launch-parameter signature in-process under it (a pure offline HMAC, no VK API
 	// round-trip). Empty disables the VK auth path (auth.vk is then unregistered).
 	VKAppSecret string
+	// VKID configures the VK ID web login used to link a VK identity from a browser
+	// (the confidential OAuth 2.1 code exchange against id.vk.com). It belongs to a
+	// separate VK "Web" app from VKAppSecret's Mini App, so its credentials are distinct.
+	// Any field empty disables the VK web-link ops (link.vk.*).
+	VKID VKIDConfig
 	// BotLink configures the reverse mTLS channel to the remote Telegram bot. An
 	// empty BotLink.Addr disables the bot channel (out-of-app push and admin relay).
 	BotLink BotLinkConfig
@@ -161,6 +166,22 @@ func DefaultAbuse() AbuseConfig {
 	}
 }
 
+// VKIDConfig holds the VK ID web-login credentials for the confidential
+// authorization-code exchange. AppID is the VK "Web" app's client id; ClientSecret is
+// its protected key; RedirectURI must exactly match the trusted redirect URL registered
+// with the app and the one the frontend uses. All three are required to enable the flow.
+type VKIDConfig struct {
+	AppID        string
+	ClientSecret string
+	RedirectURI  string
+}
+
+// Enabled reports whether VK ID web login is fully configured. When false the gateway
+// leaves the VK web-link ops (link.vk.*) unregistered.
+func (c VKIDConfig) Enabled() bool {
+	return c.AppID != "" && c.ClientSecret != "" && c.RedirectURI != ""
+}
+
 // Load reads the configuration from the environment, applies defaults, and
 // validates the result.
 func Load() (Config, error) {
@@ -174,6 +195,11 @@ func Load() (Config, error) {
 		AdminPassword:   os.Getenv("GATEWAY_ADMIN_PASSWORD"),
 		ValidatorAddr:   os.Getenv("GATEWAY_VALIDATOR_ADDR"),
 		VKAppSecret:     os.Getenv("GATEWAY_VK_APP_SECRET"),
+		VKID: VKIDConfig{
+			AppID:        os.Getenv("GATEWAY_VK_ID_APP_ID"),
+			ClientSecret: os.Getenv("GATEWAY_VK_ID_CLIENT_SECRET"),
+			RedirectURI:  os.Getenv("GATEWAY_VK_ID_REDIRECT_URL"),
+		},
 		SessionCacheMax: defaultSessionCacheMax,
 		RateLimit:       DefaultRateLimit(),
 		Abuse:           DefaultAbuse(),

gateway/internal/connectsrv/metrics.go

@@ -32,6 +32,8 @@ type serverMetrics struct {
 	localColdStart metric.Int64Counter
 	localDictLoad  metric.Int64Counter
 	localPreview   metric.Int64Counter
+	// Clients turned away by the unsupported-engine boot screen (see unsupportedEngineHandler).
+	unsupportedEngine metric.Int64Counter
 }
 
 // newServerMetrics builds the instruments on meter (nil selects a no-op meter),
@@ -63,6 +65,8 @@ func newServerMetrics(meter metric.Meter) *serverMetrics {
 		localColdStart: counterOf(meter, "local_eval_cold_start_total", "App cold starts reported by clients — the denominator for local-move-preview adoption."),
 		localDictLoad:  counterOf(meter, "local_eval_dict_load_total", "Client dictionary loads for the local move preview, by result (fetched, cache_hit or miss)."),
 		localPreview:   counterOf(meter, "local_eval_preview_total", "Client move previews, by path (local on-device, or network fallback)."),
+		unsupportedEngine: counterOf(meter, "unsupported_engine_total",
+			"Clients that hit the unsupported-engine boot screen (the app cannot run), by reason (no_bigint, no_proxy, boot_error, other) and Chromium major — a deduped beacon from the index.html boot guard; the full user agent is logged, not labelled."),
 	}
 
 	gauge, err := meter.Int64ObservableGauge("active_users",
@@ -108,6 +112,16 @@ func (m *serverMetrics) recordBan(ctx context.Context, reason string) {
 	m.banned.Add(ctx, 1, metric.WithAttributes(attribute.String("reason", reason)))
 }
 
+// recordUnsupportedEngine counts one client turned away by the unsupported-engine boot screen,
+// labelled by reason and Chromium major. The caller passes both already reduced to bounded label
+// sets (see normalizeUnsupported) so a spoofed beacon cannot explode the metric cardinality.
+func (m *serverMetrics) recordUnsupportedEngine(ctx context.Context, reason, chromium string) {
+	m.unsupportedEngine.Add(ctx, 1, metric.WithAttributes(
+		attribute.String("reason", reason),
+		attribute.String("chromium", chromium),
+	))
+}
+
 // localEvalReport is the client-reported local move-preview telemetry batch — deltas since
 // the client's previous report. It backs the adoption dashboard: app cold starts vs cached
 // dictionaries vs on-device previews.

gateway/internal/connectsrv/metrics_test.go

@@ -128,3 +128,70 @@ func TestBannedMetric(t *testing.T) {
 		t.Errorf("banned counts = %v, want tripwire=2 honeytoken=1", counts)
 	}
 }
+
+// TestUnsupportedEngineMetric records unsupported-engine beacons through a manual reader and asserts
+// unsupported_engine_total splits by reason and Chromium major.
+func TestUnsupportedEngineMetric(t *testing.T) {
+	ctx := context.Background()
+	reader := sdkmetric.NewManualReader()
+	meter := sdkmetric.NewMeterProvider(sdkmetric.WithReader(reader)).Meter("test")
+	m := newServerMetrics(meter)
+
+	m.recordUnsupportedEngine(ctx, "no_bigint", "66")
+	m.recordUnsupportedEngine(ctx, "no_bigint", "66")
+	m.recordUnsupportedEngine(ctx, "boot_error", "74")
+
+	var rm metricdata.ResourceMetrics
+	if err := reader.Collect(ctx, &rm); err != nil {
+		t.Fatalf("collect: %v", err)
+	}
+	type key struct{ reason, chromium string }
+	counts := map[key]int64{}
+	for _, sm := range rm.ScopeMetrics {
+		for _, md := range sm.Metrics {
+			if md.Name != "unsupported_engine_total" {
+				continue
+			}
+			sum, ok := md.Data.(metricdata.Sum[int64])
+			if !ok {
+				t.Fatalf("unsupported_engine_total is not an int64 sum")
+			}
+			for _, dp := range sum.DataPoints {
+				reason, _ := dp.Attributes.Value(attribute.Key("reason"))
+				chromium, _ := dp.Attributes.Value(attribute.Key("chromium"))
+				counts[key{reason.AsString(), chromium.AsString()}] += dp.Value
+			}
+		}
+	}
+	if got := counts[key{"no_bigint", "66"}]; got != 2 {
+		t.Errorf("unsupported no_bigint/66 = %d, want 2", got)
+	}
+	if got := counts[key{"boot_error", "74"}]; got != 1 {
+		t.Errorf("unsupported boot_error/74 = %d, want 1", got)
+	}
+}
+
+// TestNormalizeUnsupported checks that a beacon's reason and Chromium are reduced to bounded label
+// values, so a spoofed beacon cannot explode the metric cardinality.
+func TestNormalizeUnsupported(t *testing.T) {
+	cases := []struct {
+		reason, chromium         string
+		wantReason, wantChromium string
+	}{
+		{"no_bigint", "66", "no_bigint", "66"},
+		{"no_proxy", " 74 ", "no_proxy", "74"},
+		{"boot_error", "105", "boot_error", "105"},
+		{"garbage", "66", "other", "66"},
+		{"", "", "other", "other"},
+		{"no_bigint", "not-a-number", "no_bigint", "other"},
+		{"no_bigint", "9999", "no_bigint", "other"},
+		{"no_bigint", "0", "no_bigint", "other"},
+		{"no_bigint", "-5", "no_bigint", "other"},
+	}
+	for _, c := range cases {
+		gotR, gotC := normalizeUnsupported(c.reason, c.chromium)
+		if gotR != c.wantReason || gotC != c.wantChromium {
+			t.Errorf("normalizeUnsupported(%q,%q) = %q,%q; want %q,%q", c.reason, c.chromium, gotR, gotC, c.wantReason, c.wantChromium)
+		}
+	}
+}

gateway/internal/connectsrv/server.go

@@ -15,6 +15,7 @@ import (
 	"io"
 	"net"
 	"net/http"
+	"strconv"
 	"strings"
 	"time"
 
@@ -197,6 +198,9 @@ func (s *Server) HTTPHandler() http.Handler {
 	mux.Handle("/dl/", s.exportDownloadHandler())
 	// The client posts its local-move-preview adoption telemetry here (session-gated).
 	mux.Handle("/metrics/local-eval", s.localEvalMetricsHandler())
+	// The index.html boot guard beacons here when it turns a client away on the unsupported-engine
+	// screen (the app cannot run). Unauthenticated — the client never booted — but rate-limited.
+	mux.Handle("/telemetry/unsupported", s.unsupportedEngineHandler())
 	// The embedded UI: the game SPA under /app/ (web), /telegram/ (the Telegram Mini
 	// App) and /vk/ (the VK Mini App) — the single-origin model (docs/ARCHITECTURE.md
 	// §13). All sit below the h2c wrap so the Connect edge (a more specific prefix) keeps
@@ -582,6 +586,76 @@ func clampReport(r *localEvalReport) {
 	clamp(&r.PreviewNetwork)
 }
 
+// unsupportedEngineBeacon is the small fire-and-forget report the index.html boot guard sends when
+// it turns a client away on the unsupported-engine screen (no BigInt/Proxy, or an uncaught boot
+// error). It is deduped client-side (one per device / app version / reason).
+type unsupportedEngineBeacon struct {
+	Reason   string `json:"reason"`
+	Chromium string `json:"chromium"`
+	Version  string `json:"version"`
+	UA       string `json:"ua"`
+}
+
+// unsupportedEngineHandler folds one unsupported-engine beacon into the edge counter. It is
+// unauthenticated (the client never booted, so it carries no session) but per-IP rate-limited with
+// the public limiter and body-capped. reason and the Chromium major are reduced to bounded label
+// sets (normalizeUnsupported) so a spoofed beacon cannot inflate the metric cardinality; the full
+// user agent is logged, not labelled. Only POST; the reply is always 204.
+func (s *Server) unsupportedEngineHandler() http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		ip := peerIP(r.RemoteAddr, r.Header)
+		if !s.limiter.Allow("public:"+ip, s.publicPolicy) {
+			s.noteRateLimited(r.Context(), classPublic, ip, "unsupported")
+			http.Error(w, "rate limited", http.StatusTooManyRequests)
+			return
+		}
+		var b unsupportedEngineBeacon
+		if err := json.NewDecoder(io.LimitReader(r.Body, 2048)).Decode(&b); err != nil {
+			http.Error(w, "bad request", http.StatusBadRequest)
+			return
+		}
+		reason, chromium := normalizeUnsupported(b.Reason, b.Chromium)
+		s.metrics.recordUnsupportedEngine(r.Context(), reason, chromium)
+		s.log.Info("unsupported engine",
+			zap.String("reason", reason),
+			zap.String("chromium", chromium),
+			zap.String("app_version", truncate(b.Version, 40)),
+			zap.String("user_agent", truncate(b.UA, 400)),
+		)
+		w.WriteHeader(http.StatusNoContent)
+	})
+}
+
+// normalizeUnsupported reduces a beacon's reason and Chromium fields to bounded label values, so a
+// spoofed beacon cannot explode the metric cardinality: reason is allow-listed, and Chromium is
+// parsed as a major version kept only within a plausible range, otherwise "other".
+func normalizeUnsupported(reason, chromium string) (string, string) {
+	switch reason {
+	case "no_bigint", "no_proxy", "boot_error":
+		// a recognised reason — keep as-is
+	default:
+		reason = "other"
+	}
+	major := "other"
+	if n, err := strconv.Atoi(strings.TrimSpace(chromium)); err == nil && n >= 1 && n <= 199 {
+		major = strconv.Itoa(n)
+	}
+	return reason, major
+}
+
+// truncate bounds a logged, client-supplied string to n bytes (a spoofed beacon field is not
+// trusted to be small).
+func truncate(s string, n int) string {
+	if len(s) > n {
+		return s[:n]
+	}
+	return s
+}
+
 // resolve extracts and resolves the Authorization bearer token to an account id
 // and its guest flag, returning a Connect Unauthenticated error when it is missing
 // or unknown.

gateway/internal/connectsrv/telemetry_test.go

@@ -0,0 +1,81 @@
+package connectsrv_test
+
+import (
+	"bytes"
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"go.opentelemetry.io/otel/attribute"
+	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
+	"go.opentelemetry.io/otel/sdk/metric/metricdata"
+
+	"scrabble/gateway/internal/config"
+	"scrabble/gateway/internal/connectsrv"
+	"scrabble/gateway/internal/ratelimit"
+)
+
+// TestUnsupportedEngineHandler drives the /telemetry/unsupported beacon route end to end: a POST
+// increments unsupported_engine_total with the normalised labels and replies 204; a GET is 405.
+func TestUnsupportedEngineHandler(t *testing.T) {
+	reader := sdkmetric.NewManualReader()
+	meter := sdkmetric.NewMeterProvider(sdkmetric.WithReader(reader)).Meter("test")
+	edge := connectsrv.NewServer(connectsrv.Deps{
+		Limiter:   ratelimit.New(),
+		RateLimit: config.DefaultRateLimit(),
+		Meter:     meter,
+	})
+	srv := httptest.NewServer(edge.HTTPHandler())
+	defer srv.Close()
+	url := srv.URL + "/telemetry/unsupported"
+
+	// A GET is rejected.
+	getResp, err := http.Get(url)
+	if err != nil {
+		t.Fatalf("get: %v", err)
+	}
+	getResp.Body.Close()
+	if getResp.StatusCode != http.StatusMethodNotAllowed {
+		t.Errorf("GET status = %d, want 405", getResp.StatusCode)
+	}
+
+	// A POST is accepted (204) and folded into the counter with normalised labels.
+	body := `{"reason":"no_bigint","chromium":"66","version":"v1.2.3","ua":"Mozilla/5.0 ... Chrome/66"}`
+	resp, err := http.Post(url, "application/json", bytes.NewBufferString(body))
+	if err != nil {
+		t.Fatalf("post: %v", err)
+	}
+	resp.Body.Close()
+	if resp.StatusCode != http.StatusNoContent {
+		t.Errorf("POST status = %d, want 204", resp.StatusCode)
+	}
+
+	var rm metricdata.ResourceMetrics
+	if err := reader.Collect(context.Background(), &rm); err != nil {
+		t.Fatalf("collect: %v", err)
+	}
+	var total int64
+	for _, sm := range rm.ScopeMetrics {
+		for _, md := range sm.Metrics {
+			if md.Name != "unsupported_engine_total" {
+				continue
+			}
+			sum, ok := md.Data.(metricdata.Sum[int64])
+			if !ok {
+				t.Fatalf("unsupported_engine_total is not an int64 sum")
+			}
+			for _, dp := range sum.DataPoints {
+				reason, _ := dp.Attributes.Value(attribute.Key("reason"))
+				chromium, _ := dp.Attributes.Value(attribute.Key("chromium"))
+				if reason.AsString() != "no_bigint" || chromium.AsString() != "66" {
+					t.Errorf("labels = %s/%s, want no_bigint/66", reason.AsString(), chromium.AsString())
+				}
+				total += dp.Value
+			}
+		}
+	}
+	if total != 1 {
+		t.Errorf("unsupported_engine_total = %d, want 1", total)
+	}
+}

gateway/internal/transcode/encode.go

@@ -37,6 +37,17 @@ func encodeAck(ok bool) []byte {
 	return b.FinishedBytes()
 }
 
+// encodeDeleteRequestResult builds an AccountDeleteRequestResult payload reporting which
+// deletion step-up the account uses ("email" | "phrase").
+func encodeDeleteRequestResult(method string) []byte {
+	b := flatbuffers.NewBuilder(32)
+	m := b.CreateString(method)
+	fb.AccountDeleteRequestResultStart(b)
+	fb.AccountDeleteRequestResultAddMethod(b, m)
+	b.Finish(fb.AccountDeleteRequestResultEnd(b))
+	return b.FinishedBytes()
+}
+
 // encodeConfirmLinkResult builds an EmailConfirmLinkResult payload, embedding the
 // minted Session for a login. All strings and the nested Session table are built
 // before the result table is opened.
@@ -76,6 +87,7 @@ func encodeProfile(p backendclient.ProfileResp) []byte {
 	tz := b.CreateString(p.TimeZone)
 	awayStart := b.CreateString(p.AwayStart)
 	awayEnd := b.CreateString(p.AwayEnd)
+	email := b.CreateString(p.Email)
 	// Build the banner table (and its children) before opening Profile: FlatBuffers
 	// forbids a nested table while another is under construction.
 	var banner flatbuffers.UOffsetT
@@ -96,6 +108,9 @@ func encodeProfile(p backendclient.ProfileResp) []byte {
 	fb.ProfileAddAwayEnd(b, awayEnd)
 	fb.ProfileAddNotificationsInAppOnly(b, p.NotificationsInAppOnly)
 	fb.ProfileAddVariantPreferences(b, prefs)
+	fb.ProfileAddEmail(b, email)
+	fb.ProfileAddTelegramLinked(b, p.TelegramLinked)
+	fb.ProfileAddVkLinked(b, p.VkLinked)
 	if p.Banner != nil {
 		fb.ProfileAddBanner(b, banner)
 	}

gateway/internal/transcode/transcode.go

@@ -14,6 +14,7 @@ import (
 	"scrabble/gateway/internal/backendclient"
 	"scrabble/gateway/internal/connector"
 	"scrabble/gateway/internal/vkauth"
+	"scrabble/gateway/internal/vkid"
 	fb "scrabble/pkg/fbs/scrabblefb"
 )
 
@@ -152,6 +153,15 @@ func WithVKAuth(secret string) Option {
 	}
 }
 
+// WithVKLink registers the VK web-link ops (link.vk.confirm/merge), which complete a
+// browser VK ID authorization via the server-side code exchange. A nil exchanger leaves
+// them unregistered, so the ops are unknown wherever VK ID web login is not configured.
+func WithVKLink(ex VKIDExchanger) Option {
+	return func(r *Registry, backend *backendclient.Client) {
+		registerVKLinkOps(r, backend, ex)
+	}
+}
+
 // Lookup returns the operation for messageType, and whether it is registered.
 func (r *Registry) Lookup(messageType string) (Op, bool) {
 	op, ok := r.ops[messageType]
@@ -172,6 +182,9 @@ func DomainCode(err error) (string, bool) {
 	if errors.Is(err, vkauth.ErrInvalid) {
 		return "invalid_vk_params", true
 	}
+	if errors.Is(err, vkid.ErrInvalid) {
+		return "invalid_vk_id", true
+	}
 	if errors.Is(err, connector.ErrInvalidLoginWidget) {
 		return "invalid_login_widget", true
 	}

gateway/internal/transcode/transcode_link.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"scrabble/gateway/internal/backendclient"
+	"scrabble/gateway/internal/vkid"
 	fb "scrabble/pkg/fbs/scrabblefb"
 )
 
@@ -18,6 +19,13 @@ const (
 	MsgLinkEmailMerge     = "link.email.merge"
 	MsgLinkTelegram       = "link.telegram.confirm"
 	MsgLinkTelegramMerge  = "link.telegram.merge"
+	MsgLinkVK             = "link.vk.confirm"
+	MsgLinkVKMerge        = "link.vk.merge"
+	MsgLinkUnlink         = "link.unlink"
+	MsgEmailChangeRequest = "link.email.change.request"
+	MsgEmailChangeConfirm = "link.email.change.confirm"
+	MsgAccountDeleteReq   = "account.delete.request"
+	MsgAccountDeleteConf  = "account.delete.confirm"
 )
 
 // registerLinkOps adds the linking & merge operations. The telegram ops need the
@@ -26,6 +34,11 @@ func registerLinkOps(r *Registry, backend *backendclient.Client, tg TelegramVali
 	r.ops[MsgLinkEmailRequest] = Op{Handler: linkEmailRequestHandler(backend), Auth: true, Email: true}
 	r.ops[MsgLinkEmailConfirm] = Op{Handler: linkEmailConfirmHandler(backend), Auth: true, Email: true}
 	r.ops[MsgLinkEmailMerge] = Op{Handler: linkEmailMergeHandler(backend), Auth: true, Email: true}
+	r.ops[MsgLinkUnlink] = Op{Handler: linkUnlinkHandler(backend), Auth: true}
+	r.ops[MsgEmailChangeRequest] = Op{Handler: changeEmailRequestHandler(backend), Auth: true, Email: true}
+	r.ops[MsgEmailChangeConfirm] = Op{Handler: changeEmailConfirmHandler(backend), Auth: true, Email: true}
+	r.ops[MsgAccountDeleteReq] = Op{Handler: deleteRequestHandler(backend), Auth: true, Email: true}
+	r.ops[MsgAccountDeleteConf] = Op{Handler: deleteConfirmHandler(backend), Auth: true}
 	if tg != nil {
 		r.ops[MsgLinkTelegram] = Op{Handler: linkTelegramHandler(backend, tg, false), Auth: true}
 		r.ops[MsgLinkTelegramMerge] = Op{Handler: linkTelegramHandler(backend, tg, true), Auth: true}
@@ -64,6 +77,65 @@ func linkEmailMergeHandler(backend *backendclient.Client) Handler {
 	}
 }
 
+// changeEmailRequestHandler mails a confirm-code to a new address for an email change.
+func changeEmailRequestHandler(backend *backendclient.Client) Handler {
+	return func(ctx context.Context, req Request) ([]byte, error) {
+		in := fb.GetRootAsLinkEmailRequest(req.Payload, 0)
+		if err := backend.ChangeEmailRequest(ctx, req.UserID, string(in.Email())); err != nil {
+			return nil, err
+		}
+		return encodeAck(true), nil
+	}
+}
+
+// changeEmailConfirmHandler verifies the code and switches the account's email, returning
+// the refreshed link result (status "changed" + the updated profile).
+func changeEmailConfirmHandler(backend *backendclient.Client) Handler {
+	return func(ctx context.Context, req Request) ([]byte, error) {
+		in := fb.GetRootAsLinkEmailConfirm(req.Payload, 0)
+		res, err := backend.ChangeEmailConfirm(ctx, req.UserID, string(in.Email()), string(in.Code()))
+		if err != nil {
+			return nil, err
+		}
+		return encodeLinkResult(res), nil
+	}
+}
+
+// deleteRequestHandler starts account deletion, returning which step-up the account uses.
+func deleteRequestHandler(backend *backendclient.Client) Handler {
+	return func(ctx context.Context, req Request) ([]byte, error) {
+		res, err := backend.DeleteRequest(ctx, req.UserID)
+		if err != nil {
+			return nil, err
+		}
+		return encodeDeleteRequestResult(res.Method), nil
+	}
+}
+
+// deleteConfirmHandler verifies the step-up proof and deletes the account.
+func deleteConfirmHandler(backend *backendclient.Client) Handler {
+	return func(ctx context.Context, req Request) ([]byte, error) {
+		in := fb.GetRootAsAccountDeleteConfirm(req.Payload, 0)
+		if err := backend.DeleteConfirm(ctx, req.UserID, string(in.Code()), string(in.Phrase())); err != nil {
+			return nil, err
+		}
+		return encodeAck(true), nil
+	}
+}
+
+// linkUnlinkHandler detaches a platform identity (telegram|vk) from the caller and
+// returns the refreshed link result (status "unlinked" + the updated profile).
+func linkUnlinkHandler(backend *backendclient.Client) Handler {
+	return func(ctx context.Context, req Request) ([]byte, error) {
+		in := fb.GetRootAsLinkUnlinkRequest(req.Payload, 0)
+		res, err := backend.LinkUnlink(ctx, req.UserID, string(in.Kind()))
+		if err != nil {
+			return nil, err
+		}
+		return encodeLinkResult(res), nil
+	}
+}
+
 // linkTelegramHandler validates Login Widget data via the connector and then calls
 // the backend's link or merge endpoint with the trusted Telegram external id.
 func linkTelegramHandler(backend *backendclient.Client, tg TelegramValidator, merge bool) Handler {
@@ -85,3 +157,44 @@ func linkTelegramHandler(backend *backendclient.Client, tg TelegramValidator, me
 		return encodeLinkResult(res), nil
 	}
 }
+
+// VKIDExchanger completes a VK ID web authorization-code exchange, returning the
+// launching user's trusted VK identity. It is satisfied by *vkid.Exchanger and lets the
+// VK web-link ops resolve a browser VK login, which — unlike the Mini App path — has no
+// offline launch signature to verify.
+type VKIDExchanger interface {
+	Exchange(ctx context.Context, code, deviceID, codeVerifier string) (vkid.Identity, error)
+}
+
+// registerVKLinkOps adds the VK web-link ops when a VK ID exchanger is configured; a nil
+// exchanger leaves them unregistered (VK ID web login not configured).
+func registerVKLinkOps(r *Registry, backend *backendclient.Client, ex VKIDExchanger) {
+	if ex == nil {
+		return
+	}
+	r.ops[MsgLinkVK] = Op{Handler: linkVKHandler(backend, ex, false), Auth: true}
+	r.ops[MsgLinkVKMerge] = Op{Handler: linkVKHandler(backend, ex, true), Auth: true}
+}
+
+// linkVKHandler completes the VK ID code exchange (server-side, under the app's
+// protected key) and then calls the backend's link or merge endpoint with the trusted
+// VK external id.
+func linkVKHandler(backend *backendclient.Client, ex VKIDExchanger, merge bool) Handler {
+	return func(ctx context.Context, req Request) ([]byte, error) {
+		in := fb.GetRootAsLinkVKRequest(req.Payload, 0)
+		user, err := ex.Exchange(ctx, string(in.Code()), string(in.DeviceId()), string(in.CodeVerifier()))
+		if err != nil {
+			return nil, err
+		}
+		var res backendclient.LinkResultResp
+		if merge {
+			res, err = backend.LinkVKMerge(ctx, req.UserID, user.ExternalID)
+		} else {
+			res, err = backend.LinkVK(ctx, req.UserID, user.ExternalID)
+		}
+		if err != nil {
+			return nil, err
+		}
+		return encodeLinkResult(res), nil
+	}
+}

gateway/internal/transcode/transcode_vk_link_test.go

@@ -0,0 +1,90 @@
+package transcode_test
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"testing"
+
+	flatbuffers "github.com/google/flatbuffers/go"
+
+	"scrabble/gateway/internal/transcode"
+	"scrabble/gateway/internal/vkid"
+	fb "scrabble/pkg/fbs/scrabblefb"
+)
+
+func linkVKPayload(code, deviceID, verifier string) []byte {
+	b := flatbuffers.NewBuilder(64)
+	c := b.CreateString(code)
+	d := b.CreateString(deviceID)
+	v := b.CreateString(verifier)
+	fb.LinkVKRequestStart(b)
+	fb.LinkVKRequestAddCode(b, c)
+	fb.LinkVKRequestAddDeviceId(b, d)
+	fb.LinkVKRequestAddCodeVerifier(b, v)
+	b.Finish(fb.LinkVKRequestEnd(b))
+	return b.FinishedBytes()
+}
+
+// fakeVKIDExchanger records the exchange inputs and returns a canned identity.
+type fakeVKIDExchanger struct {
+	id                              vkid.Identity
+	err                             error
+	gotCode, gotDevice, gotVerifier string
+}
+
+func (f *fakeVKIDExchanger) Exchange(_ context.Context, code, deviceID, codeVerifier string) (vkid.Identity, error) {
+	f.gotCode, f.gotDevice, f.gotVerifier = code, deviceID, codeVerifier
+	return f.id, f.err
+}
+
+func TestLinkVKExchangesAndForwards(t *testing.T) {
+	var gotExternalID string
+	backend, cleanup := fakeBackend(t, func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/api/v1/user/link/vk" {
+			t.Errorf("path = %q", r.URL.Path)
+		}
+		var body struct {
+			ExternalID string `json:"external_id"`
+		}
+		_ = json.NewDecoder(r.Body).Decode(&body)
+		gotExternalID = body.ExternalID
+		_, _ = w.Write([]byte(`{"status":"linked"}`))
+	})
+	defer cleanup()
+
+	ex := &fakeVKIDExchanger{id: vkid.Identity{ExternalID: "777"}}
+	reg := transcode.NewRegistry(backend, nil, transcode.WithVKLink(ex))
+	op, ok := reg.Lookup(transcode.MsgLinkVK)
+	if !ok {
+		t.Fatal("link.vk.confirm not registered")
+	}
+	payload, err := op.Handler(context.Background(), transcode.Request{UserID: "u-1", Payload: linkVKPayload("the-code", "dev-1", "verifier-1")})
+	if err != nil {
+		t.Fatalf("handler: %v", err)
+	}
+	// The PKCE inputs from the wire must reach the exchanger verbatim...
+	if ex.gotCode != "the-code" || ex.gotDevice != "dev-1" || ex.gotVerifier != "verifier-1" {
+		t.Errorf("exchange got %q/%q/%q", ex.gotCode, ex.gotDevice, ex.gotVerifier)
+	}
+	// ...and the resolved vk id must be the one forwarded to the backend.
+	if gotExternalID != "777" {
+		t.Errorf("backend external_id = %q, want 777", gotExternalID)
+	}
+	if string(fb.GetRootAsLinkResult(payload, 0).Status()) != "linked" {
+		t.Error("expected a linked result")
+	}
+}
+
+func TestLinkVKUnregisteredWithoutExchanger(t *testing.T) {
+	backend, cleanup := fakeBackend(t, func(http.ResponseWriter, *http.Request) {})
+	defer cleanup()
+
+	reg := transcode.NewRegistry(backend, nil)
+	if _, ok := reg.Lookup(transcode.MsgLinkVK); ok {
+		t.Error("link.vk.confirm must be unregistered when no VK ID exchanger is configured")
+	}
+	if _, ok := reg.Lookup(transcode.MsgLinkVKMerge); ok {
+		t.Error("link.vk.merge must be unregistered when no VK ID exchanger is configured")
+	}
+}

gateway/internal/vkid/vkid.go

@@ -0,0 +1,163 @@
+// Package vkid completes VK ID web authorization on the server. A browser linking a
+// VK identity has no signed Mini App launch parameters (that offline HMAC path is
+// vkauth); instead the frontend runs the VK ID raw OAuth 2.1 flow (PKCE) and hands the
+// gateway the authorization code, which the gateway exchanges — confidentially, under
+// the app's protected key — for the launching user's trusted VK id. Unlike the Mini App
+// path this makes an outbound call to VK (there is no offline verification for the web
+// flow). See docs/ARCHITECTURE.md §12.
+package vkid
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+const (
+	// tokenEndpoint is VK ID's OAuth 2.1 token endpoint. The frontend obtains the
+	// authorization code against the same host, so the confidential exchange targets it
+	// too. It is a fixed constant (not user input), so the outbound request carries no
+	// SSRF risk.
+	tokenEndpoint = "https://id.vk.com/oauth2/auth"
+	// exchangeTimeout bounds one code-for-token exchange. Linking is interactive, so an
+	// unreachable VK must fail fast rather than hold the request open.
+	exchangeTimeout = 10 * time.Second
+	// maxResponseBytes caps the token-response read to bound memory on an oversized body.
+	maxResponseBytes = 1 << 16
+)
+
+// ErrInvalid reports an authorization fault: the exchange was rejected or yielded no vk
+// user id (a bad or expired code, a mismatched verifier or redirect). It is distinct
+// from a transport failure reaching VK, which surfaces as a wrapped error.
+var ErrInvalid = errors.New("vkid: vk id authorization exchange failed")
+
+// Identity is the user resolved from a completed VK ID exchange. ExternalID is the vk
+// user id, used as the identities external_id.
+type Identity struct {
+	ExternalID string
+}
+
+// numericID accepts a VK user id that the token endpoint returns inconsistently as a
+// JSON string or a JSON number, normalising both to their decimal string form (empty
+// for a null or absent field).
+type numericID string
+
+func (n *numericID) UnmarshalJSON(b []byte) error {
+	s := strings.Trim(string(b), `"`)
+	if s == "null" {
+		s = ""
+	}
+	*n = numericID(s)
+	return nil
+}
+
+// Exchanger completes VK ID confidential authorization-code exchanges for one app.
+type Exchanger struct {
+	appID        string
+	clientSecret string
+	redirectURI  string
+	endpoint     string
+	httpClient   *http.Client
+}
+
+// New constructs an Exchanger for the app credentials. redirectURI must equal the
+// trusted redirect URL registered with the app and the one the frontend used, or VK
+// rejects the exchange.
+func New(appID, clientSecret, redirectURI string) *Exchanger {
+	return &Exchanger{
+		appID:        appID,
+		clientSecret: clientSecret,
+		redirectURI:  redirectURI,
+		endpoint:     tokenEndpoint,
+		httpClient:   &http.Client{Timeout: exchangeTimeout},
+	}
+}
+
+// Exchange completes the authorization-code grant and returns the trusted vk user id.
+// code, deviceID and codeVerifier are the PKCE inputs the frontend obtained from the VK
+// ID authorization redirect; the exchange authenticates with the app's protected key.
+func (e *Exchanger) Exchange(ctx context.Context, code, deviceID, codeVerifier string) (Identity, error) {
+	if code == "" || deviceID == "" || codeVerifier == "" {
+		return Identity{}, ErrInvalid
+	}
+	form := url.Values{
+		"grant_type":    {"authorization_code"},
+		"code":          {code},
+		"code_verifier": {codeVerifier},
+		"device_id":     {deviceID},
+		"client_id":     {e.appID},
+		"client_secret": {e.clientSecret},
+		"redirect_uri":  {e.redirectURI},
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, e.endpoint, strings.NewReader(form.Encode()))
+	if err != nil {
+		return Identity{}, fmt.Errorf("vkid: build exchange request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Set("Accept", "application/json")
+	resp, err := e.httpClient.Do(req)
+	if err != nil {
+		return Identity{}, fmt.Errorf("vkid: exchange request: %w", err)
+	}
+	defer resp.Body.Close()
+	body, err := io.ReadAll(io.LimitReader(resp.Body, maxResponseBytes))
+	if err != nil {
+		return Identity{}, fmt.Errorf("vkid: read exchange response: %w", err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		// VK answers 400 with {error, error_description} on a bad/expired code or a
+		// verifier/redirect mismatch — an authorization fault, not a transport error.
+		return Identity{}, ErrInvalid
+	}
+	var out struct {
+		UserID  numericID `json:"user_id"`
+		IDToken string    `json:"id_token"`
+		Error   string    `json:"error"`
+	}
+	if err := json.Unmarshal(body, &out); err != nil {
+		return Identity{}, ErrInvalid
+	}
+	if out.Error != "" {
+		return Identity{}, ErrInvalid
+	}
+	uid := string(out.UserID)
+	if uid == "" || uid == "0" {
+		uid = subjectFromIDToken(out.IDToken)
+	}
+	if uid == "" {
+		return Identity{}, ErrInvalid
+	}
+	return Identity{ExternalID: uid}, nil
+}
+
+// subjectFromIDToken extracts the OIDC subject (the vk user id) from the payload of a
+// VK ID id_token. The token arrives inside a direct TLS response from VK, so its
+// signature is not re-verified here; the claim is only a fallback for a response that
+// omits an explicit user_id.
+func subjectFromIDToken(idToken string) string {
+	parts := strings.Split(idToken, ".")
+	if len(parts) != 3 {
+		return ""
+	}
+	payload, err := base64.RawURLEncoding.DecodeString(parts[1])
+	if err != nil {
+		return ""
+	}
+	var claims struct {
+		Sub numericID `json:"sub"`
+	}
+	if err := json.Unmarshal(payload, &claims); err != nil {
+		return ""
+	}
+	if s := string(claims.Sub); s != "0" {
+		return s
+	}
+	return ""
+}

gateway/internal/vkid/vkid_test.go

@@ -0,0 +1,131 @@
+package vkid
+
+import (
+	"context"
+	"encoding/base64"
+	"errors"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+)
+
+// testExchanger builds an Exchanger pointed at a test server.
+func testExchanger(endpoint string) *Exchanger {
+	return &Exchanger{
+		appID:        "app-1",
+		clientSecret: "secret-1",
+		redirectURI:  "https://example.test/app/",
+		endpoint:     endpoint,
+		httpClient:   &http.Client{},
+	}
+}
+
+func TestExchangeSuccessSendsConfidentialPKCE(t *testing.T) {
+	var gotForm url.Values
+	var gotContentType string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotContentType = r.Header.Get("Content-Type")
+		body, _ := io.ReadAll(r.Body)
+		gotForm, _ = url.ParseQuery(string(body))
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = io.WriteString(w, `{"user_id":"12345","access_token":"a","id_token":"h.e.s"}`)
+	}))
+	defer srv.Close()
+
+	id, err := testExchanger(srv.URL).Exchange(context.Background(), "the-code", "dev-9", "verifier-xyz")
+	if err != nil {
+		t.Fatalf("Exchange: %v", err)
+	}
+	if id.ExternalID != "12345" {
+		t.Fatalf("ExternalID = %q, want 12345", id.ExternalID)
+	}
+	if gotContentType != "application/x-www-form-urlencoded" {
+		t.Errorf("Content-Type = %q", gotContentType)
+	}
+	// The confidential exchange must carry the PKCE inputs and the app credentials.
+	want := map[string]string{
+		"grant_type":    "authorization_code",
+		"code":          "the-code",
+		"code_verifier": "verifier-xyz",
+		"device_id":     "dev-9",
+		"client_id":     "app-1",
+		"client_secret": "secret-1",
+		"redirect_uri":  "https://example.test/app/",
+	}
+	for k, v := range want {
+		if gotForm.Get(k) != v {
+			t.Errorf("form[%s] = %q, want %q", k, gotForm.Get(k), v)
+		}
+	}
+}
+
+func TestExchangeAcceptsNumericUserID(t *testing.T) {
+	// VK returns user_id as a bare JSON number in some responses; it must parse too.
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.WriteString(w, `{"user_id":1234567890,"access_token":"a"}`)
+	}))
+	defer srv.Close()
+
+	id, err := testExchanger(srv.URL).Exchange(context.Background(), "c", "d", "v")
+	if err != nil {
+		t.Fatalf("Exchange: %v", err)
+	}
+	if id.ExternalID != "1234567890" {
+		t.Fatalf("ExternalID = %q, want 1234567890", id.ExternalID)
+	}
+}
+
+func TestExchangeFallsBackToIDTokenSub(t *testing.T) {
+	sub := "987654321"
+	payload := base64.RawURLEncoding.EncodeToString([]byte(`{"sub":"` + sub + `"}`))
+	idToken := "header." + payload + ".sig"
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.WriteString(w, `{"access_token":"a","id_token":"`+idToken+`"}`)
+	}))
+	defer srv.Close()
+
+	id, err := testExchanger(srv.URL).Exchange(context.Background(), "c", "d", "v")
+	if err != nil {
+		t.Fatalf("Exchange: %v", err)
+	}
+	if id.ExternalID != sub {
+		t.Fatalf("ExternalID = %q, want %q (from id_token sub)", id.ExternalID, sub)
+	}
+}
+
+func TestExchangeRejectedIsErrInvalid(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusBadRequest)
+		_, _ = io.WriteString(w, `{"error":"invalid_grant","error_description":"code expired"}`)
+	}))
+	defer srv.Close()
+
+	_, err := testExchanger(srv.URL).Exchange(context.Background(), "c", "d", "v")
+	if !errors.Is(err, ErrInvalid) {
+		t.Fatalf("err = %v, want ErrInvalid", err)
+	}
+}
+
+func TestExchangeEmptyInputsFailFast(t *testing.T) {
+	// Missing PKCE inputs are rejected without any network call.
+	ex := testExchanger("http://127.0.0.1:0/never")
+	for _, args := range [][3]string{{"", "d", "v"}, {"c", "", "v"}, {"c", "d", ""}} {
+		if _, err := ex.Exchange(context.Background(), args[0], args[1], args[2]); !errors.Is(err, ErrInvalid) {
+			t.Errorf("Exchange%v err = %v, want ErrInvalid", args, err)
+		}
+	}
+}
+
+func TestExchangeTransportErrorIsNotErrInvalid(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(http.ResponseWriter, *http.Request) {}))
+	srv.Close() // closed listener → connection refused
+	_, err := testExchanger(srv.URL).Exchange(context.Background(), "c", "d", "v")
+	if err == nil {
+		t.Fatal("want a transport error")
+	}
+	if errors.Is(err, ErrInvalid) {
+		t.Fatalf("transport error must not be ErrInvalid: %v", err)
+	}
+}

pkg/fbs/scrabble.fbs

@@ -224,6 +224,12 @@ table Profile {
   // variant_preferences is the set of game variants the player allows themselves to be
   // matched into (engine.Variant labels), Erudit-first; the New Game picker is gated by it.
   variant_preferences:[string];
+  // email is the account's confirmed email address ("" when none); telegram_linked and
+  // vk_linked report whether a platform identity is attached. They drive the profile's
+  // link / unlink / change-email controls (all added trailing — backward-compatible).
+  email:string;
+  telegram_linked:bool;
+  vk_linked:bool;
 }
 
 // BlockStatus reports the caller's current manual block. The UI fetches it after any operation
@@ -495,6 +501,36 @@ table LinkTelegramRequest {
   data:string;
 }
 
+// LinkVKRequest carries a VK ID web authorization for attaching a VK identity to the
+// current account. The fields are the PKCE code-exchange inputs the frontend obtains
+// from the VK ID SDK (One Tap): the authorization code, the device id issued with it,
+// and the PKCE code verifier. The gateway completes the confidential code exchange
+// server-side (under the app's protected key) to obtain the trusted vk user id.
+table LinkVKRequest {
+  code:string;
+  device_id:string;
+  code_verifier:string;
+}
+
+// LinkUnlinkRequest detaches a platform identity (kind = "telegram" | "vk") from the
+// caller's account; email is never unlinked (it is changed).
+table LinkUnlinkRequest {
+  kind:string;
+}
+
+// AccountDeleteConfirm carries the account-deletion step-up proof: a mailed code (email
+// accounts) or the typed phrase (platform-only accounts).
+table AccountDeleteConfirm {
+  code:string;
+  phrase:string;
+}
+
+// AccountDeleteRequestResult reports which deletion step-up the account uses: "email"
+// (a code was mailed) or "phrase" (type the confirmation phrase).
+table AccountDeleteRequestResult {
+  method:string;
+}
+
 // LinkResult is the unified result of a confirm or merge step. status is "linked"
 // (bound to the caller), "merge_required" (the identity belongs to another account —
 // the secondary_* fields summarise it for the irreversible confirmation), or

pkg/fbs/scrabblefb/AccountDeleteConfirm.go

@@ -0,0 +1,71 @@
+// Code generated by the FlatBuffers compiler. DO NOT EDIT.
+
+package scrabblefb
+
+import (
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type AccountDeleteConfirm struct {
+	_tab flatbuffers.Table
+}
+
+func GetRootAsAccountDeleteConfirm(buf []byte, offset flatbuffers.UOffsetT) *AccountDeleteConfirm {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &AccountDeleteConfirm{}
+	x.Init(buf, n+offset)
+	return x
+}
+
+func FinishAccountDeleteConfirmBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.Finish(offset)
+}
+
+func GetSizePrefixedRootAsAccountDeleteConfirm(buf []byte, offset flatbuffers.UOffsetT) *AccountDeleteConfirm {
+	n := flatbuffers.GetUOffsetT(buf[offset+flatbuffers.SizeUint32:])
+	x := &AccountDeleteConfirm{}
+	x.Init(buf, n+offset+flatbuffers.SizeUint32)
+	return x
+}
+
+func FinishSizePrefixedAccountDeleteConfirmBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.FinishSizePrefixed(offset)
+}
+
+func (rcv *AccountDeleteConfirm) Init(buf []byte, i flatbuffers.UOffsetT) {
+	rcv._tab.Bytes = buf
+	rcv._tab.Pos = i
+}
+
+func (rcv *AccountDeleteConfirm) Table() flatbuffers.Table {
+	return rcv._tab
+}
+
+func (rcv *AccountDeleteConfirm) Code() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(4))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *AccountDeleteConfirm) Phrase() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(6))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func AccountDeleteConfirmStart(builder *flatbuffers.Builder) {
+	builder.StartObject(2)
+}
+func AccountDeleteConfirmAddCode(builder *flatbuffers.Builder, code flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(code), 0)
+}
+func AccountDeleteConfirmAddPhrase(builder *flatbuffers.Builder, phrase flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(1, flatbuffers.UOffsetT(phrase), 0)
+}
+func AccountDeleteConfirmEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
+	return builder.EndObject()
+}

pkg/fbs/scrabblefb/AccountDeleteRequestResult.go

@@ -0,0 +1,60 @@
+// Code generated by the FlatBuffers compiler. DO NOT EDIT.
+
+package scrabblefb
+
+import (
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type AccountDeleteRequestResult struct {
+	_tab flatbuffers.Table
+}
+
+func GetRootAsAccountDeleteRequestResult(buf []byte, offset flatbuffers.UOffsetT) *AccountDeleteRequestResult {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &AccountDeleteRequestResult{}
+	x.Init(buf, n+offset)
+	return x
+}
+
+func FinishAccountDeleteRequestResultBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.Finish(offset)
+}
+
+func GetSizePrefixedRootAsAccountDeleteRequestResult(buf []byte, offset flatbuffers.UOffsetT) *AccountDeleteRequestResult {
+	n := flatbuffers.GetUOffsetT(buf[offset+flatbuffers.SizeUint32:])
+	x := &AccountDeleteRequestResult{}
+	x.Init(buf, n+offset+flatbuffers.SizeUint32)
+	return x
+}
+
+func FinishSizePrefixedAccountDeleteRequestResultBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.FinishSizePrefixed(offset)
+}
+
+func (rcv *AccountDeleteRequestResult) Init(buf []byte, i flatbuffers.UOffsetT) {
+	rcv._tab.Bytes = buf
+	rcv._tab.Pos = i
+}
+
+func (rcv *AccountDeleteRequestResult) Table() flatbuffers.Table {
+	return rcv._tab
+}
+
+func (rcv *AccountDeleteRequestResult) Method() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(4))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func AccountDeleteRequestResultStart(builder *flatbuffers.Builder) {
+	builder.StartObject(1)
+}
+func AccountDeleteRequestResultAddMethod(builder *flatbuffers.Builder, method flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(method), 0)
+}
+func AccountDeleteRequestResultEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
+	return builder.EndObject()
+}

pkg/fbs/scrabblefb/LinkUnlinkRequest.go

@@ -0,0 +1,60 @@
+// Code generated by the FlatBuffers compiler. DO NOT EDIT.
+
+package scrabblefb
+
+import (
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type LinkUnlinkRequest struct {
+	_tab flatbuffers.Table
+}
+
+func GetRootAsLinkUnlinkRequest(buf []byte, offset flatbuffers.UOffsetT) *LinkUnlinkRequest {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &LinkUnlinkRequest{}
+	x.Init(buf, n+offset)
+	return x
+}
+
+func FinishLinkUnlinkRequestBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.Finish(offset)
+}
+
+func GetSizePrefixedRootAsLinkUnlinkRequest(buf []byte, offset flatbuffers.UOffsetT) *LinkUnlinkRequest {
+	n := flatbuffers.GetUOffsetT(buf[offset+flatbuffers.SizeUint32:])
+	x := &LinkUnlinkRequest{}
+	x.Init(buf, n+offset+flatbuffers.SizeUint32)
+	return x
+}
+
+func FinishSizePrefixedLinkUnlinkRequestBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.FinishSizePrefixed(offset)
+}
+
+func (rcv *LinkUnlinkRequest) Init(buf []byte, i flatbuffers.UOffsetT) {
+	rcv._tab.Bytes = buf
+	rcv._tab.Pos = i
+}
+
+func (rcv *LinkUnlinkRequest) Table() flatbuffers.Table {
+	return rcv._tab
+}
+
+func (rcv *LinkUnlinkRequest) Kind() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(4))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func LinkUnlinkRequestStart(builder *flatbuffers.Builder) {
+	builder.StartObject(1)
+}
+func LinkUnlinkRequestAddKind(builder *flatbuffers.Builder, kind flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(kind), 0)
+}
+func LinkUnlinkRequestEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
+	return builder.EndObject()
+}

pkg/fbs/scrabblefb/LinkVKRequest.go

@@ -0,0 +1,82 @@
+// Code generated by the FlatBuffers compiler. DO NOT EDIT.
+
+package scrabblefb
+
+import (
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type LinkVKRequest struct {
+	_tab flatbuffers.Table
+}
+
+func GetRootAsLinkVKRequest(buf []byte, offset flatbuffers.UOffsetT) *LinkVKRequest {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &LinkVKRequest{}
+	x.Init(buf, n+offset)
+	return x
+}
+
+func FinishLinkVKRequestBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.Finish(offset)
+}
+
+func GetSizePrefixedRootAsLinkVKRequest(buf []byte, offset flatbuffers.UOffsetT) *LinkVKRequest {
+	n := flatbuffers.GetUOffsetT(buf[offset+flatbuffers.SizeUint32:])
+	x := &LinkVKRequest{}
+	x.Init(buf, n+offset+flatbuffers.SizeUint32)
+	return x
+}
+
+func FinishSizePrefixedLinkVKRequestBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.FinishSizePrefixed(offset)
+}
+
+func (rcv *LinkVKRequest) Init(buf []byte, i flatbuffers.UOffsetT) {
+	rcv._tab.Bytes = buf
+	rcv._tab.Pos = i
+}
+
+func (rcv *LinkVKRequest) Table() flatbuffers.Table {
+	return rcv._tab
+}
+
+func (rcv *LinkVKRequest) Code() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(4))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *LinkVKRequest) DeviceId() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(6))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *LinkVKRequest) CodeVerifier() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(8))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func LinkVKRequestStart(builder *flatbuffers.Builder) {
+	builder.StartObject(3)
+}
+func LinkVKRequestAddCode(builder *flatbuffers.Builder, code flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(code), 0)
+}
+func LinkVKRequestAddDeviceId(builder *flatbuffers.Builder, deviceId flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(1, flatbuffers.UOffsetT(deviceId), 0)
+}
+func LinkVKRequestAddCodeVerifier(builder *flatbuffers.Builder, codeVerifier flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(2, flatbuffers.UOffsetT(codeVerifier), 0)
+}
+func LinkVKRequestEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
+	return builder.EndObject()
+}

pkg/fbs/scrabblefb/Profile.go

@@ -179,8 +179,40 @@ func (rcv *Profile) VariantPreferencesLength() int {
 	return 0
 }
 
+func (rcv *Profile) Email() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(30))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *Profile) TelegramLinked() bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(32))
+	if o != 0 {
+		return rcv._tab.GetBool(o + rcv._tab.Pos)
+	}
+	return false
+}
+
+func (rcv *Profile) MutateTelegramLinked(n bool) bool {
+	return rcv._tab.MutateBoolSlot(32, n)
+}
+
+func (rcv *Profile) VkLinked() bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(34))
+	if o != 0 {
+		return rcv._tab.GetBool(o + rcv._tab.Pos)
+	}
+	return false
+}
+
+func (rcv *Profile) MutateVkLinked(n bool) bool {
+	return rcv._tab.MutateBoolSlot(34, n)
+}
+
 func ProfileStart(builder *flatbuffers.Builder) {
-	builder.StartObject(13)
+	builder.StartObject(16)
 }
 func ProfileAddUserId(builder *flatbuffers.Builder, userId flatbuffers.UOffsetT) {
 	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(userId), 0)
@@ -224,6 +256,15 @@ func ProfileAddVariantPreferences(builder *flatbuffers.Builder, variantPreferenc
 func ProfileStartVariantPreferencesVector(builder *flatbuffers.Builder, numElems int) flatbuffers.UOffsetT {
 	return builder.StartVector(4, numElems, 4)
 }
+func ProfileAddEmail(builder *flatbuffers.Builder, email flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(13, flatbuffers.UOffsetT(email), 0)
+}
+func ProfileAddTelegramLinked(builder *flatbuffers.Builder, telegramLinked bool) {
+	builder.PrependBoolSlot(14, telegramLinked, false)
+}
+func ProfileAddVkLinked(builder *flatbuffers.Builder, vkLinked bool) {
+	builder.PrependBoolSlot(15, vkLinked, false)
+}
 func ProfileEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
 	return builder.EndObject()
 }

ui/e2e/maintenance.spec.ts

@@ -0,0 +1,38 @@
+import { expect, test } from './fixtures';
+
+// The maintenance overlay is raised in prod by the edge 503 marker (X-Scrabble-Maintenance);
+// the mock transport never produces one, so — like the offline indicator — the e2e drives it
+// through the window.__maint hook (gateway.ts, mock-only). It is app-global (mounted outside
+// the route blocks in App.svelte), so it shows without a session.
+test('maintenance overlay covers the app and lifts on recovery', async ({ page }) => {
+  await page.goto('/');
+  await expect(page.getByRole('alertdialog')).toHaveCount(0);
+
+  // A planned deploy window begins: a non-dismissable dimmed overlay covers the app.
+  await page.evaluate(() => (window as unknown as { __maint: { on(): void } }).__maint.on());
+  const overlay = page.getByRole('alertdialog');
+  await expect(overlay).toBeVisible();
+  // The retry button is present (EN "Try again" / RU "Повторить" depending on locale).
+  await expect(overlay.getByRole('button', { name: /again|Повторить/i })).toBeVisible();
+
+  // The window ends — in prod the store's poll lifts it on the first successful read; the mock
+  // has no probe, so it clears explicitly. The overlay disappears with no page reload.
+  await page.evaluate(() => (window as unknown as { __maint: { off(): void } }).__maint.off());
+  await expect(page.getByRole('alertdialog')).toHaveCount(0);
+});
+
+test('recovery reloads the SPA to pick up the fresh client', async ({ page }) => {
+  await page.goto('/');
+  await page.evaluate(() => (window as unknown as { __maint: { on(): void } }).__maint.on());
+  await expect(page.getByRole('alertdialog')).toBeVisible();
+
+  // Real recovery reloads the page (the deploy may have shipped an incompatible client, and the
+  // running bundle is the old one). Wait for the forced navigation, then confirm the app
+  // re-bootstrapped: the overlay is gone (the store reset by the reload) and the login is back.
+  await Promise.all([
+    page.waitForEvent('load'),
+    page.evaluate(() => (window as unknown as { __maint: { recover(): void } }).__maint.recover()),
+  ]);
+  await expect(page.getByRole('alertdialog')).toHaveCount(0);
+  await expect(page.getByRole('button', { name: /guest/i })).toBeVisible();
+});

ui/e2e/social.spec.ts

@@ -292,35 +292,73 @@ test('profile edit disables Save and flags an invalid display name', async ({ pa
   await expect(save).toBeEnabled();
 });
 
-// The email upgrade box is now shown to guests (email bind + the merge dialog). These specs
-// still assume a non-guest login and the visible Telegram control, so they stay skipped until
-// PR2 re-enables provider linking and adds a guest-login setup.
-test.skip('link account: a taken email opens the irreversible merge confirmation', async ({ page }) => {
+// The profile's sign-in-methods matrix (email add/change + provider link/unlink). The mock
+// profile is a durable account already holding an email, so the email control is the change
+// flow; a new address containing "taken" stands in (in the mock) for one owned by another
+// account, driving the non-disclosing refusal.
+test('change email: a taken address is refused without disclosure', async ({ page }) => {
   await loginLobby(page);
   await openProfile(page);
 
-  // The email box is shown to guests (this spec needs a guest login — re-enabled in PR2).
-  await expect(page.getByRole('heading', { name: 'Link an account' })).toBeVisible();
-  // An address containing "merge" stands in (in the mock) for one already owned by
-  // another account, so the confirm step reveals a required merge.
-  await page.locator('.emailbox input[type="email"]').fill('merge@example.com');
+  await expect(page.getByText('you@example.com')).toBeVisible();
+  await page.getByRole('button', { name: 'Change' }).click();
+  await page.getByPlaceholder('New email address').fill('taken@example.com');
   await page.getByRole('button', { name: 'Send code' }).click();
-  await page.locator('.emailbox .codein').fill('123456');
+  await page.locator('.accounts .codein').fill('123456');
   await page.getByRole('button', { name: 'OK' }).click();
 
-  // The reveal happens only after the code, and names the other account.
-  await expect(page.getByText('Merge accounts?')).toBeVisible();
-  await expect(page.getByText(/Ann/)).toBeVisible();
-  await page.getByRole('button', { name: 'Merge' }).click();
-  await expect(page.getByText('Merge accounts?')).toBeHidden();
+  // The neutral message never reveals the other account.
+  await expect(page.getByText('Check the address or contact support.')).toBeVisible();
+  await expect(page.getByText(/belongs to another account/)).toHaveCount(0);
+  await expect(page.getByText('you@example.com')).toBeVisible();
 });
 
-test.skip('link account: the Telegram web sign-in control is offered in a browser', async ({ page }) => {
+test('change email: a free address replaces the current one', async ({ page }) => {
   await loginLobby(page);
   await openProfile(page);
+
+  await page.getByRole('button', { name: 'Change' }).click();
+  await page.getByPlaceholder('New email address').fill('fresh@example.com');
+  await page.getByRole('button', { name: 'Send code' }).click();
+  await page.locator('.accounts .codein').fill('123456');
+  await page.getByRole('button', { name: 'OK' }).click();
+
+  await expect(page.getByText('fresh@example.com')).toBeVisible();
+  await expect(page.getByText('you@example.com')).toHaveCount(0);
+});
+
+test('link then unlink Telegram from the sign-in methods', async ({ page }) => {
+  await loginLobby(page);
+  await openProfile(page);
+
+  // On the web the Telegram login-widget control is offered; the mock links it instantly.
+  await page.getByRole('button', { name: 'Link Telegram' }).click();
+  const tgRow = page.locator('.acctrow').filter({ hasText: 'Telegram' });
+  await expect(tgRow).toBeVisible();
+
+  // With email + Telegram two methods remain, so Unlink is offered; confirm it in the dialog.
+  await tgRow.getByRole('button', { name: 'Unlink' }).click();
+  await expect(page.getByText('Unlink account?')).toBeVisible();
+  await page.getByRole('dialog').getByRole('button', { name: 'Unlink' }).click();
+
+  await expect(page.locator('.acctrow').filter({ hasText: 'Telegram' })).toHaveCount(0);
   await expect(page.getByRole('button', { name: 'Link Telegram' })).toBeVisible();
 });
 
+test('account deletion: the mailed-code step-up leads to the terminal deleted screen', async ({ page }) => {
+  await loginLobby(page);
+  await openProfile(page);
+
+  // The mock profile holds an email, so deletion asks for the mailed code.
+  await page.getByRole('button', { name: 'Delete account' }).click();
+  await expect(page.getByText('Delete your account?')).toBeVisible();
+  await page.getByRole('dialog').locator('.codein').fill('123456');
+  await page.getByRole('dialog').getByRole('button', { name: 'Delete permanently' }).click();
+
+  // The app swaps to the terminal account-deleted screen.
+  await expect(page.getByText('Account deleted')).toBeVisible();
+});
+
 test('chat: one message per turn — the field shows, then a caption replaces it after sending', async ({ page }) => {
   await loginLobby(page);
   await page.getByRole('button', { name: /Ann/ }).click(); // g1: your turn

ui/index.html

@@ -2,6 +2,240 @@
 <html lang="ru">
   <head>
     <meta charset="UTF-8" />
+    <!-- Boot capability guard. Runs before the deferred ES module, in plain ES5 so it survives even
+         on an engine too old to parse the bundle. Three jobs, as early as possible:
+           1. Hard gate — if an UNPOLYFILLABLE essential is missing (BigInt for the 64-bit
+              FlatBuffers wire decode, Proxy for Svelte 5 runes) the app cannot run at all: show the
+              unsupported-engine screen (an old Android System WebView, e.g. Chromium 66, is the case
+              this guards) instead of a white screen.
+           2. Soft gate — if only polyfillable es2020+ globals are missing (globalThis,
+              structuredClone, Array.at, …) pull core-js (emitted as polyfills.js) BEFORE the module
+              runs. document.write is deliberate: the only way to inject a parser-blocking <script>
+              guaranteed to run ahead of a deferred module; its argument is a static literal, so no
+              injection surface.
+           3. Reactive net — record any uncaught error/rejection during boot; if the app has not
+              signalled window.__booted within a grace period AND an error fired, show the same
+              screen with the captured cause (covers a bundle that fails to parse, or an unforeseen
+              incompatibility). __booted is set in App.svelte once bootstrap resolves.
+         The screen has a "Diagnostic information" view (engine + feature table + reason + version)
+         with a Copy button. On a capable engine nothing here renders, so neither the bundle-size
+         budget nor the mock e2e is affected. -->
+    <script>
+      (function () {
+        'use strict';
+        var nav = navigator;
+        var ua = nav.userAgent || '';
+        var VERSION = '__BOOT_VERSION__'; // replaced at build (vite.config injectBootVersion)
+        var RU = (nav.language || '').toLowerCase().indexOf('ru') === 0;
+        var MINIAPP = /\/(?:telegram|vk)\//.test(location.pathname);
+        var WEBURL = location.protocol + '//' + location.host + '/app/';
+
+        // [label, test, Chrome version it landed in, hard?] — hard = required and unpolyfillable.
+        function has(fn) {
+          try {
+            return !!fn();
+          } catch (e) {
+            return false;
+          }
+        }
+        var probes = [
+          ['BigInt', function () { return typeof BigInt !== 'undefined'; }, 67, true],
+          ['Proxy', function () { return typeof Proxy !== 'undefined'; }, 49, true],
+          ['globalThis', function () { return typeof globalThis !== 'undefined'; }, 71, false],
+          ['structuredClone', function () { return typeof structuredClone === 'function'; }, 98, false],
+          ['Array.prototype.at', function () { return typeof [].at === 'function'; }, 92, false],
+          ['Array.prototype.findLast', function () { return typeof [].findLast === 'function'; }, 97, false],
+          ['Object.hasOwn', function () { return typeof Object.hasOwn === 'function'; }, 93, false],
+          ['Object.fromEntries', function () { return typeof Object.fromEntries === 'function'; }, 73, false],
+          ['Promise.allSettled', function () { return !!Promise.allSettled; }, 76, false],
+          ['Promise.any', function () { return !!Promise.any; }, 85, false],
+          ['WeakRef', function () { return typeof WeakRef !== 'undefined'; }, 84, false],
+          ['queueMicrotask', function () { return typeof queueMicrotask === 'function'; }, 71, false]
+        ];
+        var results = [];
+        var hardMissing = [];
+        var softMissing = false;
+        for (var i = 0; i < probes.length; i++) {
+          var ok = has(probes[i][1]);
+          results.push({ name: probes[i][0], ok: ok, chrome: probes[i][2], hard: probes[i][3] });
+          if (!ok) {
+            if (probes[i][3]) hardMissing.push(probes[i][0]);
+            else softMissing = true;
+          }
+        }
+
+        // The diagnostic report (built on demand, behind the button).
+        function diag(reason) {
+          var cm = /Chrom(?:e|ium)\/(\d+)/.exec(ua);
+          var wv = /;\s*wv\)/.test(ua) || /\bwv\b/.test(ua);
+          var out = [];
+          out.push('reason    : ' + reason);
+          out.push('app       : ' + VERSION);
+          out.push('chromium  : ' + (cm ? cm[1] : 'n/a') + (wv ? ' (Android WebView)' : ''));
+          out.push('userAgent : ' + ua);
+          out.push('url       : ' + location.href);
+          out.push('viewport  : ' + window.innerWidth + 'x' + window.innerHeight + ' @' + (window.devicePixelRatio || 1));
+          out.push('lang      : ' + (nav.language || '?') + '   online: ' + nav.onLine);
+          out.push('');
+          out.push('features:');
+          for (var k = 0; k < results.length; k++) {
+            var r = results[k];
+            out.push('  ' + (r.ok ? 'OK' : 'NO') + '  ' + r.name + '  (' + (r.hard ? 'required' : 'polyfilled') + ', Chrome ' + r.chrome + ')');
+          }
+          return out.join('\n');
+        }
+
+        function el(tag, style, text) {
+          var e = document.createElement(tag);
+          if (style) e.setAttribute('style', style);
+          if (text != null) e.appendChild(document.createTextNode(text));
+          return e;
+        }
+        function btn(bg, fg) {
+          return 'display:inline-block;margin:0 10px 10px 0;padding:11px 18px;border:0;border-radius:8px;' +
+            'font:600 15px/1 inherit;cursor:pointer;color:' + fg + ';background:' + bg + ';';
+        }
+
+        var shown = false;
+        // Fire-and-forget beacon so the gateway can count who hits this screen (Grafana). Deduped
+        // in localStorage by app version + reason + Chromium, so a user reopening the app ten times
+        // is one report. sendBeacon (Chrome 39+, present on the engines that reach here) with a
+        // fetch fallback; both are best-effort and never block or throw.
+        function beacon(code) {
+          try {
+            var cm = /Chrom(?:e|ium)\/(\d+)/.exec(ua);
+            var chromium = cm ? cm[1] : '';
+            var sig = VERSION + '|' + code + '|' + chromium;
+            try {
+              if (localStorage.getItem('scrabble_unsupp') === sig) return;
+            } catch (e) {}
+            var payload = JSON.stringify({ reason: code, chromium: chromium, version: VERSION, ua: ua });
+            var sent = false;
+            try {
+              if (nav.sendBeacon) sent = nav.sendBeacon('/telemetry/unsupported', new Blob([payload], { type: 'application/json' }));
+            } catch (e) {}
+            if (!sent && typeof fetch === 'function') {
+              try {
+                fetch('/telemetry/unsupported', { method: 'POST', body: payload, headers: { 'Content-Type': 'application/json' }, keepalive: true }).catch(function () {});
+                sent = true;
+              } catch (e) {}
+            }
+            if (sent) {
+              try {
+                localStorage.setItem('scrabble_unsupp', sig);
+              } catch (e) {}
+            }
+          } catch (e) {}
+        }
+        function show(reason, code) {
+          if (shown) return;
+          shown = true;
+          beacon(code);
+          var root = el('div', 'position:fixed;left:0;top:0;right:0;bottom:0;z-index:2147483647;overflow:auto;' +
+            '-webkit-overflow-scrolling:touch;background:#0f1115;color:#e8eaed;box-sizing:border-box;padding:24px;' +
+            'font:16px/1.5 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;');
+          var wrap = el('div', 'max-width:520px;margin:0 auto;');
+          root.appendChild(wrap);
+
+          var msg = el('div', null);
+          msg.appendChild(el('div', 'font-size:22px;font-weight:700;margin-bottom:14px;', 'Эрудит'));
+          msg.appendChild(el('p', 'margin:0 0 14px;', RU
+            ? 'На вашей версии операционной системы или браузера приложение не сможет работать.'
+            : "This app can't run on your device's operating system or browser version."));
+          if (MINIAPP) {
+            msg.appendChild(el('p', 'margin:0 0 6px;', RU
+              ? 'Откройте веб-версию в обычном браузере (Chrome, Firefox):'
+              : 'Open the web version in a regular browser (Chrome, Firefox):'));
+            var a = el('a', 'color:#8ab4ff;word-break:break-all;', WEBURL);
+            a.setAttribute('href', WEBURL);
+            a.setAttribute('target', '_blank');
+            a.setAttribute('rel', 'noopener');
+            var lp = el('p', 'margin:0 0 18px;');
+            lp.appendChild(a);
+            msg.appendChild(lp);
+          }
+          var infoBtn = el('button', btn('#2a2f3a', '#e8eaed'), RU ? 'Диагностическая информация' : 'Diagnostic information');
+          msg.appendChild(infoBtn);
+          wrap.appendChild(msg);
+
+          var dv = el('div', 'display:none;');
+          var pre = el('pre', 'white-space:pre-wrap;word-break:break-word;background:#0b0d11;border-radius:8px;padding:12px;' +
+            'font:12.5px/1.45 ui-monospace,Menlo,Consolas,monospace;overflow:auto;', diag(reason));
+          dv.appendChild(pre);
+          var copyBtn = el('button', btn('#8ab4ff', '#0b0d11'), RU ? 'Копировать' : 'Copy');
+          var backBtn = el('button', btn('#2a2f3a', '#e8eaed'), RU ? 'Назад' : 'Back');
+          var row = el('div', 'margin-top:12px;');
+          row.appendChild(copyBtn);
+          row.appendChild(backBtn);
+          dv.appendChild(row);
+          wrap.appendChild(dv);
+
+          infoBtn.onclick = function () {
+            msg.style.display = 'none';
+            dv.style.display = 'block';
+          };
+          backBtn.onclick = function () {
+            dv.style.display = 'none';
+            msg.style.display = 'block';
+          };
+          copyBtn.onclick = function () {
+            var txt = diag(reason);
+            try {
+              if (nav.clipboard && nav.clipboard.writeText) {
+                nav.clipboard.writeText(txt);
+                copyBtn.firstChild.nodeValue = RU ? 'Скопировано' : 'Copied';
+                return;
+              }
+            } catch (e) {}
+            try {
+              var ta = document.createElement('textarea');
+              ta.value = txt;
+              ta.setAttribute('style', 'position:fixed;left:-9999px;top:0;');
+              document.body.appendChild(ta);
+              ta.select();
+              document.execCommand('copy');
+              document.body.removeChild(ta);
+              copyBtn.firstChild.nodeValue = RU ? 'Скопировано' : 'Copied';
+            } catch (e2) {
+              copyBtn.firstChild.nodeValue = RU ? 'Выделите и скопируйте текст' : 'Select and copy the text';
+            }
+          };
+
+          function mount() {
+            document.body.insertBefore(root, document.body.firstChild);
+          }
+          if (document.body) mount();
+          else document.addEventListener('DOMContentLoaded', mount);
+        }
+
+        // 1 + 2: the gate.
+        if (hardMissing.length) {
+          show((RU ? 'нет: ' : 'missing: ') + hardMissing.join(', '), hardMissing.indexOf('BigInt') >= 0 ? 'no_bigint' : 'no_proxy');
+        } else if (softMissing) {
+          document.write('<script src="polyfills.js"><\/script>');
+        }
+
+        // 3: the reactive net for an unforeseen boot failure.
+        var bootErr = null;
+        function note(m) {
+          if (!bootErr) bootErr = m;
+        }
+        window.onerror = function (m, s, l, c, e) {
+          note(String(m) + (e && e.stack ? '\n' + e.stack : s ? ' @ ' + s + ':' + l : ''));
+          return false;
+        };
+        window.addEventListener('error', function (e) {
+          if (e && e.message) note(e.message + (e.filename ? ' @ ' + e.filename + ':' + e.lineno : ''));
+        }, true);
+        window.addEventListener('unhandledrejection', function (e) {
+          var r = e && e.reason;
+          note(r && (r.stack || r.message) ? r.stack || r.message : String(r));
+        });
+        setTimeout(function () {
+          if (!window.__booted && bootErr && !shown) show((RU ? 'ошибка запуска: ' : 'boot error: ') + bootErr, 'boot_error');
+        }, 8000);
+      })();
+    </script>
     <!-- The SPA shell is an empty client-rendered document behind the public landing — keep it
          out of search indexes (robots.txt deliberately does NOT disallow /app/, so crawlers can
          reach this tag). -->

ui/package.json

@@ -27,6 +27,7 @@
     "@playwright/test": "^1.49.0",
     "@sveltejs/vite-plugin-svelte": "^5.0.0",
     "@types/node": "^22.10.0",
+    "core-js-bundle": "^3.49.0",
     "svelte": "^5.15.0",
     "svelte-check": "^4.1.0",
     "typescript": "^5.7.0",

ui/pnpm-lock.yaml

@@ -36,6 +36,9 @@ importers:
       '@types/node':
         specifier: ^22.10.0
         version: 22.19.19
+      core-js-bundle:
+        specifier: ^3.49.0
+        version: 3.49.0
       svelte:
         specifier: ^5.15.0
         version: 5.56.0
@@ -508,6 +511,9 @@ packages:
     resolution: {integrity: sha512-eYm0QWBtUrBWZWG0d386OGAw16Z995PiOVo2B7bjWSbHedGl5e0ZWaq65kOGgUSNesEIDkB9ISbTg/JK9dhCZA==}
     engines: {node: '>=6'}
 
+  core-js-bundle@3.49.0:
+    resolution: {integrity: sha512-WXc7oOsePN3aKFOJVG5zQdi+h/Jm2W0WIPYvRc4IG3vkNcbC2w6LlSzTmnhOl6N1xmOJEzCSNieX3mwF+3zBGw==}
+
   debug@4.4.3:
     resolution: {integrity: sha512-RGwwWnwQvkVfavKVt22FGLw+xYSdzARwm0ru6DhTVA3umU5hZc28V3kO4stgYryrTlLpuvgI9GiijltAjNbcqA==}
     engines: {node: '>=6.0'}
@@ -1132,6 +1138,8 @@ snapshots:
 
   clsx@2.1.1: {}
 
+  core-js-bundle@3.49.0: {}
+
   debug@4.4.3:
     dependencies:
       ms: 2.1.3

ui/pnpm-workspace.yaml

@@ -1,4 +1,8 @@
 # pnpm 11 records build-script approval here. esbuild's postinstall materialises
 # its CLI shim; the platform binary itself ships as an optional dependency.
+# core-js-bundle ships a prebuilt minified.js (we only read that file at build time,
+# via vite.config emitPolyfills) and its install script is just a funding banner, so
+# it is denied — nothing to build.
 allowBuilds:
+  core-js-bundle: false
   esbuild: true

ui/src/App.svelte

@@ -9,6 +9,7 @@
   import StaleInviteModal from './components/StaleInviteModal.svelte';
   import WelcomeRedeemModal from './components/WelcomeRedeemModal.svelte';
   import Coachmark from './components/Coachmark.svelte';
+  import MaintenanceOverlay from './components/MaintenanceOverlay.svelte';
   import DebugPanel from './components/DebugPanel.svelte';
   import Login from './screens/Login.svelte';
   import Lobby from './screens/Lobby.svelte';
@@ -20,11 +21,17 @@
   import CommsHub from './game/CommsHub.svelte';
   import Feedback from './screens/Feedback.svelte';
   import Blocked from './screens/Blocked.svelte';
+  import AccountDeleted from './screens/AccountDeleted.svelte';
   import BootError from './screens/BootError.svelte';
   import TelegramLaunchError from './screens/TelegramLaunchError.svelte';
 
   onMount(() => {
-    void bootstrap();
+    // Tell the index.html boot guard that startup completed, so its reactive net does not raise the
+    // unsupported-engine screen on a healthy boot — it only fires when an uncaught error occurred
+    // AND this flag never sets (a bundle that failed to parse, or an unforeseen incompatibility).
+    void bootstrap().then(() => {
+      (window as unknown as { __booted?: boolean }).__booted = true;
+    });
   });
 
   // The lobby is the cold-start landing (an empty hash and Telegram launch params both parse
@@ -83,6 +90,8 @@
   <!-- A Mini App launch that failed to authenticate (e.g. the backend was down mid-deploy):
        show the retry screen instead of falling back to the web login. -->
   <BootError />
+{:else if app.accountDeleted}
+  <AccountDeleted />
 {:else if app.blocked}
   <Blocked />
 {:else}
@@ -125,6 +134,7 @@
 <StaleInviteModal />
 <WelcomeRedeemModal />
 <Coachmark />
+<MaintenanceOverlay />
 
 {#if routeIsLobby && !app.splashDone && !app.blocked && !app.bootError && !app.launchError}
   <Splash />

ui/src/components/MaintenanceOverlay.svelte

@@ -0,0 +1,83 @@
+<script lang="ts">
+  // Non-dismissable maintenance cover. Shown while the edge is in a planned deploy window
+  // (maintenance.svelte.ts, raised from a caddy 503 carrying X-Scrabble-Maintenance). It has
+  // no close affordance — an in-session user cannot dismiss it — but the store's poll lifts
+  // it automatically the moment the gateway answers again; the "retry" button just forces an
+  // immediate re-check. Mirrors the static caddy maintenance page (deploy/caddy/maintenance.html)
+  // so a fresh load and an in-session user see the same thing.
+  import { maintenance, retryNow } from '../lib/maintenance.svelte';
+  import { t } from '../lib/i18n/index.svelte';
+</script>
+
+{#if maintenance.active}
+  <div class="scrim" role="alertdialog" aria-modal="true" aria-labelledby="maint-title" aria-describedby="maint-body">
+    <div class="card">
+      <div class="tile" aria-hidden="true">Э</div>
+      <h1 id="maint-title">{t('maintenance.title')}</h1>
+      <p id="maint-body">{t('maintenance.body')}</p>
+      <button type="button" onclick={retryNow}>{t('maintenance.retry')}</button>
+    </div>
+  </div>
+{/if}
+
+<style>
+  .scrim {
+    position: fixed;
+    inset: 0;
+    /* Above the game (z 60) and toasts (z 50) — a planned window covers everything the user
+       could otherwise interact with; below the dev DebugPanel (z 10000). */
+    z-index: 100;
+    background: rgba(0, 0, 0, 0.55);
+    display: grid;
+    place-items: center;
+    padding: 24px;
+    box-sizing: border-box;
+  }
+  .card {
+    max-width: 22rem;
+    text-align: center;
+    background: var(--surface);
+    color: var(--text);
+    border-radius: var(--radius);
+    box-shadow: var(--shadow);
+    padding: 2rem 1.5rem;
+  }
+  /* Mirrors a placed board tile (as Splash.svelte / the caddy page do). */
+  .tile {
+    display: inline-grid;
+    place-items: center;
+    width: 3.5rem;
+    height: 3.5rem;
+    font-size: 2rem;
+    font-weight: 700;
+    border-radius: 4px;
+    background: var(--tile-bg);
+    color: var(--tile-text);
+    box-shadow:
+      inset 0 -2px 0 var(--tile-edge),
+      2px 0 3px -1px rgba(0, 0, 0, 0.4);
+    margin-bottom: 1.25rem;
+  }
+  h1 {
+    font-size: 1.25rem;
+    margin: 0 0 0.5rem;
+  }
+  p {
+    margin: 0 0 1.5rem;
+    color: var(--text-muted);
+    line-height: 1.5;
+  }
+  button {
+    font: inherit;
+    padding: 0.55rem 1.4rem;
+    border: 1px solid var(--border);
+    border-radius: var(--radius);
+    background: transparent;
+    color: var(--text);
+    cursor: pointer;
+  }
+  button:hover {
+    border-color: var(--accent);
+    color: var(--accent);
+  }
+</style>

ui/src/game/Board.svelte

@@ -479,6 +479,11 @@
     position: absolute;
     top: 5%;
     left: 8%;
+    /* Chrome < 105 has no container-query units: a dropped `cqw` would inherit the .cell
+       `font-size: 0` and the glyph would vanish. Fall back to a viewport-relative size that tracks
+       the board (≈ the viewport-fitted query container) and the zoom (--z), so old Android System
+       WebViews still draw the tile glyphs. Chrome 105+ takes the exact `cqw` line below. */
+    font-size: calc(4.2vmin * var(--z, 1));
     font-size: 4.2cqw;
     font-weight: 700;
     line-height: 1;
@@ -487,12 +492,14 @@
     position: absolute;
     right: 5%;
     bottom: 3%;
+    font-size: calc(2.4vmin * var(--z, 1)); /* cqw fallback for Chrome < 105 — see .letter */
     font-size: 2.4cqw;
     font-weight: 600;
   }
   /* A placed Erudit blank ("звёздочка") shows its star where the (absent) point value sits,
      its ink centred on the same line as a neighbouring tile's value digit. */
   .blankmark {
+    font-size: calc(2.8vmin * var(--z, 1)); /* cqw fallback for Chrome < 105 — see .letter */
     font-size: 2.8cqw;
     bottom: 0;
   }
@@ -501,6 +508,7 @@
     inset: 0;
     display: grid;
     place-items: center;
+    font-size: calc(3.6vmin * var(--z, 1)); /* cqw fallback for Chrome < 105 — see .letter */
     font-size: 3.6cqw;
     opacity: 0.7;
   }
@@ -509,6 +517,7 @@
     inset: 0;
     display: grid;
     place-items: center;
+    font-size: calc(2.7vmin * var(--z, 1)); /* cqw fallback for Chrome < 105 — see .letter */
     font-size: 2.7cqw;
     font-weight: 600;
     opacity: 0.9;
@@ -526,10 +535,12 @@
     padding: 0 1px;
   }
   .bt {
+    font-size: calc(1.7vmin * var(--z, 1)); /* cqw fallback for Chrome < 105 — see .letter */
     font-size: 1.7cqw;
     font-weight: 600;
   }
   .bb {
+    font-size: calc(1.9vmin * var(--z, 1)); /* cqw fallback for Chrome < 105 — see .letter */
     font-size: 1.9cqw;
     font-weight: 700;
     white-space: nowrap;

ui/src/gen/fbs/scrabblefb.ts

@@ -1,5 +1,7 @@
 // automatically generated by the FlatBuffers compiler, do not modify
 
+export { AccountDeleteConfirm } from './scrabblefb/account-delete-confirm.js';
+export { AccountDeleteRequestResult } from './scrabblefb/account-delete-request-result.js';
 export { AccountRef } from './scrabblefb/account-ref.js';
 export { Ack } from './scrabblefb/ack.js';
 export { AlphabetEntry } from './scrabblefb/alphabet-entry.js';
@@ -51,6 +53,8 @@ export { LinkEmailConfirm } from './scrabblefb/link-email-confirm.js';
 export { LinkEmailRequest } from './scrabblefb/link-email-request.js';
 export { LinkResult } from './scrabblefb/link-result.js';
 export { LinkTelegramRequest } from './scrabblefb/link-telegram-request.js';
+export { LinkUnlinkRequest } from './scrabblefb/link-unlink-request.js';
+export { LinkVKRequest } from './scrabblefb/link-vkrequest.js';
 export { MatchFoundEvent } from './scrabblefb/match-found-event.js';
 export { MatchResult } from './scrabblefb/match-result.js';
 export { MoveRecord } from './scrabblefb/move-record.js';

ui/src/gen/fbs/scrabblefb/account-delete-confirm.ts

@@ -0,0 +1,60 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+import * as flatbuffers from 'flatbuffers';
+
+export class AccountDeleteConfirm {
+  bb: flatbuffers.ByteBuffer|null = null;
+  bb_pos = 0;
+  __init(i:number, bb:flatbuffers.ByteBuffer):AccountDeleteConfirm {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+}
+
+static getRootAsAccountDeleteConfirm(bb:flatbuffers.ByteBuffer, obj?:AccountDeleteConfirm):AccountDeleteConfirm {
+  return (obj || new AccountDeleteConfirm()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+static getSizePrefixedRootAsAccountDeleteConfirm(bb:flatbuffers.ByteBuffer, obj?:AccountDeleteConfirm):AccountDeleteConfirm {
+  bb.setPosition(bb.position() + flatbuffers.SIZE_PREFIX_LENGTH);
+  return (obj || new AccountDeleteConfirm()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+code():string|null
+code(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+code(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;
+}
+
+phrase():string|null
+phrase(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+phrase(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 startAccountDeleteConfirm(builder:flatbuffers.Builder) {
+  builder.startObject(2);
+}
+
+static addCode(builder:flatbuffers.Builder, codeOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(0, codeOffset, 0);
+}
+
+static addPhrase(builder:flatbuffers.Builder, phraseOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(1, phraseOffset, 0);
+}
+
+static endAccountDeleteConfirm(builder:flatbuffers.Builder):flatbuffers.Offset {
+  const offset = builder.endObject();
+  return offset;
+}
+
+static createAccountDeleteConfirm(builder:flatbuffers.Builder, codeOffset:flatbuffers.Offset, phraseOffset:flatbuffers.Offset):flatbuffers.Offset {
+  AccountDeleteConfirm.startAccountDeleteConfirm(builder);
+  AccountDeleteConfirm.addCode(builder, codeOffset);
+  AccountDeleteConfirm.addPhrase(builder, phraseOffset);
+  return AccountDeleteConfirm.endAccountDeleteConfirm(builder);
+}
+}

ui/src/gen/fbs/scrabblefb/account-delete-request-result.ts

@@ -0,0 +1,48 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+import * as flatbuffers from 'flatbuffers';
+
+export class AccountDeleteRequestResult {
+  bb: flatbuffers.ByteBuffer|null = null;
+  bb_pos = 0;
+  __init(i:number, bb:flatbuffers.ByteBuffer):AccountDeleteRequestResult {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+}
+
+static getRootAsAccountDeleteRequestResult(bb:flatbuffers.ByteBuffer, obj?:AccountDeleteRequestResult):AccountDeleteRequestResult {
+  return (obj || new AccountDeleteRequestResult()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+static getSizePrefixedRootAsAccountDeleteRequestResult(bb:flatbuffers.ByteBuffer, obj?:AccountDeleteRequestResult):AccountDeleteRequestResult {
+  bb.setPosition(bb.position() + flatbuffers.SIZE_PREFIX_LENGTH);
+  return (obj || new AccountDeleteRequestResult()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+method():string|null
+method(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+method(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;
+}
+
+static startAccountDeleteRequestResult(builder:flatbuffers.Builder) {
+  builder.startObject(1);
+}
+
+static addMethod(builder:flatbuffers.Builder, methodOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(0, methodOffset, 0);
+}
+
+static endAccountDeleteRequestResult(builder:flatbuffers.Builder):flatbuffers.Offset {
+  const offset = builder.endObject();
+  return offset;
+}
+
+static createAccountDeleteRequestResult(builder:flatbuffers.Builder, methodOffset:flatbuffers.Offset):flatbuffers.Offset {
+  AccountDeleteRequestResult.startAccountDeleteRequestResult(builder);
+  AccountDeleteRequestResult.addMethod(builder, methodOffset);
+  return AccountDeleteRequestResult.endAccountDeleteRequestResult(builder);
+}
+}

ui/src/gen/fbs/scrabblefb/link-unlink-request.ts

@@ -0,0 +1,48 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+import * as flatbuffers from 'flatbuffers';
+
+export class LinkUnlinkRequest {
+  bb: flatbuffers.ByteBuffer|null = null;
+  bb_pos = 0;
+  __init(i:number, bb:flatbuffers.ByteBuffer):LinkUnlinkRequest {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+}
+
+static getRootAsLinkUnlinkRequest(bb:flatbuffers.ByteBuffer, obj?:LinkUnlinkRequest):LinkUnlinkRequest {
+  return (obj || new LinkUnlinkRequest()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+static getSizePrefixedRootAsLinkUnlinkRequest(bb:flatbuffers.ByteBuffer, obj?:LinkUnlinkRequest):LinkUnlinkRequest {
+  bb.setPosition(bb.position() + flatbuffers.SIZE_PREFIX_LENGTH);
+  return (obj || new LinkUnlinkRequest()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+kind():string|null
+kind(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+kind(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;
+}
+
+static startLinkUnlinkRequest(builder:flatbuffers.Builder) {
+  builder.startObject(1);
+}
+
+static addKind(builder:flatbuffers.Builder, kindOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(0, kindOffset, 0);
+}
+
+static endLinkUnlinkRequest(builder:flatbuffers.Builder):flatbuffers.Offset {
+  const offset = builder.endObject();
+  return offset;
+}
+
+static createLinkUnlinkRequest(builder:flatbuffers.Builder, kindOffset:flatbuffers.Offset):flatbuffers.Offset {
+  LinkUnlinkRequest.startLinkUnlinkRequest(builder);
+  LinkUnlinkRequest.addKind(builder, kindOffset);
+  return LinkUnlinkRequest.endLinkUnlinkRequest(builder);
+}
+}

ui/src/gen/fbs/scrabblefb/link-vkrequest.ts

@@ -0,0 +1,72 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+import * as flatbuffers from 'flatbuffers';
+
+export class LinkVKRequest {
+  bb: flatbuffers.ByteBuffer|null = null;
+  bb_pos = 0;
+  __init(i:number, bb:flatbuffers.ByteBuffer):LinkVKRequest {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+}
+
+static getRootAsLinkVKRequest(bb:flatbuffers.ByteBuffer, obj?:LinkVKRequest):LinkVKRequest {
+  return (obj || new LinkVKRequest()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+static getSizePrefixedRootAsLinkVKRequest(bb:flatbuffers.ByteBuffer, obj?:LinkVKRequest):LinkVKRequest {
+  bb.setPosition(bb.position() + flatbuffers.SIZE_PREFIX_LENGTH);
+  return (obj || new LinkVKRequest()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+code():string|null
+code(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+code(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;
+}
+
+deviceId():string|null
+deviceId(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+deviceId(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;
+}
+
+codeVerifier():string|null
+codeVerifier(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+codeVerifier(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 8);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+static startLinkVKRequest(builder:flatbuffers.Builder) {
+  builder.startObject(3);
+}
+
+static addCode(builder:flatbuffers.Builder, codeOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(0, codeOffset, 0);
+}
+
+static addDeviceId(builder:flatbuffers.Builder, deviceIdOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(1, deviceIdOffset, 0);
+}
+
+static addCodeVerifier(builder:flatbuffers.Builder, codeVerifierOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(2, codeVerifierOffset, 0);
+}
+
+static endLinkVKRequest(builder:flatbuffers.Builder):flatbuffers.Offset {
+  const offset = builder.endObject();
+  return offset;
+}
+
+static createLinkVKRequest(builder:flatbuffers.Builder, codeOffset:flatbuffers.Offset, deviceIdOffset:flatbuffers.Offset, codeVerifierOffset:flatbuffers.Offset):flatbuffers.Offset {
+  LinkVKRequest.startLinkVKRequest(builder);
+  LinkVKRequest.addCode(builder, codeOffset);
+  LinkVKRequest.addDeviceId(builder, deviceIdOffset);
+  LinkVKRequest.addCodeVerifier(builder, codeVerifierOffset);
+  return LinkVKRequest.endLinkVKRequest(builder);
+}
+}

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

@@ -107,8 +107,25 @@ variantPreferencesLength():number {
   return offset ? this.bb!.__vector_len(this.bb_pos + offset) : 0;
 }
 
+email():string|null
+email(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+email(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 30);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+telegramLinked():boolean {
+  const offset = this.bb!.__offset(this.bb_pos, 32);
+  return offset ? !!this.bb!.readInt8(this.bb_pos + offset) : false;
+}
+
+vkLinked():boolean {
+  const offset = this.bb!.__offset(this.bb_pos, 34);
+  return offset ? !!this.bb!.readInt8(this.bb_pos + offset) : false;
+}
+
 static startProfile(builder:flatbuffers.Builder) {
-  builder.startObject(13);
+  builder.startObject(16);
 }
 
 static addUserId(builder:flatbuffers.Builder, userIdOffset:flatbuffers.Offset) {
@@ -175,6 +192,18 @@ static startVariantPreferencesVector(builder:flatbuffers.Builder, numElems:numbe
   builder.startVector(4, numElems, 4);
 }
 
+static addEmail(builder:flatbuffers.Builder, emailOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(13, emailOffset, 0);
+}
+
+static addTelegramLinked(builder:flatbuffers.Builder, telegramLinked:boolean) {
+  builder.addFieldInt8(14, +telegramLinked, +false);
+}
+
+static addVkLinked(builder:flatbuffers.Builder, vkLinked:boolean) {
+  builder.addFieldInt8(15, +vkLinked, +false);
+}
+
 static endProfile(builder:flatbuffers.Builder):flatbuffers.Offset {
   const offset = builder.endObject();
   return offset;