Merge pull request 'Promote development → master (deploy v2: versioning + visible jobs + rollback)' (#106) from development into master

- prod-deploy.yaml is now four visible sequential jobs (build -> deploy-main ->
  deploy-bot -> verify) so the rollout stages show in the Actions UI; the
  per-service rolling stays in the deploy-main log.
- prod-rollback.yaml: a separate manual workflow_dispatch. Leave target_version
  blank to roll back to the previous deployed version (the host now tracks
  DEPLOYED_TAG + PREVIOUS_TAG), or pick a release tag. Re-deploys an already
  published image rolling + health-gated, image-only (no rebuild, no DB migration).
- prod-deploy.sh tracks the previous tag (commit_tag) for the blank-input rollback.
- Docs: ARCHITECTURE §13 + deploy/README runbook cover versioning + rollback.

.gitea/workflows/ci.yaml

@@ -260,11 +260,16 @@ jobs:
           GM_BASICAUTH_HASH: ${{ secrets.TEST_GM_BASICAUTH_HASH }}
           GRAFANA_ADMIN_PASSWORD: ${{ secrets.TEST_GRAFANA_ADMIN_PASSWORD }}
           TELEGRAM_BOT_TOKEN: ${{ secrets.TEST_TELEGRAM_BOT_TOKEN }}
+          TELEGRAM_PROMO_BOT_TOKEN: ${{ secrets.TEST_TELEGRAM_PROMO_BOT_TOKEN }}
           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_GAME_CHANNEL_ID: ${{ vars.TEST_TELEGRAM_GAME_CHANNEL_ID }}
+          TELEGRAM_CHAT_ID: ${{ vars.TEST_TELEGRAM_CHAT_ID }}
+          TELEGRAM_BOT_USERNAME: ${{ vars.TEST_TELEGRAM_BOT_USERNAME }}
+          # The promo button reuses the UI's Mini App link variable.
+          TELEGRAM_BOT_LINK: ${{ vars.TEST_VITE_TELEGRAM_LINK }}
           # The test contour always uses Telegram's test environment — pinned here,
           # not an operator variable. The prod workflow leaves it false.
           TELEGRAM_TEST_ENV: "true"
@@ -296,8 +301,11 @@ jobs:
           # App version for the About screen: the git tag if present, else the short SHA
           # (the test checkout is shallow/untagged, so this is the SHA here — fine).
           export APP_VERSION="$(git -C "$GITHUB_WORKSPACE" describe --tags --always 2>/dev/null || echo dev)"
-          docker compose --ansi never build --progress plain
-          docker compose --ansi never up -d --remove-orphans
+          # The telegram-local profile brings the bot + its VPN sidecar; prod runs the
+          # 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
+          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

.gitea/workflows/prod-deploy.yaml

@@ -0,0 +1,266 @@
+# Manual production rollout. Runs ONLY from master, ONLY on workflow_dispatch with
+# confirm=deploy (development->master is merged + green first; this is the separate,
+# deliberate prod step). Visible sequential jobs from most to least significant:
+#   build -> deploy-main -> deploy-bot -> verify
+# The per-service rolling (postgres->backend->gateway->landing->validator->caddy),
+# health-gating and auto-rollback live in deploy/prod-deploy.sh on the main host and
+# show in the deploy-main log. Manual post-deploy rollback is prod-rollback.yaml.
+# See deploy/README.md (prod runbook).
+name: prod-deploy
+run-name: "prod deploy ${{ github.sha }}"
+
+on:
+  workflow_dispatch:
+    inputs:
+      confirm:
+        description: 'Type "deploy" to confirm a production rollout from master.'
+        required: true
+        default: ""
+
+permissions:
+  contents: read
+
+env:
+  NO_COLOR: "1"
+  DOCKER_CLI_HINTS: "false"
+  REGISTRY: docker.iliadenisov.ru/developer
+
+jobs:
+  build:
+    if: ${{ github.ref == 'refs/heads/master' && inputs.confirm == 'deploy' }}
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        shell: bash
+    outputs:
+      tag: ${{ steps.ver.outputs.tag }}
+    env:
+      PROD_REGISTRY_USER: ${{ vars.PROD_REGISTRY_USER }}
+      PROD_REGISTRY_PASSWORD: ${{ secrets.PROD_REGISTRY_PASSWORD }}
+      VITE_TELEGRAM_BOT_ID: ${{ vars.PROD_VITE_TELEGRAM_BOT_ID }}
+      VITE_TELEGRAM_LINK: ${{ vars.PROD_VITE_TELEGRAM_LINK }}
+      VITE_TELEGRAM_GAME_CHANNEL_NAME: ${{ vars.PROD_VITE_TELEGRAM_GAME_CHANNEL_NAME }}
+      VITE_GATEWAY_URL: ${{ vars.PROD_VITE_GATEWAY_URL }}
+      POSTGRES_PASSWORD: ${{ secrets.PROD_POSTGRES_PASSWORD }}
+      GM_BASICAUTH_HASH: ${{ secrets.PROD_GM_BASICAUTH_HASH }}
+      TELEGRAM_MINIAPP_URL: ${{ vars.PROD_TELEGRAM_MINIAPP_URL }}
+      DICT_VERSION: ${{ vars.PROD_DICT_VERSION }}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Compute version tag
+        id: ver
+        run: echo "tag=$(git describe --tags --always)" >> "$GITHUB_OUTPUT"
+      - name: Registry login
+        run: echo "$PROD_REGISTRY_PASSWORD" | docker login "${REGISTRY%%/*}" -u "$PROD_REGISTRY_USER" --password-stdin
+      - name: Build and push images
+        working-directory: deploy
+        run: |
+          export TAG="${{ steps.ver.outputs.tag }}" APP_VERSION="${{ steps.ver.outputs.tag }}" SCRABBLE_CONFIG_DIR=.
+          # The four main-stack images via compose (reuses the build args, incl. VERSION);
+          # the bot separately, since it is profiled out of the prod compose.
+          docker compose -f docker-compose.yml -f docker-compose.prod.yml build
+          docker compose -f docker-compose.yml -f docker-compose.prod.yml push backend gateway landing validator
+          docker build -f ../platform/telegram/Dockerfile --target bot --build-arg VERSION="$TAG" -t "$REGISTRY/scrabble-telegram-bot:$TAG" ..
+          docker push "$REGISTRY/scrabble-telegram-bot:$TAG"
+
+  deploy-main:
+    needs: build
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        shell: bash
+    env:
+      TAG: ${{ needs.build.outputs.tag }}
+      PROD_REGISTRY_USER: ${{ vars.PROD_REGISTRY_USER }}
+      PROD_REGISTRY_PASSWORD: ${{ secrets.PROD_REGISTRY_PASSWORD }}
+      PROD_SSH_KEY: ${{ secrets.PROD_SSH_KEY }}
+      PROD_SSH_KNOWN_HOSTS: ${{ secrets.PROD_SSH_KNOWN_HOSTS }}
+      MAIN_HOST: ${{ vars.PROD_MAIN_HOST }}
+      POSTGRES_PASSWORD: ${{ secrets.PROD_POSTGRES_PASSWORD }}
+      GM_BASICAUTH_HASH: ${{ secrets.PROD_GM_BASICAUTH_HASH }}
+      GRAFANA_ADMIN_PASSWORD: ${{ secrets.PROD_GRAFANA_ADMIN_PASSWORD }}
+      TELEGRAM_BOT_TOKEN: ${{ secrets.PROD_TELEGRAM_BOT_TOKEN }}
+      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 }}
+      POSTGRES_DB: ${{ vars.PROD_POSTGRES_DB }}
+      POSTGRES_USER: ${{ vars.PROD_POSTGRES_USER }}
+      TELEGRAM_MINIAPP_URL: ${{ vars.PROD_TELEGRAM_MINIAPP_URL }}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Set up SSH
+        run: |
+          mkdir -p ~/.ssh && chmod 700 ~/.ssh
+          printf '%s\n' "$PROD_SSH_KEY" > ~/.ssh/id_deploy && chmod 600 ~/.ssh/id_deploy
+          printf '%s\n' "$PROD_SSH_KNOWN_HOSTS" > ~/.ssh/known_hosts
+      - name: Determine previous tag and migration
+        run: |
+          ssh_main() { ssh -i ~/.ssh/id_deploy -o BatchMode=yes "deploy@$MAIN_HOST" "$@"; }
+          PREV_TAG="$(ssh_main 'cat /opt/scrabble/DEPLOYED_TAG 2>/dev/null || echo none')"
+          MIGRATION=0
+          if [ "$PREV_TAG" != none ]; then
+            if ! git cat-file -e "$PREV_TAG^{commit}" 2>/dev/null; then
+              MIGRATION=1
+            elif git diff --name-only "$PREV_TAG..$TAG" -- backend/internal/postgres/migrations/ | grep -q .; then
+              MIGRATION=1
+            fi
+          fi
+          { echo "PREV_TAG=$PREV_TAG"; echo "MIGRATION=$MIGRATION"; } >> "$GITHUB_ENV"
+          echo "prev=$PREV_TAG migration=$MIGRATION"
+      - name: Render main env + certs
+        run: |
+          umask 077
+          mkdir -p stage/certs-main
+          cat > stage/env.sh <<EOF
+          export REGISTRY='$REGISTRY'
+          export SCRABBLE_CONFIG_DIR='/opt/scrabble'
+          export POSTGRES_DB='${POSTGRES_DB:-scrabble}'
+          export POSTGRES_USER='${POSTGRES_USER:-scrabble}'
+          export POSTGRES_PASSWORD='$POSTGRES_PASSWORD'
+          export GM_BASICAUTH_USER='${GM_BASICAUTH_USER:-gm}'
+          export GM_BASICAUTH_HASH='$GM_BASICAUTH_HASH'
+          export GRAFANA_ADMIN_PASSWORD='$GRAFANA_ADMIN_PASSWORD'
+          export GRAFANA_ROOT_URL='$GRAFANA_ROOT_URL'
+          export CADDY_SITE_ADDRESS='$CADDY_SITE_ADDRESS'
+          export LOG_LEVEL='${LOG_LEVEL:-info}'
+          export DICT_VERSION='$DICT_VERSION'
+          export APP_VERSION='$TAG'
+          export TELEGRAM_BOT_TOKEN='$TELEGRAM_BOT_TOKEN'
+          export TELEGRAM_MINIAPP_URL='$TELEGRAM_MINIAPP_URL'
+          export GATEWAY_ABUSE_BAN_ENABLED='true'
+          EOF
+          printf '%s\n' "$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
+          chmod 644 stage/certs-main/*
+      - name: Deploy the main host
+        run: |
+          ssh_main() { ssh -i ~/.ssh/id_deploy -o BatchMode=yes "deploy@$MAIN_HOST" "$@"; }
+          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 \
+            | 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 -'
+          scp -i ~/.ssh/id_deploy -o BatchMode=yes stage/env.sh "deploy@$MAIN_HOST:/opt/scrabble/env.sh"
+          echo "$PROD_REGISTRY_PASSWORD" | ssh_main "docker login ${REGISTRY%%/*} -u $PROD_REGISTRY_USER --password-stdin"
+          ssh_main "TAG='$TAG' PREV_TAG='$PREV_TAG' MIGRATION='$MIGRATION' bash /opt/scrabble/compose/prod-deploy.sh"
+
+  deploy-bot:
+    needs: [build, deploy-main]
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        shell: bash
+    env:
+      TAG: ${{ needs.build.outputs.tag }}
+      PROD_REGISTRY_USER: ${{ vars.PROD_REGISTRY_USER }}
+      PROD_REGISTRY_PASSWORD: ${{ secrets.PROD_REGISTRY_PASSWORD }}
+      PROD_SSH_KEY: ${{ secrets.PROD_SSH_KEY }}
+      PROD_SSH_KNOWN_HOSTS: ${{ secrets.PROD_SSH_KNOWN_HOSTS }}
+      TG_HOST: ${{ vars.PROD_TG_HOST }}
+      MAIN_HOST: ${{ vars.PROD_MAIN_HOST }}
+      TELEGRAM_BOT_TOKEN: ${{ secrets.PROD_TELEGRAM_BOT_TOKEN }}
+      TELEGRAM_PROMO_BOT_TOKEN: ${{ secrets.PROD_TELEGRAM_PROMO_BOT_TOKEN }}
+      PROD_BOTLINK_CA: ${{ secrets.PROD_BOTLINK_CA }}
+      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 }}
+      TELEGRAM_GAME_CHANNEL_ID: ${{ vars.PROD_TELEGRAM_GAME_CHANNEL_ID }}
+      TELEGRAM_CHAT_ID: ${{ vars.PROD_TELEGRAM_CHAT_ID }}
+      TELEGRAM_BOT_USERNAME: ${{ vars.PROD_TELEGRAM_BOT_USERNAME }}
+      TELEGRAM_BOT_LINK: ${{ vars.PROD_VITE_TELEGRAM_LINK }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up SSH
+        run: |
+          mkdir -p ~/.ssh && chmod 700 ~/.ssh
+          printf '%s\n' "$PROD_SSH_KEY" > ~/.ssh/id_deploy && chmod 600 ~/.ssh/id_deploy
+          printf '%s\n' "$PROD_SSH_KNOWN_HOSTS" > ~/.ssh/known_hosts
+      - name: Render bot env + certs
+        run: |
+          umask 077
+          mkdir -p stage/certs-bot
+          cat > stage/env.bot.sh <<EOF
+          export SCRABBLE_CONFIG_DIR='/opt/scrabble'
+          export BOT_IMAGE='$REGISTRY/scrabble-telegram-bot:$TAG'
+          export BOTLINK_GATEWAY_ADDR='$MAIN_HOST:9443'
+          export TELEGRAM_BOT_TOKEN='$TELEGRAM_BOT_TOKEN'
+          export TELEGRAM_MINIAPP_URL='$TELEGRAM_MINIAPP_URL'
+          export TELEGRAM_GAME_CHANNEL_ID='$TELEGRAM_GAME_CHANNEL_ID'
+          export TELEGRAM_CHAT_ID='$TELEGRAM_CHAT_ID'
+          export TELEGRAM_PROMO_BOT_TOKEN='$TELEGRAM_PROMO_BOT_TOKEN'
+          export TELEGRAM_BOT_USERNAME='$TELEGRAM_BOT_USERNAME'
+          export TELEGRAM_BOT_LINK='$TELEGRAM_BOT_LINK'
+          export LOG_LEVEL='${LOG_LEVEL:-info}'
+          EOF
+          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' "$PROD_BOTLINK_BOT_KEY"  > stage/certs-bot/bot.key
+          chmod 644 stage/certs-bot/*
+      - name: Deploy the bot host
+        run: |
+          ssh_tg() { ssh -i ~/.ssh/id_deploy -o BatchMode=yes "deploy@$TG_HOST" "$@"; }
+          ssh_tg 'mkdir -p /opt/scrabble/compose'
+          tar -C deploy -czf - docker-compose.bot.yml | ssh_tg 'tar -C /opt/scrabble/compose -xzf -'
+          tar -C stage -czf - certs-bot \
+            | ssh_tg 'rm -rf /opt/scrabble/certs && mkdir -p /opt/scrabble/certs && tar -C /opt/scrabble/certs --strip-components=1 -xzf -'
+          scp -i ~/.ssh/id_deploy -o BatchMode=yes stage/env.bot.sh "deploy@$TG_HOST:/opt/scrabble/env.bot.sh"
+          echo "$PROD_REGISTRY_PASSWORD" | ssh_tg "docker login ${REGISTRY%%/*} -u $PROD_REGISTRY_USER --password-stdin"
+          ssh_tg 'set -a; . /opt/scrabble/env.bot.sh; set +a; cd /opt/scrabble/compose;
+            docker compose -f docker-compose.bot.yml pull;
+            docker compose -f docker-compose.bot.yml up -d'
+          ssh_tg 'for i in $(seq 1 20); do
+              s=$(docker inspect -f "{{.State.Status}}" scrabble-telegram-bot 2>/dev/null || echo missing)
+              r=$(docker inspect -f "{{.State.Restarting}}" scrabble-telegram-bot 2>/dev/null || echo true)
+              if [ "$s" = running ] && [ "$r" = false ]; then
+                c1=$(docker inspect -f "{{.RestartCount}}" scrabble-telegram-bot); sleep 5
+                c2=$(docker inspect -f "{{.RestartCount}}" scrabble-telegram-bot)
+                [ "$c1" = "$c2" ] && { echo "bot healthy"; exit 0; }
+              fi
+              sleep 3
+            done
+            echo "bot not healthy:"; docker logs --tail 80 scrabble-telegram-bot; exit 1'
+
+  verify:
+    needs: [deploy-main, deploy-bot]
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        shell: bash
+    env:
+      PROD_SSH_KEY: ${{ secrets.PROD_SSH_KEY }}
+      PROD_SSH_KNOWN_HOSTS: ${{ secrets.PROD_SSH_KNOWN_HOSTS }}
+      MAIN_HOST: ${{ vars.PROD_MAIN_HOST }}
+      CADDY_SITE_ADDRESS: ${{ vars.PROD_CADDY_SITE_ADDRESS }}
+    steps:
+      - name: Set up SSH
+        run: |
+          mkdir -p ~/.ssh && chmod 700 ~/.ssh
+          printf '%s\n' "$PROD_SSH_KEY" > ~/.ssh/id_deploy && chmod 600 ~/.ssh/id_deploy
+          printf '%s\n' "$PROD_SSH_KNOWN_HOSTS" > ~/.ssh/known_hosts
+      - name: Verify the public site
+        run: |
+          domain="${CADDY_SITE_ADDRESS%% *}"
+          ssh -i ~/.ssh/id_deploy -o BatchMode=yes "deploy@$MAIN_HOST" "for i in \$(seq 1 20); do
+              if curl -fsS -k --resolve $domain:443:127.0.0.1 https://$domain/ -o /dev/null &&
+                 curl -fsS -k --resolve $domain:443:127.0.0.1 https://$domain/app/ -o /dev/null &&
+                 docker run --rm --network scrabble-internal alpine:3.20 wget -q -T 5 -O /dev/null http://backend:8080/readyz; then
+                echo 'public site + /app/ + backend healthy'; exit 0
+              fi
+              sleep 5
+            done
+            echo 'public verify failed; recent caddy + gateway + backend logs:'
+            docker logs --tail 40 scrabble-caddy; docker logs --tail 40 scrabble-gateway; docker logs --tail 40 scrabble-backend
+            exit 1"

.gitea/workflows/prod-rollback.yaml

@@ -0,0 +1,223 @@
+# Manual production rollback. Runs ONLY from master, ONLY on workflow_dispatch with
+# confirm=rollback. Re-deploys an already-published image tag (no build): leave
+# target_version blank to roll back to the previously deployed version (read from the
+# main host), or set it to a specific release tag from the Releases page. The
+# re-deploy is the same rolling, health-gated path as prod-deploy (TAG=target,
+# MIGRATION=0 — rollback is image-only and never migrates the DB; image rollback is
+# DB-safe under the expand-contract rule). See deploy/README.md (prod runbook).
+name: prod-rollback
+run-name: "prod rollback ${{ inputs.target_version || 'previous' }}"
+
+on:
+  workflow_dispatch:
+    inputs:
+      confirm:
+        description: 'Type "rollback" to confirm a production rollback.'
+        required: true
+        default: ""
+      target_version:
+        description: "Release tag to roll back to (blank = the previous deployed version)."
+        required: false
+        default: ""
+
+permissions:
+  contents: read
+
+env:
+  NO_COLOR: "1"
+  DOCKER_CLI_HINTS: "false"
+  REGISTRY: docker.iliadenisov.ru/developer
+
+jobs:
+  rollback-main:
+    if: ${{ github.ref == 'refs/heads/master' && inputs.confirm == 'rollback' }}
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        shell: bash
+    outputs:
+      target: ${{ steps.resolve.outputs.target }}
+    env:
+      PROD_REGISTRY_USER: ${{ vars.PROD_REGISTRY_USER }}
+      PROD_REGISTRY_PASSWORD: ${{ secrets.PROD_REGISTRY_PASSWORD }}
+      PROD_SSH_KEY: ${{ secrets.PROD_SSH_KEY }}
+      PROD_SSH_KNOWN_HOSTS: ${{ secrets.PROD_SSH_KNOWN_HOSTS }}
+      MAIN_HOST: ${{ vars.PROD_MAIN_HOST }}
+      POSTGRES_PASSWORD: ${{ secrets.PROD_POSTGRES_PASSWORD }}
+      GM_BASICAUTH_HASH: ${{ secrets.PROD_GM_BASICAUTH_HASH }}
+      GRAFANA_ADMIN_PASSWORD: ${{ secrets.PROD_GRAFANA_ADMIN_PASSWORD }}
+      TELEGRAM_BOT_TOKEN: ${{ secrets.PROD_TELEGRAM_BOT_TOKEN }}
+      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 }}
+      POSTGRES_DB: ${{ vars.PROD_POSTGRES_DB }}
+      POSTGRES_USER: ${{ vars.PROD_POSTGRES_USER }}
+      TELEGRAM_MINIAPP_URL: ${{ vars.PROD_TELEGRAM_MINIAPP_URL }}
+      INPUT_TARGET: ${{ inputs.target_version }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up SSH
+        run: |
+          mkdir -p ~/.ssh && chmod 700 ~/.ssh
+          printf '%s\n' "$PROD_SSH_KEY" > ~/.ssh/id_deploy && chmod 600 ~/.ssh/id_deploy
+          printf '%s\n' "$PROD_SSH_KNOWN_HOSTS" > ~/.ssh/known_hosts
+      - name: Resolve rollback target
+        id: resolve
+        run: |
+          ssh_main() { ssh -i ~/.ssh/id_deploy -o BatchMode=yes "deploy@$MAIN_HOST" "$@"; }
+          CURRENT="$(ssh_main 'cat /opt/scrabble/DEPLOYED_TAG 2>/dev/null || echo none')"
+          if [ -n "$INPUT_TARGET" ]; then
+            TARGET="$INPUT_TARGET"
+          else
+            TARGET="$(ssh_main 'cat /opt/scrabble/PREVIOUS_TAG 2>/dev/null || echo none')"
+          fi
+          if [ -z "$TARGET" ] || [ "$TARGET" = none ]; then
+            echo "no rollback target (no PREVIOUS_TAG on the host and no target_version input)"; exit 1
+          fi
+          if [ "$TARGET" = "$CURRENT" ]; then
+            echo "target $TARGET is already the deployed version; nothing to do"; exit 1
+          fi
+          echo "rolling back: current=$CURRENT -> target=$TARGET"
+          echo "target=$TARGET" >> "$GITHUB_OUTPUT"
+          { echo "TARGET=$TARGET"; echo "CURRENT=$CURRENT"; } >> "$GITHUB_ENV"
+      - name: Render main env + certs
+        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
+          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' "$PROD_BOTLINK_GATEWAY_KEY"  > stage/certs-main/gateway.key
+          chmod 644 stage/certs-main/*
+      - name: Roll the main host back
+        run: |
+          ssh_main() { ssh -i ~/.ssh/id_deploy -o BatchMode=yes "deploy@$MAIN_HOST" "$@"; }
+          ssh_main 'mkdir -p /opt/scrabble/compose'
+          tar -C deploy -czf - docker-compose.yml docker-compose.prod.yml prod-deploy.sh \
+            | ssh_main 'tar -C /opt/scrabble/compose -xzf -'
+          tar -C deploy -czf - caddy otelcol prometheus tempo grafana \
+            | ssh_main 'tar -C /opt/scrabble -xzf -'
+          tar -C stage -czf - certs-main \
+            | ssh_main 'rm -rf /opt/scrabble/certs && mkdir -p /opt/scrabble/certs && tar -C /opt/scrabble/certs --strip-components=1 -xzf -'
+          scp -i ~/.ssh/id_deploy -o BatchMode=yes stage/env.sh "deploy@$MAIN_HOST:/opt/scrabble/env.sh"
+          echo "$PROD_REGISTRY_PASSWORD" | ssh_main "docker login ${REGISTRY%%/*} -u $PROD_REGISTRY_USER --password-stdin"
+          # Image-only rollback: no migration window (TAG=target, MIGRATION=0). A failed
+          # rollback's auto-revert returns to the current version (PREV_TAG=$CURRENT).
+          ssh_main "TAG='$TARGET' PREV_TAG='$CURRENT' MIGRATION=0 bash /opt/scrabble/compose/prod-deploy.sh"
+
+  rollback-bot:
+    needs: rollback-main
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        shell: bash
+    env:
+      TARGET: ${{ needs.rollback-main.outputs.target }}
+      PROD_REGISTRY_USER: ${{ vars.PROD_REGISTRY_USER }}
+      PROD_REGISTRY_PASSWORD: ${{ secrets.PROD_REGISTRY_PASSWORD }}
+      PROD_SSH_KEY: ${{ secrets.PROD_SSH_KEY }}
+      PROD_SSH_KNOWN_HOSTS: ${{ secrets.PROD_SSH_KNOWN_HOSTS }}
+      TG_HOST: ${{ vars.PROD_TG_HOST }}
+      MAIN_HOST: ${{ vars.PROD_MAIN_HOST }}
+      TELEGRAM_BOT_TOKEN: ${{ secrets.PROD_TELEGRAM_BOT_TOKEN }}
+      TELEGRAM_PROMO_BOT_TOKEN: ${{ secrets.PROD_TELEGRAM_PROMO_BOT_TOKEN }}
+      PROD_BOTLINK_CA: ${{ secrets.PROD_BOTLINK_CA }}
+      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 }}
+      TELEGRAM_GAME_CHANNEL_ID: ${{ vars.PROD_TELEGRAM_GAME_CHANNEL_ID }}
+      TELEGRAM_CHAT_ID: ${{ vars.PROD_TELEGRAM_CHAT_ID }}
+      TELEGRAM_BOT_USERNAME: ${{ vars.PROD_TELEGRAM_BOT_USERNAME }}
+      TELEGRAM_BOT_LINK: ${{ vars.PROD_VITE_TELEGRAM_LINK }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up SSH
+        run: |
+          mkdir -p ~/.ssh && chmod 700 ~/.ssh
+          printf '%s\n' "$PROD_SSH_KEY" > ~/.ssh/id_deploy && chmod 600 ~/.ssh/id_deploy
+          printf '%s\n' "$PROD_SSH_KNOWN_HOSTS" > ~/.ssh/known_hosts
+      - name: Render bot env + certs
+        run: |
+          umask 077
+          mkdir -p stage/certs-bot
+          cat > stage/env.bot.sh <<EOF
+          export SCRABBLE_CONFIG_DIR='/opt/scrabble'
+          export BOT_IMAGE='$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
+          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' "$PROD_BOTLINK_BOT_KEY"  > stage/certs-bot/bot.key
+          chmod 644 stage/certs-bot/*
+      - name: Roll the bot host back
+        run: |
+          ssh_tg() { ssh -i ~/.ssh/id_deploy -o BatchMode=yes "deploy@$TG_HOST" "$@"; }
+          ssh_tg 'mkdir -p /opt/scrabble/compose'
+          tar -C deploy -czf - docker-compose.bot.yml | ssh_tg 'tar -C /opt/scrabble/compose -xzf -'
+          tar -C stage -czf - certs-bot \
+            | ssh_tg 'rm -rf /opt/scrabble/certs && mkdir -p /opt/scrabble/certs && tar -C /opt/scrabble/certs --strip-components=1 -xzf -'
+          scp -i ~/.ssh/id_deploy -o BatchMode=yes stage/env.bot.sh "deploy@$TG_HOST:/opt/scrabble/env.bot.sh"
+          echo "$PROD_REGISTRY_PASSWORD" | ssh_tg "docker login ${REGISTRY%%/*} -u $PROD_REGISTRY_USER --password-stdin"
+          ssh_tg 'set -a; . /opt/scrabble/env.bot.sh; set +a; cd /opt/scrabble/compose;
+            docker compose -f docker-compose.bot.yml pull;
+            docker compose -f docker-compose.bot.yml up -d'
+
+  verify:
+    needs: [rollback-main, rollback-bot]
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        shell: bash
+    env:
+      PROD_SSH_KEY: ${{ secrets.PROD_SSH_KEY }}
+      PROD_SSH_KNOWN_HOSTS: ${{ secrets.PROD_SSH_KNOWN_HOSTS }}
+      MAIN_HOST: ${{ vars.PROD_MAIN_HOST }}
+      CADDY_SITE_ADDRESS: ${{ vars.PROD_CADDY_SITE_ADDRESS }}
+    steps:
+      - name: Set up SSH
+        run: |
+          mkdir -p ~/.ssh && chmod 700 ~/.ssh
+          printf '%s\n' "$PROD_SSH_KEY" > ~/.ssh/id_deploy && chmod 600 ~/.ssh/id_deploy
+          printf '%s\n' "$PROD_SSH_KNOWN_HOSTS" > ~/.ssh/known_hosts
+      - name: Verify the public site
+        run: |
+          domain="${CADDY_SITE_ADDRESS%% *}"
+          ssh -i ~/.ssh/id_deploy -o BatchMode=yes "deploy@$MAIN_HOST" "for i in \$(seq 1 20); do
+              if curl -fsS -k --resolve $domain:443:127.0.0.1 https://$domain/ -o /dev/null &&
+                 docker run --rm --network scrabble-internal alpine:3.20 wget -q -T 5 -O /dev/null http://backend:8080/readyz; then
+                echo 'rolled-back site healthy'; exit 0
+              fi
+              sleep 5
+            done
+            echo 'verify failed'; docker logs --tail 40 scrabble-caddy; docker logs --tail 40 scrabble-backend; exit 1"

PLAN.md

@@ -51,7 +51,7 @@ independent (see ARCHITECTURE §9.1).
 | 15 | Dual Telegram bots & language-gated variants | **done** |
 | 16 | Deploy infra & test contour (Dockerfiles, gateway static UI, compose, observability) | **done** |
 | 17 | Test-contour verification & defect fixes | **done** |
-| 18 | Prod contour deploy (SSH export/import, manual after merge) | todo |
+| 18 | Prod contour deploy (registry, two-host, rolling + auto-rollback; manual after merge) | machinery built; first cutover pending DNS |
 | 19 | User feedback (in-app submit + attachment, admin review/reply, account roles) | **done** |
 
 Scaffolding is incremental: `go.work` lists only existing modules; each stage
@@ -413,18 +413,28 @@ raw list is kept here as the record of what the first contour run surfaced.
   "что-то пошло не так". при этом "new -> эрудит" работает. Попробуй посмотреть в логах сейчас, может что-то есть. Или как-то иначе проанализируй, или давай вместе будем смотреть, если не получится.
 
 ### Stage 18 — Prod contour deploy
-Scope: the **production contour** on a remote host over SSH. Deploy by **container export/import**
-(`docker save` → `scp`/ssh → `docker load` → `docker compose up` on the remote), the SSH key + host IP
-in Gitea secrets; **strictly manual** (`workflow_dispatch`) after `development` is merged to `master`
-(the Stage 16 branch model: `feature/* → development → master`, merge gated green). Two-contour config
-uses **`TEST_`/`PROD_` secret/variable prefixes** — Gitea 1.26 has no deployment environments (verified:
-the `environments` API 404s), so a flat prefixed namespace is the convention.
-Reuses the Stage 16 `deploy/docker-compose.yml` as-is, mapping the **`PROD_`** set onto the same
-unprefixed compose vars. **No host caddy on prod**, so the contour's own caddy terminates TLS — set
-`CADDY_SITE_ADDRESS` to the prod domain so caddy does its own ACME (the Caddyfile is already
-parameterised for this; the test contour leaves it `:80` behind the host caddy).
-Open details (re-interview): export/import vs a registry trade-off; prod domain/cert source (ACME vs a
-provided cert) at the contour caddy; prod VPN; rollback.
+Scope: the **production contour** on **two remote hosts** over SSH — main (full stack, `erudit-game.ru`)
+and tg (the bot only). Resolved open details (re-interviewed):
+- **Transport: a registry** (not export/import) — build + push to `docker.iliadenisov.ru`, the hosts pull by tag.
+- **Cert: ACME** at the contour caddy (`CADDY_SITE_ADDRESS=erudit-game.ru www.erudit-game.ru`, no host caddy).
+- **No prod VPN** — the bot host has native Bot API egress (verified `api.telegram.org` → 200).
+- **Rollback** — rolling per-service deploy (least → most dependent), health-gated, auto-rollback to the
+  previous image tag; a maintenance window + consistent `pg_dump` only on a schema migration
+  (expand-contract keeps the auto-rollback image-only; the dump is a manual safety net).
+
+**Strictly manual** (`workflow_dispatch` from `master`, `confirm=deploy`) after `development → master`
+is merged green. `TEST_`/`PROD_` prefixed Gitea secrets/variables (Gitea 1.26 has no deployment
+environments — the `environments` API 404s). Hosts are provisioned by **`deploy/ansible/`** (docker, a
+non-sudo `deploy` user with the CI key, key-only sshd, ufw, fail2ban). The main host is **launch-sized**
+(2 vCPU / 1.9 GiB): `docker-compose.prod.yml` trims the R7 limits (`GOMAXPROCS=2`, smaller caps, 7d
+Prometheus retention) and adds `node_exporter` for host-memory monitoring (launch undersized, resize at
+Selectel reactively). `vpn`+`bot` are gated to a `telegram-local` compose profile (test only); the prod
+bot runs standalone from `docker-compose.bot.yml`. `GATEWAY_ABUSE_BAN_ENABLED=true`.
+
+**Built:** `deploy/ansible/` (both hosts provisioned + verified), the compose split + `node_exporter`,
+`.gitea/workflows/prod-deploy.yaml` + `deploy/prod-deploy.sh`, the full `PROD_` secret/variable set.
+**Remaining (acceptance):** the **first live cutover** — waits on the `erudit-game.ru` DNS delegation
+(`A`/`www` → the main host) that ACME requires; then run the workflow and verify the public site end-to-end.
 
 ### Stage 19 — User feedback *(done)*
 A user→operator feedback channel, sequenced after the numbered stages but shipped **before** the Stage 18

PRERELEASE.md

@@ -39,8 +39,9 @@ the edge before prod. Each phase maps back to the owner's raw pre-release TODO l
 | FM | First-move tile draw (official rules): each seated player draws a tile, the one closest to "A" leads (a blank beats every letter), ties re-drawing until a single leader; **honest per-draw `crypto/rand` entropy**, not the bag seed, so the **record** (`game_setup_draws`, migration `00013`) — not a seed — is the only account of the outcome, kept for future **tournaments** (designed as a discrete per-tile "player N draws" step). Friend/AI draws at create; **auto-match draws at *open*** against a synthetic `uuid.Nil` opponent whose draw rows are back-filled on join, so the opener's seat is fixed up front and the existing open-game pre-move is preserved (no reseating, no play-gating). Admin `/_gm/games/:id` gains the recorded draw list + a simple **step-by-step board replay** (`ReplayTimeline`). | owner ad-hoc | **done** |
 | SB | Single Telegram bot + per-user variant preferences: the two per-language bots collapse into **one** (drop `accounts.service_language`, `supported_languages`, the `*_EN`/`*_RU` env vars and game-language push routing — the single bot renders in the recipient's `preferred_language`); New Game variant gating moves to a profile **`variant_preferences`** set (default Erudit only, Erudit-first, server-enforced on the caller's auto-match/vs-AI/invitation-create paths, an invited friend may accept any variant); env vars collapse to unsuffixed `TELEGRAM_BOT_TOKEN`/`TELEGRAM_GAME_CHANNEL_ID`/`VITE_TELEGRAM_LINK`/`VITE_TELEGRAM_GAME_CHANNEL_NAME` and `GATEWAY_DEFAULT_SUPPORTED_LANGUAGES` is removed; wire drops `service_language`/`supported_languages` (Session, ValidateInitDataResponse) + the push `language` routing field and adds `variant_preferences` to Profile/UpdateProfile. | owner ad-hoc | **done** |
 | DV | Dictionary version hygiene: CI + image/compose seed track the current release (`v1.2.1`); a **seed-drift guard** records the flat dir's seed in an authoritative `.seed_version` marker so a bumped build seed on a live volume is ignored (it can't relabel live bytes — which would mis-serve the dictionary + void games pinned to the prior label); `DICT_VERSION` is the fresh-volume seed only, a live contour migrates through the admin console | owner ad-hoc | **done** |
-| TX | Telegram egress off the main host: split the connector into a home **validator** (Mini App / Login-Widget HMAC, no VPN, no Bot API — so game login no longer depends on Telegram being reachable) and a remote **bot** (Bot API long-poll + `sendMessage`) that holds **no inbound port** and dials the gateway over a reverse **mTLS bot-link** (`pkg/proto/botlink/v1`); the gateway funnels out-of-app push (fire-and-forget, at-most-once) and the backend admin broadcasts (a relay that awaits the bot's ack) down the link. The bot is Telegram-rate-limited; **one bot now**, with seams (a bot registry + `owns_updates` + command ids) for N later; **no webhook** (rejected: one URL per token, adds inbound + a static address). The **unified test contour** runs the split (the bot keeps its VPN sidecar and dials the gateway by its internal name; certs from `deploy/gen-certs.sh`). The **prod** wiring — the bot on a separate host (no VPN), the gateway bot-link port published, `PROD_` certs with scheduled rotation, an SSH deploy of both hosts together — is the **deferred final stage** (Stage 18). | owner ad-hoc | **done** (code + test contour; prod wiring → Stage 18) |
-| AG | Anti-abuse IP ban + honeypot/honeytoken (prod-only): a fail2ban-style in-memory `ratelimit.Banlist` keyed by client IP, fed by sustained rate-limiter rejections (the IP-keyed public/email/admin classes — the user class stays the soft-flag's concern), a **honeypot** decoy path (the contour caddy tags `/.env`, `/.git`, `/wp-*`, … with `X-Scrabble-Honeypot` and routes them to the gateway), and a **honeytoken** (`GATEWAY_HONEYTOKEN`, a planted bearer). The `abuseGuard` edge middleware refuses a banned IP with **429** before any work — closing the R3 gap that the static SPA/landing was outside the token bucket. Off by default — it keys by the real client IP the shared-NAT test contour does not expose (detection still logs there); enabled in prod via `GATEWAY_ABUSE_BAN_ENABLED`. Operators see + lift bans on the console **Throttled** page; the gateway syncs its active set to the backend (`/api/v1/internal/bans/sync`, `internal/banview`) every 30 s and applies operator unbans. | owner ad-hoc | **done** (code + test contour; ban enabled in prod → Stage 18) |
+| TX | Telegram egress off the main host: split the connector into a home **validator** (Mini App / Login-Widget HMAC, no VPN, no Bot API — so game login no longer depends on Telegram being reachable) and a remote **bot** (Bot API long-poll + `sendMessage`) that holds **no inbound port** and dials the gateway over a reverse **mTLS bot-link** (`pkg/proto/botlink/v1`); the gateway funnels out-of-app push (fire-and-forget, at-most-once) and the backend admin broadcasts (a relay that awaits the bot's ack) down the link. The bot is Telegram-rate-limited; **one bot now**, with seams (a bot registry + `owns_updates` + command ids) for N later; **no webhook** (rejected: one URL per token, adds inbound + a static address). The **unified test contour** runs the split (the bot keeps its VPN sidecar and dials the gateway by its internal name; certs from `deploy/gen-certs.sh`). The **prod** wiring — the bot on a separate host (no VPN), the gateway bot-link port published, `PROD_` certs, an SSH deploy of both hosts together — is **built in Stage 18** (the two-host registry rollout; first cutover pending the `erudit-game.ru` DNS). | owner ad-hoc | **done** (code + test contour; prod wiring built — Stage 18) |
+| AG | Anti-abuse IP ban + honeypot/honeytoken (prod-only): a fail2ban-style in-memory `ratelimit.Banlist` keyed by client IP, fed by sustained rate-limiter rejections (the IP-keyed public/email/admin classes — the user class stays the soft-flag's concern), a **honeypot** decoy path (the contour caddy tags `/.env`, `/.git`, `/wp-*`, … with `X-Scrabble-Honeypot` and routes them to the gateway), and a **honeytoken** (`GATEWAY_HONEYTOKEN`, a planted bearer). The `abuseGuard` edge middleware refuses a banned IP with **429** before any work — closing the R3 gap that the static SPA/landing was outside the token bucket. Off by default — it keys by the real client IP the shared-NAT test contour does not expose (detection still logs there); enabled in prod via `GATEWAY_ABUSE_BAN_ENABLED`. Operators see + lift bans on the console **Throttled** page; the gateway syncs its active set to the backend (`/api/v1/internal/bans/sync`, `internal/banview`) every 30 s and applies operator unbans. | owner ad-hoc | **done** (code + test contour; ban on in prod via Stage 18 — machinery built, cutover pending DNS) |
+| CM | Channel-chat moderation + promo bot: a second standalone bot in the bot container answers `/start` with a localized message + a **URL** button into the **main** bot's Mini App (`?startapp`; a `web_app` button would sign initData with the promo token, which the main validator rejects). The **main** bot gates write access in a channel's linked discussion chat. The chat **allows sending by default** and the bot only restricts (Telegram intersects the chat default with the per-user permission, so a per-user grant cannot exceed a deny-by-default group): it **mutes** a member who is not registered or is admin-suspended or holding a new **`chat_muted`** role, and **un-mutes** an eligible one it had muted, for a member currently in the chat (a `getChatMember` guard, since bots cannot list members). Eligibility = `registered AND NOT suspended AND NOT chat_muted` (the game suspension dominates), resolved once in the backend and reached two ways: the bot's `ResolveChatEligibility` on a `chat_member` event over the existing mTLS bot-link, and a backend `chat_access_changed` event → gateway → `ChatGate` command (emitted on block/unblock, a `chat_muted` change, a first registration, or a temporary-block expiry via a sweeper; idempotent). No schema change — `chat_muted` reuses `account_roles`. | owner ad-hoc | **done** |
 | → | Stage 18 — prod contour deploy | — | see [`PLAN.md`](PLAN.md) |
 
 ## Key findings (these reshaped the raw list — read before starting a phase)
@@ -310,7 +311,7 @@ Then Stage 18.
     hammer (99.97 % rejected, p99 2 ms). **Top finding:** ~14 % `transport_error` on `game.state` at 500
     players, under CPU saturation (backend/gateway/Postgres each ~1 core) and amplified by the harness's
     single shared `http2.Transport`; the harness itself peaked at 86 % of a core on the same host, so the
-    figures are pessimistic. Full trip report in [`../loadtest/REPORT-R2.md`](../loadtest/REPORT-R2.md);
+    figures are pessimistic. Full trip report in [`../loadtest/REPORT.md`](../loadtest/REPORT.md);
     it feeds R3 (h2c `MaxConcurrentStreams`/timeouts, body-size cap), R6 and R7 (per-player transports,
     separate hardware, pool/limit sizing).
   - **CI:** `./loadtest/...` added to the path filter + vet/build/test; `go.work.sum` carries the new deps.
@@ -453,7 +454,12 @@ Then Stage 18.
     one connection per player it bursts into its 2-core cap (the residual 2.49 % `transport_error`); backend
     ~0.85 core and postgres ~1.4 cores had headroom; **tempo reached its 1 GiB cap**; the backend pool sat at
     its `MaxOpenConns=25` cap (28 backends); docker logs were unbounded (~14 MiB / 30 min on the backend at
-    info). Full write-up in [`../loadtest/REPORT-R7.md`](../loadtest/REPORT-R7.md).
+    info). Full write-up in [`../loadtest/REPORT.md`](../loadtest/REPORT.md). *(Superseded in part: a
+    later pass modelling the `game.evaluate` hot path traced the gateway's CPU appetite to
+    **gateway→backend connection churn** — the default 2-idle-connection HTTP transport — not proxying
+    work. Pooling the connections cut peak gateway CPU ~7× (~1.75 → ~0.26 cores at 500 players) and
+    removed the ephemeral-port-exhaustion cliff behind the residual `transport_error`, so the gateway is
+    no longer the binding constraint — postgres is. The 3-core gateway cap below is now generous headroom.)*
   - **Round-2 tuning (owner-agreed, all in `deploy/docker-compose.yml`, no code change):** gateway **2 → 3
     cores + `GOMAXPROCS=3`**; tempo memory **1 → 2 GiB**; backend `MAX_OPEN_CONNS` **25 → 40**; a json-file
     **log-rotation** default (10m × 3) applied contour-wide via a YAML anchor (level stays info).
@@ -463,7 +469,7 @@ Then Stage 18.
     **burst** run (a single 100 → 500 jump) pegged the gateway at 3 cores (≈296 % sustained, 9.27 % error),
     confirming it is **connection-CPU-bound** — a true arrival spike is a **horizontal-scaling** lever, not
     more cores per node (recorded in the prod-sizing recommendation).
-  - **No schema change → no contour DB wipe.** Bake-back: `loadtest/REPORT-R7.md` (new), `loadtest/README.md`,
+  - **No schema change → no contour DB wipe.** Bake-back: `loadtest/REPORT.md`, `loadtest/README.md`,
     `docs/TESTING.md`, the telemetry/observability section of `docs/ARCHITECTURE.md`, the repo-layout line in `CLAUDE.md`.
 
 - **UI — Tab-bar navigation redesign** (owner ad-hoc, not on the raw TODO list): drop the hamburger
@@ -579,3 +585,48 @@ Then Stage 18.
     (`game_limit_test.go`: count rule + HTTP gate 409 + accept bypass), server unit (error mapping), gateway
     transcode round-trip, UI codec + lobbycache unit, e2e (`gamelimit.spec.ts`). Bake-back: `docs/FUNCTIONAL.md`
     (+`_ru`), `docs/ARCHITECTURE.md` §8, `docs/UI_DESIGN.md`, `backend/README.md`.
+
+- **CM — Channel-chat moderation + promo bot** (owner ad-hoc, not on the raw TODO list):
+  - **Locked decisions (interview):** the promo bot is a **goroutine in `cmd/bot`** (its own token, no
+    bot-link); the moderated chat's default-no-send is configured by a **human** in the group settings (the
+    bot only grants, never `setChatPermissions`); a non-eligible joiner is **left muted silently**; a
+    temporary-suspension expiry is handled by a **backend sweeper** that emits the re-evaluate event; and a new
+    **`chat_muted` role** is a chat-only mute with the **game suspension dominating**
+    (`eligible = registered AND NOT suspended AND NOT chat_muted`).
+  - **Bot API reality (verified against the docs):** a cross-bot Mini App launch must be a **URL button** to the
+    main bot's `t.me/<bot>?startapp` link — a `web_app` button signs initData with the *sending* bot's token,
+    which the main validator rejects — so the promo button reuses the UI's `VITE_TELEGRAM_LINK`. `chat_member`
+    updates arrive **only** when the bot is a chat **admin** with the "Ban users" right (the client label for the
+    Bot API `can_restrict_members`) and `chat_member` is in `allowed_updates`; bots cannot list members but can
+    `getChatMember` a single user, which is the membership guard on the block/unblock path.
+  - **Wire:** `pkg/proto/botlink/v1` gains a `ChatGateCommand` in the `Command` oneof and a unary
+    `ResolveChatEligibility`; the backend gains `notify.KindChatAccessChanged` (no payload, infra-only — never an
+    out-of-app message) and an internal `POST /api/v1/internal/chat-access` resolver; the gateway resolves the
+    join (by external_id) and the event (by user_id) through it and pushes the chat-gate command fire-and-forget
+    (at-most-once, recovered by the next moderation action or a re-join).
+  - **No schema change → no contour DB wipe:** `chat_muted` is a new `account.KnownRoles` entry (the
+    `account_roles` table is data-driven). The suspension-expiry sweeper is a new `account.SuspensionSweeper`
+    (a 1-minute window, idempotent) started in `cmd/backend`, alongside the guest reaper.
+  - **Deploy:** new `TEST_`/`PROD_` `TELEGRAM_PROMO_BOT_TOKEN` (secret), `TELEGRAM_BOT_USERNAME` and
+    `TELEGRAM_CHAT_ID` (variables); the promo link reuses the existing `*_VITE_TELEGRAM_LINK` variable as
+    `TELEGRAM_BOT_LINK`. The bot must be promoted to admin in the real discussion group, and the group default
+    set to no-send, as part of the Stage 18 prod cutover (the test contour exercises the code path).
+  - **Bake-back:** `docs/ARCHITECTURE.md`, `docs/FUNCTIONAL.md` (+`_ru`), `platform/telegram/README.md`,
+    `backend/README.md`, Go Doc comments. Tests: backend resolver truth table + publish on block/unblock/role +
+    the sweeper window (unit + integration); gateway hub `ResolveChatEligibility` + the chat-gate command; bot
+    `chat_member` grant + `ApplyChatGate` getChatMember-guard; promo `/start` localization + URL button; config
+    parsing.
+  - **Post-contour-test fixes (same PR):** a live test drove three corrections. (1) **Strategy
+    inversion (the key one)** — the original "group default no-send, bot grants the eligible" cannot
+    work: Telegram intersects the chat default with each user's permission, so a per-user grant never
+    exceeds a deny-by-default group (the bot set `can_send=true` yet the user still could not write).
+    The group now **allows sending by default** and the bot only **restricts** — it mutes an ineligible
+    member (unregistered / admin-suspended / `chat_muted`) and un-mutes an eligible one it had muted,
+    acting only when the current state differs (idempotent; the bot's own change is skipped by matching
+    the actor id to the bot). A present member in a default-allow group can appear as `restricted` with
+    `is_member`, so the gate reads both. (2) **Join-before-register** — a user who joins before
+    registering is covered by no `chat_member` event, so `ProvisionTelegram` now reports first contact
+    and the Telegram auth handler emits `chat_access_changed` on it. (3) **Observability** — a startup
+    self-check logs whether the bot is an admin-with-restrict in the chat (it caught a misconfigured
+    `TELEGRAM_CHAT_ID` set to a channel id, not the discussion-group id); the per-event trace is at
+    Debug, the actual mute/unmute and warnings at Info.

backend/Dockerfile

@@ -33,7 +33,9 @@ COPY backend ./backend
 # Reduce the workspace to what the backend needs: backend + pkg. loadtest and the
 # gateway replace it requires are not in this context, so drop both.
 RUN go work edit -dropuse=./gateway -dropuse=./platform/telegram -dropuse=./loadtest -dropreplace=scrabble/gateway@v0.0.0
-RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -o /out/backend ./backend/cmd/backend
+# VERSION (the deploy passes the git tag) is stamped into the binary via the linker.
+ARG VERSION=dev
+RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -ldflags "-X scrabble/pkg/version.Version=${VERSION}" -o /out/backend ./backend/cmd/backend
 
 # --- runtime -----------------------------------------------------------------
 FROM gcr.io/distroless/static-debian12:nonroot

backend/README.md

@@ -106,6 +106,13 @@ Telegram `external_id`, language and `notifications_in_app_only` flag) lets the
 route out-of-app push to the Telegram bot over the gateway bot-link; the Telegram login
 seeds a new account's language and display name from the launch fields, and the
 `accounts.notifications_in_app_only` flag (default true).
+The gateway-only `POST /api/v1/internal/chat-access` resolves a Telegram identity (the
+bot's join-time query) or an account id (a `chat_access_changed` event) to its
+**moderated-chat write eligibility** — `registered AND NOT suspended AND NOT chat_muted`.
+That event is emitted on an admin block/unblock, a `chat_muted` role grant/revoke, or — via
+the `account.SuspensionSweeper` started in `cmd/backend` — a temporary block lapsing;
+`chat_muted` is an `account.KnownRoles` entry, a chat-only mute distinct from the game
+suspension (which dominates it).
 `accounts.is_guest` marks an ephemeral guest — a durable row
 with no identity, excluded from statistics. The server-rendered
 **admin console** at `/_gm` (`internal/adminconsole` + `internal/server/handlers_admin_console.go`;

backend/cmd/backend/main.go

@@ -15,6 +15,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/google/uuid"
 	"go.uber.org/zap"
 
 	"scrabble/backend/internal/account"
@@ -160,6 +161,15 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 		zap.Duration("interval", cfg.GuestReapInterval),
 		zap.Duration("retention", cfg.GuestRetention))
 
+	// 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.
+	chatSweeper := account.NewSuspensionSweeper(accounts, func(id uuid.UUID) {
+		hub.Publish(notify.ChatAccessChanged(id))
+	}, logger)
+	go chatSweeper.Run(ctx)
+	logger.Info("suspension expiry sweeper started", zap.Duration("interval", chatSweeper.Interval()))
+
 	// Lobby & social domains. Their REST and stream surface lives in the gateway,
 	// so they are handed to the server (like the route groups) for the handlers.
 	mailer := newMailer(cfg.SMTP, logger)

backend/internal/account/account.go

@@ -151,14 +151,26 @@ func (s *Store) ProvisionRobot(ctx context.Context, externalID, displayName stri
 	return modelToAccount(row), nil
 }
 
-// ProvisionTelegram provisions (or finds) the account bound to a Telegram
-// identity. On first contact only, it seeds the new account's preferred language
-// from the Telegram client languageCode (when it maps to a supported language) and
-// its display name sanitized from firstName (falling back to username, then to a
-// generated placeholder when neither yields any letters); an already-existing
-// account is returned unchanged, so a later profile edit is never overwritten.
-func (s *Store) ProvisionTelegram(ctx context.Context, externalID, languageCode, username, firstName string) (Account, error) {
-	return s.provision(ctx, KindTelegram, externalID, telegramSeed(languageCode, username, firstName))
+// ProvisionTelegram provisions (or finds) the account bound to a Telegram identity,
+// reporting whether this call created it (first contact). On first contact only, it
+// seeds the new account's preferred language from the Telegram client languageCode
+// (when it maps to a supported language) and its display name sanitized from firstName
+// (falling back to username, then to a generated placeholder when neither yields any
+// letters); an already-existing account is returned unchanged, so a later profile edit
+// is never overwritten. The created flag lets the auth handler re-evaluate moderated-
+// chat write access on first registration — the path of a user who joined the chat
+// before registering, whom no chat_member event covers.
+func (s *Store) ProvisionTelegram(ctx context.Context, externalID, languageCode, username, firstName string) (Account, bool, error) {
+	// Pre-check whether the identity already exists so the caller can act on first
+	// contact. A race with a concurrent create only over- or under-reports created for
+	// that one call, which the idempotent chat-access re-evaluation tolerates.
+	_, err := s.findByIdentity(ctx, KindTelegram, externalID)
+	created := errors.Is(err, ErrNotFound)
+	if err != nil && !created {
+		return Account{}, false, err
+	}
+	acc, err := s.provision(ctx, KindTelegram, externalID, telegramSeed(languageCode, username, firstName))
+	return acc, created, err
 }
 
 // provision finds the account for (kind, externalID) or creates it with seed,
@@ -303,6 +315,14 @@ func (s *Store) CountAccounts(ctx context.Context) (int, error) {
 	return int(dest.Count), nil
 }
 
+// AccountByIdentity returns the account bound to (kind, externalID), or ErrNotFound
+// when none exists. Unlike ProvisionByIdentity it never creates one: the chat-access
+// resolver uses it to tell a registered Telegram user (eligible to be granted chat
+// write access) from an unregistered one (left muted).
+func (s *Store) AccountByIdentity(ctx context.Context, kind, externalID string) (Account, error) {
+	return s.findByIdentity(ctx, kind, externalID)
+}
+
 // findByIdentity joins identities to accounts and returns the matching account,
 // or ErrNotFound.
 func (s *Store) findByIdentity(ctx context.Context, kind, externalID string) (Account, error) {

backend/internal/account/roles.go

@@ -24,11 +24,19 @@ const (
 	// unconditionally, overriding the usual eligibility (a free account with an
 	// empty hint wallet otherwise sees it). See internal/ads.
 	RoleNoBanner = "no_banner"
+
+	// RoleChatMuted forbids the account from writing in the moderated Telegram
+	// discussion chat, without otherwise restricting the game (the chat-only
+	// counterpart to a full account suspension). It is one input to the chat-access
+	// gate; an active admin suspension mutes the player regardless, so this role only
+	// matters for an account that is not suspended. Granting or revoking it re-pushes
+	// the chat-gate command for a member currently in the chat.
+	RoleChatMuted = "chat_muted"
 )
 
 // KnownRoles is the set of roles the console may grant or revoke; an operator
 // cannot assign an unrecognised role.
-var KnownRoles = []string{RoleFeedbackBanned, RoleNoBanner}
+var KnownRoles = []string{RoleFeedbackBanned, RoleNoBanner, RoleChatMuted}
 
 // IsKnownRole reports whether role is a recognised account role.
 func IsKnownRole(role string) bool {

backend/internal/account/suspension.go

@@ -161,6 +161,31 @@ func (s *Store) queryCurrentSuspension(ctx context.Context, accountID uuid.UUID,
 	return modelToSuspension(row), true, nil
 }
 
+// SuspensionsExpiredBetween returns the distinct account ids whose temporary block lapsed in the
+// half-open window (since, until]: a non-lifted suspension with a blocked_until in that range. The
+// chat-access sweeper uses it to re-evaluate chat write access when a temporary block self-expires,
+// since no operator action fires then. An account that still has another active block may be
+// included; the eligibility resolver returns the true state, so emitting for it is harmless.
+func (s *Store) SuspensionsExpiredBetween(ctx context.Context, since, until time.Time) ([]uuid.UUID, error) {
+	rows, err := s.db.QueryContext(ctx,
+		`SELECT DISTINCT account_id FROM backend.account_suspensions
+		 WHERE lifted_at IS NULL AND blocked_until > $1 AND blocked_until <= $2`,
+		since.UTC(), until.UTC())
+	if err != nil {
+		return nil, fmt.Errorf("account: suspensions expired between: %w", err)
+	}
+	defer rows.Close()
+	var out []uuid.UUID
+	for rows.Next() {
+		var id uuid.UUID
+		if err := rows.Scan(&id); err != nil {
+			return nil, fmt.Errorf("account: scan expired suspension: %w", err)
+		}
+		out = append(out, id)
+	}
+	return out, rows.Err()
+}
+
 // invalidateSuspension drops the account's cached block so the next CurrentSuspension re-reads it.
 // Called after Suspend and LiftSuspension.
 func (s *Store) invalidateSuspension(accountID uuid.UUID) {

backend/internal/account/suspension_sweeper.go

@@ -0,0 +1,84 @@
+package account
+
+import (
+	"context"
+	"time"
+
+	"github.com/google/uuid"
+	"go.uber.org/zap"
+)
+
+// suspensionSweepInterval is how often the sweeper re-checks for temporary blocks
+// that lapsed. A minute is well under the coarsest block grain (operators pick day
+// presets) while keeping the query trivial.
+const suspensionSweepInterval = time.Minute
+
+// suspensionExpiryQuerier is the slice of the account store the sweeper depends on:
+// the accounts whose temporary block lapsed in a window. *Store satisfies it; a fake
+// drives the sweeper's unit tests.
+type suspensionExpiryQuerier interface {
+	SuspensionsExpiredBetween(ctx context.Context, since, until time.Time) ([]uuid.UUID, error)
+}
+
+// SuspensionSweeper re-evaluates chat write access when a temporary block self-
+// expires. No operator action fires on expiry — the suspension gate just re-reads
+// the wall clock — so without this a temporarily blocked player would stay muted in
+// the moderated discussion chat after their block lapsed. Each tick it finds blocks
+// that expired since the previous tick and calls onExpire for the affected accounts;
+// onExpire is wired to publish the chat-access-changed event, after which the gateway
+// re-resolves the true eligibility. A liberal call (an account that still has another
+// active block) is therefore harmless. The window is in-memory, so a block that
+// expires while the process is down is not re-granted until the next operator action
+// or the player rejoins — an accepted best-effort gap.
+type SuspensionSweeper struct {
+	store    suspensionExpiryQuerier
+	onExpire func(accountID uuid.UUID)
+	log      *zap.Logger
+	// since is the upper bound of the previous swept window; the next sweep covers
+	// (since, now]. It advances only on a successful query, so a failed tick retries
+	// the same window rather than dropping expiries.
+	since time.Time
+}
+
+// NewSuspensionSweeper builds the sweeper over the account store, the per-account
+// expiry callback (publishing the chat-access-changed event) and a logger. The first
+// window opens at construction time, so blocks that lapsed earlier are not re-emitted.
+func NewSuspensionSweeper(store *Store, onExpire func(accountID uuid.UUID), log *zap.Logger) *SuspensionSweeper {
+	if log == nil {
+		log = zap.NewNop()
+	}
+	return &SuspensionSweeper{store: store, onExpire: onExpire, log: log, since: time.Now().UTC()}
+}
+
+// Interval reports the sweep cadence, for the startup log line.
+func (w *SuspensionSweeper) Interval() time.Duration { return suspensionSweepInterval }
+
+// Run sweeps every Interval until ctx is cancelled.
+func (w *SuspensionSweeper) Run(ctx context.Context) {
+	ticker := time.NewTicker(suspensionSweepInterval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			w.sweep(ctx)
+		}
+	}
+}
+
+// sweep emits a chat-access-changed signal for every account whose temporary block
+// lapsed in (since, now], then advances the window. On a query error it keeps the
+// window so the next tick retries it.
+func (w *SuspensionSweeper) sweep(ctx context.Context) {
+	now := time.Now().UTC()
+	ids, err := w.store.SuspensionsExpiredBetween(ctx, w.since, now)
+	if err != nil {
+		w.log.Warn("suspension expiry sweep failed", zap.Error(err))
+		return
+	}
+	w.since = now
+	for _, id := range ids {
+		w.onExpire(id)
+	}
+}

backend/internal/account/suspension_sweeper_test.go

@@ -0,0 +1,80 @@
+package account
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/zap"
+)
+
+// fakeExpiryQuerier records the `since` bound of each call and replays a scripted
+// result/error per call, so the sweeper's window and dispatch logic is testable
+// without a database.
+type fakeExpiryQuerier struct {
+	results [][]uuid.UUID
+	errs    []error
+	sinces  []time.Time
+	idx     int
+}
+
+func (f *fakeExpiryQuerier) SuspensionsExpiredBetween(_ context.Context, since, _ time.Time) ([]uuid.UUID, error) {
+	f.sinces = append(f.sinces, since)
+	i := f.idx
+	f.idx++
+	if i < len(f.errs) && f.errs[i] != nil {
+		return nil, f.errs[i]
+	}
+	if i < len(f.results) {
+		return f.results[i], nil
+	}
+	return nil, nil
+}
+
+func newSweeper(store suspensionExpiryQuerier, onExpire func(uuid.UUID)) *SuspensionSweeper {
+	return &SuspensionSweeper{
+		store:    store,
+		onExpire: onExpire,
+		log:      zap.NewNop(),
+		since:    time.Now().Add(-time.Minute).UTC(),
+	}
+}
+
+func TestSuspensionSweeperDispatchesAndAdvances(t *testing.T) {
+	id1, id2 := uuid.New(), uuid.New()
+	fake := &fakeExpiryQuerier{results: [][]uuid.UUID{{id1, id2}, nil}}
+	var got []uuid.UUID
+	w := newSweeper(fake, func(id uuid.UUID) { got = append(got, id) })
+
+	first := w.since
+	w.sweep(context.Background())
+	assert.Equal(t, []uuid.UUID{id1, id2}, got, "every expired account is dispatched")
+	assert.True(t, w.since.After(first), "the window advances on success")
+
+	// A second sweep opens the next window at the previous upper bound.
+	prev := w.since
+	w.sweep(context.Background())
+	require.Len(t, fake.sinces, 2)
+	assert.True(t, fake.sinces[1].After(fake.sinces[0]), "consecutive windows are contiguous and forward")
+	assert.True(t, fake.sinces[1].Equal(prev), "the next window starts at the previous upper bound")
+}
+
+func TestSuspensionSweeperKeepsWindowOnError(t *testing.T) {
+	fake := &fakeExpiryQuerier{errs: []error{errors.New("db down")}}
+	w := newSweeper(fake, func(uuid.UUID) { t.Fatal("onExpire must not run when the query fails") })
+
+	before := w.since
+	w.sweep(context.Background())
+	assert.True(t, w.since.Equal(before), "the window is retained on error so the next tick retries it")
+}
+
+func TestNewSuspensionSweeperDefaults(t *testing.T) {
+	w := NewSuspensionSweeper(nil, func(uuid.UUID) {}, nil)
+	assert.Equal(t, time.Minute, w.Interval())
+	assert.NotNil(t, w.log, "a nil logger is tolerated")
+	assert.WithinDuration(t, time.Now().UTC(), w.since, time.Second, "the first window opens at construction time")
+}

backend/internal/game/cache.go

@@ -63,6 +63,7 @@ type gameCache struct {
 
 type cachedGame struct {
 	game       *engine.Game
+	seats      []Seat
 	variant    string
 	lastAccess time.Time
 }
@@ -71,24 +72,27 @@ func newGameCache(ttl time.Duration, now func() time.Time) *gameCache {
 	return &gameCache{entries: make(map[uuid.UUID]*cachedGame), ttl: ttl, now: now}
 }
 
-// get returns the live game for id and refreshes its idle timer, or (nil, false).
-func (c *gameCache) get(id uuid.UUID) (*engine.Game, bool) {
+// get returns the live game and its immutable seat list for id and refreshes its idle
+// timer, or (nil, nil, false). The seats let a read check membership (and label seats)
+// without re-loading the game from the store, since seats never change after a game starts.
+func (c *gameCache) get(id uuid.UUID) (*engine.Game, []Seat, bool) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	e, ok := c.entries[id]
 	if !ok {
-		return nil, false
+		return nil, nil, false
 	}
 	e.lastAccess = c.now()
-	return e.game, true
+	return e.game, e.seats, true
 }
 
-// put stores g as the live game for id. variant labels the entry so the active-
-// games gauge can report counts by variant without inspecting engine internals.
-func (c *gameCache) put(id uuid.UUID, g *engine.Game, variant string) {
+// put stores g as the live game for id together with its seat list. variant labels the
+// entry so the active-games gauge can report counts by variant without inspecting engine
+// internals; seats are the game's immutable seat standings for the membership fast path.
+func (c *gameCache) put(id uuid.UUID, g *engine.Game, variant string, seats []Seat) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
-	c.entries[id] = &cachedGame{game: g, variant: variant, lastAccess: c.now()}
+	c.entries[id] = &cachedGame{game: g, seats: seats, variant: variant, lastAccess: c.now()}
 }
 
 // remove drops id from the cache (used on a finished game and after a failed

backend/internal/game/helpers_test.go

@@ -94,8 +94,8 @@ func TestGameCacheEviction(t *testing.T) {
 	cur := time.Unix(1_700_000_000, 0)
 	cache := newGameCache(time.Hour, func() time.Time { return cur })
 	id := uuid.New()
-	cache.put(id, nil, "scrabble_en")
-	if _, ok := cache.get(id); !ok {
+	cache.put(id, nil, "scrabble_en", nil)
+	if _, _, ok := cache.get(id); !ok {
 		t.Fatal("game must be resident after put")
 	}
 	cur = cur.Add(30 * time.Minute)
@@ -104,7 +104,7 @@ func TestGameCacheEviction(t *testing.T) {
 	if n := cache.sweep(); n != 1 {
 		t.Errorf("sweep evicted %d, want 1", n)
 	}
-	if _, ok := cache.get(id); ok {
+	if _, _, ok := cache.get(id); ok {
 		t.Error("game must be evicted after idle TTL")
 	}
 	if cache.size() != 0 {

backend/internal/game/service.go

@@ -287,12 +287,12 @@ func (svc *Service) Create(ctx context.Context, params CreateParams) (Game, erro
 	if err := svc.store.CreateGame(ctx, ins, seats, seeding.draws); err != nil {
 		return Game{}, err
 	}
-	svc.cache.put(id, g, params.Variant.String())
 	svc.metrics.recordStarted(ctx, params.Variant, params.VsAI)
 	created, err := svc.store.GetGame(ctx, id)
 	if err != nil {
 		return Game{}, err
 	}
+	svc.cache.put(id, g, params.Variant.String(), created.Seats)
 	// Honest-AI game seated with a robot: if the robot moves first, reply at once
 	// (the periodic driver is the fallback). No-op for every human-only game.
 	svc.triggerAI(created)
@@ -890,26 +890,35 @@ func (svc *Service) timeoutGame(ctx context.Context, gameID uuid.UUID, now time.
 // EvaluatePlay previews a tentative play for a seated player against the current
 // board without committing it: whether it is legal and what it would score.
 func (svc *Service) EvaluatePlay(ctx context.Context, gameID, accountID uuid.UUID, tiles []engine.TileRecord) (EvalResult, error) {
+	unlock := svc.locks.lock(gameID)
+	defer unlock()
+
+	// Hot path: an active game stays cached — the engine game is mutated in place across
+	// moves and evicted only when it finishes — so on a hit the cached live game and its
+	// immutable seat list answer the membership check and the score with no DB read. This
+	// preview is fired on every tile placement, the hottest gameplay call at scale.
+	g, seats, ok := svc.cache.get(gameID)
+	if !ok {
+		// Cold path: load and validate from the store, then replay into the cache.
 		pre, err := svc.store.GetGame(ctx, gameID)
 		if err != nil {
 			return EvalResult{}, err
 		}
-	if _, ok := pre.seatOf(accountID); !ok {
-		return EvalResult{}, ErrNotAPlayer
-	}
 		if pre.Status == StatusFinished {
 			return EvalResult{}, ErrFinished
 		}
-
-	unlock := svc.locks.lock(gameID)
-	defer unlock()
-	g, err := svc.liveGame(ctx, pre)
-	if err != nil {
+		if g, err = svc.liveGame(ctx, pre); err != nil {
 			return EvalResult{}, err
 		}
+		seats = pre.Seats
+	}
+	if !seatedIn(seats, accountID) {
+		return EvalResult{}, ErrNotAPlayer
+	}
+
 	validateStart := time.Now()
 	rec, err := g.EvaluatePlay(tiles)
-	svc.metrics.recordValidate(ctx, pre.Variant, validateStart)
+	svc.metrics.recordValidate(ctx, g.Variant(), validateStart)
 	if err != nil {
 		if errors.Is(err, engine.ErrIllegalPlay) {
 			return EvalResult{Valid: false}, nil
@@ -1359,7 +1368,7 @@ func (svc *Service) ExportGCG(ctx context.Context, gameID uuid.UUID) (string, er
 // liveGame returns the live engine.Game for pre, rebuilding it from the journal
 // on a cache miss. Callers must hold the per-game lock.
 func (svc *Service) liveGame(ctx context.Context, pre Game) (*engine.Game, error) {
-	if g, ok := svc.cache.get(pre.ID); ok {
+	if g, _, ok := svc.cache.get(pre.ID); ok {
 		return g, nil
 	}
 	g, err := svc.replay(ctx, pre)
@@ -1374,7 +1383,7 @@ func (svc *Service) liveGame(ctx context.Context, pre Game) (*engine.Game, error
 		}
 	}
 	if !g.Over() {
-		svc.cache.put(pre.ID, g, pre.Variant.String())
+		svc.cache.put(pre.ID, g, pre.Variant.String(), pre.Seats)
 	}
 	return g, nil
 }

backend/internal/game/store.go

@@ -355,27 +355,33 @@ func (s *Store) ExpiredOpen(ctx context.Context, now time.Time) ([]OpenGame, err
 // GetGame loads the games row joined with its seats (ordered by seat), or
 // ErrNotFound.
 func (s *Store) GetGame(ctx context.Context, id uuid.UUID) (Game, error) {
-	gstmt := postgres.SELECT(table.Games.AllColumns).
-		FROM(table.Games).
+	// One round-trip: the game joined with its seats. A LEFT JOIN keeps a (would-be)
+	// seatless game returning the game with no seats, exactly as the prior two-query
+	// version did; ORDER BY seat preserves seat order. The games columns repeat per seat
+	// row — cheap at 2-4 seats, and one round-trip instead of two, which matters because
+	// GetGame is the universal "load the game" step on every game operation.
+	stmt := postgres.SELECT(table.Games.AllColumns, table.GamePlayers.AllColumns).
+		FROM(table.Games.LEFT_JOIN(table.GamePlayers, table.GamePlayers.GameID.EQ(table.Games.GameID))).
 		WHERE(table.Games.GameID.EQ(postgres.UUID(id))).
-		LIMIT(1)
-	var grow model.Games
-	if err := gstmt.QueryContext(ctx, s.db, &grow); err != nil {
-		if errors.Is(err, qrm.ErrNoRows) {
-			return Game{}, ErrNotFound
+		ORDER_BY(table.GamePlayers.Seat.ASC())
+	var rows []struct {
+		model.Games
+		model.GamePlayers
 	}
+	if err := stmt.QueryContext(ctx, s.db, &rows); err != nil {
 		return Game{}, fmt.Errorf("game: get %s: %w", id, err)
 	}
-
-	sstmt := postgres.SELECT(table.GamePlayers.AllColumns).
-		FROM(table.GamePlayers).
-		WHERE(table.GamePlayers.GameID.EQ(postgres.UUID(id))).
-		ORDER_BY(table.GamePlayers.Seat.ASC())
-	var srows []model.GamePlayers
-	if err := sstmt.QueryContext(ctx, s.db, &srows); err != nil {
-		return Game{}, fmt.Errorf("game: get seats %s: %w", id, err)
+	if len(rows) == 0 {
+		return Game{}, ErrNotFound
 	}
-	return projectGame(grow, srows)
+	seats := make([]model.GamePlayers, 0, len(rows))
+	for i := range rows {
+		// Skip the phantom all-NULL seat row a LEFT JOIN yields for a seatless game.
+		if rows[i].GamePlayers.GameID == id {
+			seats = append(seats, rows[i].GamePlayers)
+		}
+	}
+	return projectGame(rows[0].Games, seats)
 }
 
 // GetGameVariant reads just a game's variant — a cheap single-column lookup the edge uses

backend/internal/game/types.go

@@ -184,6 +184,18 @@ func (g Game) seatOf(accountID uuid.UUID) (int, bool) {
 	return 0, false
 }
 
+// seatedIn reports whether accountID holds a seat in seats. It backs the read-side
+// membership check against the cached, immutable seat list, so a hot read can skip
+// loading the game from the store.
+func seatedIn(seats []Seat, accountID uuid.UUID) bool {
+	for _, s := range seats {
+		if s.AccountID == accountID {
+			return true
+		}
+	}
+	return false
+}
+
 // MoveResult is the outcome of a committed transition: the decoded move and the
 // post-move game, plus the actor's own refilled rack and the bag size after the draw
 // (Rack/BagLen), so the mover renders the next state from the response without a

backend/internal/inttest/account_test.go

@@ -118,10 +118,13 @@ func TestProvisionTelegramSeedsNewAccountOnly(t *testing.T) {
 	store := account.NewStore(testDB)
 	ext := "tg-" + uuid.NewString()
 
-	acc, err := store.ProvisionTelegram(ctx, ext, "ru-RU", "thehandle", "Иван")
+	acc, created, err := store.ProvisionTelegram(ctx, ext, "ru-RU", "thehandle", "Иван")
 	if err != nil {
 		t.Fatalf("provision telegram: %v", err)
 	}
+	if !created {
+		t.Error("created = false on first contact, want true")
+	}
 	if acc.PreferredLanguage != "ru" {
 		t.Errorf("PreferredLanguage = %q, want ru", acc.PreferredLanguage)
 	}
@@ -133,10 +136,13 @@ func TestProvisionTelegramSeedsNewAccountOnly(t *testing.T) {
 	}
 
 	// A later login with different fields returns the same account, unchanged.
-	again, err := store.ProvisionTelegram(ctx, ext, "en", "other", "Other")
+	again, created, err := store.ProvisionTelegram(ctx, ext, "en", "other", "Other")
 	if err != nil {
 		t.Fatalf("re-provision telegram: %v", err)
 	}
+	if created {
+		t.Error("created = true on a repeat login, want false")
+	}
 	if again.ID != acc.ID {
 		t.Errorf("re-provision id = %s, want %s", again.ID, acc.ID)
 	}
@@ -150,7 +156,7 @@ func TestProvisionTelegramSeedsNewAccountOnly(t *testing.T) {
 // language CHECK.
 func TestProvisionTelegramUnknownLanguageDefaults(t *testing.T) {
 	ctx := context.Background()
-	acc, err := account.NewStore(testDB).ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "fr", "", "")
+	acc, _, err := account.NewStore(testDB).ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "fr", "", "")
 	if err != nil {
 		t.Fatalf("provision telegram: %v", err)
 	}
@@ -166,7 +172,7 @@ func TestProvisionTelegramUnknownLanguageDefaults(t *testing.T) {
 func TestHighRateFlagRoundTrip(t *testing.T) {
 	ctx := context.Background()
 	store := account.NewStore(testDB)
-	acc, err := store.ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "en", "", "Player")
+	acc, _, err := store.ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "en", "", "Player")
 	if err != nil {
 		t.Fatalf("provision telegram: %v", err)
 	}
@@ -222,7 +228,7 @@ func TestIdentityExternalID(t *testing.T) {
 	ctx := context.Background()
 	store := account.NewStore(testDB)
 	ext := "tg-" + uuid.NewString()
-	acc, err := store.ProvisionTelegram(ctx, ext, "en", "", "Tg User")
+	acc, _, err := store.ProvisionTelegram(ctx, ext, "en", "", "Tg User")
 	if err != nil {
 		t.Fatalf("provision telegram: %v", err)
 	}
@@ -247,7 +253,7 @@ func TestIdentityExternalID(t *testing.T) {
 func TestNotificationsInAppOnlyRoundTrip(t *testing.T) {
 	ctx := context.Background()
 	store := account.NewStore(testDB)
-	acc, err := store.ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "en", "", "Player")
+	acc, _, err := store.ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "en", "", "Player")
 	if err != nil {
 		t.Fatalf("provision telegram: %v", err)
 	}

backend/internal/inttest/admin_test.go

@@ -222,7 +222,7 @@ func TestConsoleGameDetailRobotSchedule(t *testing.T) {
 func TestConsoleThrottledViewAndFlagClear(t *testing.T) {
 	ctx := context.Background()
 	accounts := account.NewStore(testDB)
-	acc, err := accounts.ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "en", "", "Throttled Player")
+	acc, _, err := accounts.ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "en", "", "Throttled Player")
 	if err != nil {
 		t.Fatalf("provision: %v", err)
 	}

backend/internal/inttest/chat_access_test.go

@@ -0,0 +1,315 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"go.uber.org/zap/zaptest"
+
+	"scrabble/backend/internal/account"
+	"scrabble/backend/internal/notify"
+	"scrabble/backend/internal/server"
+	"scrabble/backend/internal/session"
+)
+
+// chatAccessBody mirrors the backend's /internal/chat-access JSON for the test.
+type chatAccessBody struct {
+	ExternalID string `json:"external_id"`
+	Registered bool   `json:"registered"`
+	Eligible   bool   `json:"eligible"`
+}
+
+// chatAccess issues the gateway-internal chat-access query and asserts a 200.
+func chatAccess(t *testing.T, srv *server.Server, body string) chatAccessBody {
+	t.Helper()
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodPost, "/api/v1/internal/chat-access", strings.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	srv.Handler().ServeHTTP(rec, req)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("chat-access %s = %d: %s", body, rec.Code, rec.Body.String())
+	}
+	var b chatAccessBody
+	if err := json.Unmarshal(rec.Body.Bytes(), &b); err != nil {
+		t.Fatalf("decode chat-access: %v", err)
+	}
+	return b
+}
+
+// TestChatAccessResolver drives the gateway-internal eligibility resolver over HTTP:
+// the registered/suspended/chat_muted truth table by Telegram identity and by account
+// id, the suspension dominating the chat_muted role, an unknown identity reported
+// unregistered, and an account with no Telegram identity carrying an empty external_id.
+func TestChatAccessResolver(t *testing.T) {
+	ctx := context.Background()
+	accounts := account.NewStore(testDB)
+	srv := server.New(":0", server.Deps{Logger: zaptest.NewLogger(t), DB: testDB, Accounts: accounts})
+
+	ext := "tg-" + uuid.NewString()
+	acc, _, err := accounts.ProvisionTelegram(ctx, ext, "en", "", "Chatter")
+	if err != nil {
+		t.Fatalf("provision: %v", err)
+	}
+	id := acc.ID
+
+	byExt := func() chatAccessBody { return chatAccess(t, srv, `{"external_id":"`+ext+`"}`) }
+	byUser := func() chatAccessBody { return chatAccess(t, srv, `{"user_id":"`+id.String()+`"}`) }
+
+	// A registered, unsuspended, unmuted account is eligible by either address, and the
+	// account-id query resolves back to its Telegram identity.
+	if b := byExt(); !b.Registered || !b.Eligible || b.ExternalID != ext {
+		t.Fatalf("fresh by external_id = %+v, want registered+eligible+ext", b)
+	}
+	if b := byUser(); !b.Registered || !b.Eligible || b.ExternalID != ext {
+		t.Fatalf("fresh by user_id = %+v, want registered+eligible+ext", b)
+	}
+
+	// A suspension mutes; a lift restores.
+	if _, err := accounts.Suspend(ctx, id, nil, "", "", nil); err != nil {
+		t.Fatalf("suspend: %v", err)
+	}
+	if b := byExt(); !b.Registered || b.Eligible {
+		t.Fatalf("suspended = %+v, want registered but not eligible", b)
+	}
+	if err := accounts.LiftSuspension(ctx, id); err != nil {
+		t.Fatalf("lift: %v", err)
+	}
+	if b := byExt(); !b.Eligible {
+		t.Fatalf("after lift = %+v, want eligible", b)
+	}
+
+	// The chat_muted role mutes independently; a revoke restores.
+	if err := accounts.GrantRole(ctx, id, account.RoleChatMuted); err != nil {
+		t.Fatalf("grant chat_muted: %v", err)
+	}
+	if b := byExt(); !b.Registered || b.Eligible {
+		t.Fatalf("chat_muted = %+v, want registered but not eligible", b)
+	}
+
+	// Suspension dominates: while chat_muted is set, lifting a concurrent suspension
+	// must not re-grant chat (the role still mutes).
+	if _, err := accounts.Suspend(ctx, id, nil, "", "", nil); err != nil {
+		t.Fatalf("suspend over mute: %v", err)
+	}
+	if b := byExt(); b.Eligible {
+		t.Fatalf("suspended+muted = %+v, want not eligible", b)
+	}
+	if err := accounts.LiftSuspension(ctx, id); err != nil {
+		t.Fatalf("lift over mute: %v", err)
+	}
+	if b := byExt(); b.Eligible {
+		t.Fatalf("lifted but still muted = %+v, want not eligible", b)
+	}
+	if err := accounts.RevokeRole(ctx, id, account.RoleChatMuted); err != nil {
+		t.Fatalf("revoke chat_muted: %v", err)
+	}
+	if b := byExt(); !b.Eligible {
+		t.Fatalf("after revoke = %+v, want eligible", b)
+	}
+
+	// An unknown Telegram identity is unregistered (and thus left muted).
+	if b := chatAccess(t, srv, `{"external_id":"tg-missing-`+uuid.NewString()+`"}`); b.Registered || b.Eligible {
+		t.Fatalf("unknown identity = %+v, want neither registered nor eligible", b)
+	}
+
+	// An account with no Telegram identity (a guest) carries an empty external_id, so
+	// the gateway has nothing to gate.
+	guest := provisionGuest(t)
+	if b := chatAccess(t, srv, `{"user_id":"`+guest.String()+`"}`); b.ExternalID != "" || b.Registered {
+		t.Fatalf("guest by user_id = %+v, want empty external_id and not registered", b)
+	}
+
+	// A request naming neither address is a bad request.
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodPost, "/api/v1/internal/chat-access", strings.NewReader(`{}`))
+	req.Header.Set("Content-Type", "application/json")
+	srv.Handler().ServeHTTP(rec, req)
+	if rec.Code != http.StatusBadRequest {
+		t.Fatalf("empty query = %d, want 400", rec.Code)
+	}
+}
+
+// captureNotifier records every published intent so a test can assert which live
+// events a console action emitted.
+type captureNotifier struct {
+	mu      sync.Mutex
+	intents []notify.Intent
+}
+
+func (c *captureNotifier) Publish(in ...notify.Intent) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.intents = append(c.intents, in...)
+}
+
+// count returns how many intents of kind addressed to user were captured.
+func (c *captureNotifier) count(user uuid.UUID, kind string) int {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	n := 0
+	for _, in := range c.intents {
+		if in.UserID == user && in.Kind == kind {
+			n++
+		}
+	}
+	return n
+}
+
+// TestChatAccessPublishedOnModeration drives the admin console and asserts each
+// moderation action that can change chat eligibility — block, unblock, and the
+// chat_muted role grant/revoke — emits the chat_access_changed signal the gateway
+// turns into a chat-gate command.
+func TestChatAccessPublishedOnModeration(t *testing.T) {
+	notifier := &captureNotifier{}
+	srv := server.New(":0", server.Deps{
+		Logger:   zaptest.NewLogger(t),
+		DB:       testDB,
+		Accounts: account.NewStore(testDB),
+		Games:    newGameService(),
+		Registry: testRegistry,
+		DictDir:  dictDir(),
+		Notifier: notifier,
+	})
+	h := srv.Handler()
+	id := provisionAccount(t)
+	base := "http://admin.test/_gm/users/" + id.String()
+	const origin = "http://admin.test"
+
+	steps := []struct {
+		name, path, body string
+		want             string
+	}{
+		{"block", "/block", "duration=permanent", "Blocked"},
+		{"unblock", "/unblock", "", "Unblocked"},
+		{"grant chat_muted", "/grant-role", "role=chat_muted", "Role granted"},
+		{"revoke chat_muted", "/revoke-role", "role=chat_muted", "Role revoked"},
+	}
+	for i, s := range steps {
+		code, body := consoleDo(h, http.MethodPost, base+s.path, s.body, origin)
+		if code != http.StatusOK || !strings.Contains(body, s.want) {
+			t.Fatalf("%s = %d, has %q = %v", s.name, code, s.want, strings.Contains(body, s.want))
+		}
+		if got := notifier.count(id, notify.KindChatAccessChanged); got != i+1 {
+			t.Fatalf("after %s: chat_access_changed count = %d, want %d", s.name, got, i+1)
+		}
+	}
+}
+
+// TestChatAccessPublishedOnFirstRegistration checks that a Telegram first contact
+// (the sessions/telegram endpoint creating the account) emits chat_access_changed —
+// the re-grant for a user who joined the moderated chat before registering — and that
+// a repeat login does not re-emit.
+func TestChatAccessPublishedOnFirstRegistration(t *testing.T) {
+	notifier := &captureNotifier{}
+	srv := server.New(":0", server.Deps{
+		Logger:   zaptest.NewLogger(t),
+		DB:       testDB,
+		Accounts: account.NewStore(testDB),
+		Sessions: session.NewService(session.NewStore(testDB), session.NewCache()),
+		Notifier: notifier,
+	})
+	h := srv.Handler()
+	ext := "tg-" + uuid.NewString()
+
+	post := func() {
+		rec := httptest.NewRecorder()
+		req := httptest.NewRequest(http.MethodPost, "/api/v1/internal/sessions/telegram",
+			strings.NewReader(`{"external_id":"`+ext+`","language_code":"en","first_name":"Reg"}`))
+		req.Header.Set("Content-Type", "application/json")
+		h.ServeHTTP(rec, req)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("telegram auth = %d: %s", rec.Code, rec.Body.String())
+		}
+	}
+
+	post()
+	acc, err := account.NewStore(testDB).AccountByIdentity(context.Background(), account.KindTelegram, ext)
+	if err != nil {
+		t.Fatalf("lookup: %v", err)
+	}
+	if got := notifier.count(acc.ID, notify.KindChatAccessChanged); got != 1 {
+		t.Fatalf("first registration: chat_access_changed count = %d, want 1", got)
+	}
+	// A repeat login (the account already exists) must not re-emit.
+	post()
+	if got := notifier.count(acc.ID, notify.KindChatAccessChanged); got != 1 {
+		t.Fatalf("repeat login: chat_access_changed count = %d, want still 1", got)
+	}
+}
+
+// TestSuspensionsExpiredBetween checks the sweeper's window query: a non-lifted
+// temporary block whose expiry falls in the window is returned, while one outside the
+// window, a permanent block, and a lifted block are not.
+func TestSuspensionsExpiredBetween(t *testing.T) {
+	ctx := context.Background()
+	accounts := account.NewStore(testDB)
+
+	// A temporary block whose expiry already lapsed at a known instant.
+	tempID := provisionAccount(t)
+	expiry := time.Now().Add(-time.Hour).Truncate(time.Second)
+	if _, err := accounts.Suspend(ctx, tempID, &expiry, "", "", nil); err != nil {
+		t.Fatalf("suspend temp: %v", err)
+	}
+
+	contains := func(ids []uuid.UUID, want uuid.UUID) bool {
+		for _, id := range ids {
+			if id == want {
+				return true
+			}
+		}
+		return false
+	}
+
+	// A window straddling the expiry returns the account.
+	got, err := accounts.SuspensionsExpiredBetween(ctx, expiry.Add(-time.Minute), expiry.Add(time.Minute))
+	if err != nil {
+		t.Fatalf("expired between: %v", err)
+	}
+	if !contains(got, tempID) {
+		t.Fatalf("window over expiry missing the lapsed block %s", tempID)
+	}
+	// A window entirely after the expiry does not.
+	got, err = accounts.SuspensionsExpiredBetween(ctx, expiry.Add(time.Minute), expiry.Add(2*time.Minute))
+	if err != nil {
+		t.Fatalf("expired between (after): %v", err)
+	}
+	if contains(got, tempID) {
+		t.Fatalf("window after expiry should not return %s", tempID)
+	}
+
+	// A permanent block never appears, even in a wide window.
+	permID := provisionAccount(t)
+	if _, err := accounts.Suspend(ctx, permID, nil, "", "", nil); err != nil {
+		t.Fatalf("suspend perm: %v", err)
+	}
+	// A lifted block does not appear either. The block must still be in force when lifted
+	// (LiftSuspension only lifts in-force blocks), so its expiry is in the future and the
+	// wide window below still covers it — yet lifted_at excludes it.
+	liftID := provisionAccount(t)
+	liftExpiry := time.Now().Add(30 * time.Minute).Truncate(time.Second)
+	if _, err := accounts.Suspend(ctx, liftID, &liftExpiry, "", "", nil); err != nil {
+		t.Fatalf("suspend lift: %v", err)
+	}
+	if err := accounts.LiftSuspension(ctx, liftID); err != nil {
+		t.Fatalf("lift: %v", err)
+	}
+	wide, err := accounts.SuspensionsExpiredBetween(ctx, time.Now().Add(-2*time.Hour), time.Now().Add(time.Hour))
+	if err != nil {
+		t.Fatalf("expired between (wide): %v", err)
+	}
+	if contains(wide, permID) {
+		t.Fatalf("permanent block %s must not be reported as expired", permID)
+	}
+	if contains(wide, liftID) {
+		t.Fatalf("lifted block %s must not be reported as expired", liftID)
+	}
+}

backend/internal/inttest/game_test.go

@@ -543,6 +543,12 @@ func TestEvaluatePlayPreview(t *testing.T) {
 	if bad.Valid {
 		t.Error("disconnected play must be invalid")
 	}
+
+	// A non-seated account cannot preview: with the game warm in the live cache, the
+	// membership check runs against the cached seat list (the hot path that skips GetGame).
+	if _, err := svc.EvaluatePlay(ctx, g.ID, provisionAccount(t), hint.Tiles); !errors.Is(err, game.ErrNotAPlayer) {
+		t.Errorf("evaluate by a non-player = %v, want ErrNotAPlayer", err)
+	}
 }
 
 // TestConcurrentSubmitSerialized confirms the per-game lock lets only one of two

backend/internal/inttest/suspension_gate_test.go

@@ -38,7 +38,7 @@ func TestSuspensionGate(t *testing.T) {
 		Accounts: accounts,
 	})
 
-	acc, err := accounts.ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "ru", "", "Blocked")
+	acc, _, err := accounts.ProvisionTelegram(ctx, "tg-"+uuid.NewString(), "ru", "", "Blocked")
 	if err != nil {
 		t.Fatalf("provision: %v", err)
 	}

backend/internal/inttest/userlist_test.go

@@ -18,7 +18,7 @@ func TestUserListFilter(t *testing.T) {
 	st := account.NewStore(testDB)
 	uniq := uuid.NewString()
 
-	human, err := st.ProvisionTelegram(ctx, "tg-"+uniq, "en", "", "Zzqxhuman")
+	human, _, err := st.ProvisionTelegram(ctx, "tg-"+uniq, "en", "", "Zzqxhuman")
 	if err != nil {
 		t.Fatalf("provision human: %v", err)
 	}

backend/internal/notify/events.go

@@ -216,6 +216,16 @@ func BannerChanged(userID uuid.UUID) Intent {
 	return Notification(userID, NotifyBanner)
 }
 
+// ChatAccessChanged signals that userID's eligibility to write in the moderated
+// Telegram discussion chat may have changed (an admin block/unblock, a chat_muted
+// grant/revoke, or a temporary block lapsing). It carries no payload: the gateway
+// resolves the user's Telegram identity and current eligibility and pushes the
+// resulting chat-gate command to the bot. Unlike the lobby notifications it is an
+// infra signal — a distinct top-level kind, never an out-of-app rendered message.
+func ChatAccessChanged(userID uuid.UUID) Intent {
+	return Intent{UserID: userID, Kind: KindChatAccessChanged, EventID: eventID()}
+}
+
 // eventID returns a best-effort correlation id for one emitted event.
 func eventID() string {
 	if id, err := uuid.NewV7(); err == nil {

backend/internal/notify/notify.go

@@ -35,6 +35,13 @@ const (
 	// KindGameOver announces a finished game to each seated player, driving the
 	// out-of-app "game over" push.
 	KindGameOver = "game_over"
+	// KindChatAccessChanged signals that a player's eligibility to write in the
+	// moderated Telegram discussion chat may have changed (an admin block or unblock,
+	// a chat_muted grant or revoke, or a temporary block lapsing). It carries no
+	// payload and is never fanned out to in-app clients: the gateway consumes it to
+	// resolve the player's Telegram identity and current eligibility and push the
+	// resulting chat-gate command to the bot.
+	KindChatAccessChanged = "chat_access_changed"
 )
 
 // Notification sub-kinds carried in a KindNotification event payload; the client

backend/internal/server/chataccess.go

@@ -0,0 +1,131 @@
+package server
+
+import (
+	"context"
+	"errors"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/account"
+	"scrabble/backend/internal/notify"
+)
+
+// chatAccessRequest is the gateway's chat write-eligibility query, addressed either
+// by Telegram identity (ExternalID — the join path, when the bot sees a user enter
+// the chat) or by account id (UserID — the change path, resolving an emitted
+// chat-access-changed event). Exactly one field is set.
+type chatAccessRequest struct {
+	ExternalID string `json:"external_id"`
+	UserID     string `json:"user_id"`
+}
+
+// chatAccessResponse is the resolved eligibility. ExternalID echoes the account's
+// Telegram identity (empty when it has none — the gateway then has nothing to gate);
+// Registered reports whether the lookup found an account at all; Eligible is the
+// final gate the bot applies (registered and neither admin-suspended nor chat-muted).
+type chatAccessResponse struct {
+	ExternalID string `json:"external_id"`
+	Registered bool   `json:"registered"`
+	Eligible   bool   `json:"eligible"`
+}
+
+// handleChatAccess resolves whether a Telegram user may write in the moderated
+// discussion chat. It is gateway-internal: the gateway's bot-link serves the bot's
+// join-time query (by external_id) and resolves an emitted chat-access-changed event
+// (by user_id) through it.
+func (s *Server) handleChatAccess(c *gin.Context) {
+	var req chatAccessRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		abortBadRequest(c, "invalid body")
+		return
+	}
+	switch {
+	case req.ExternalID != "":
+		s.respondChatAccessByExternalID(c, req.ExternalID)
+	case req.UserID != "":
+		s.respondChatAccessByUserID(c, req.UserID)
+	default:
+		abortBadRequest(c, "external_id or user_id required")
+	}
+}
+
+// respondChatAccessByExternalID answers the join-path query: an unknown identity is
+// reported unregistered (and left muted); a known one carries its current eligibility.
+func (s *Server) respondChatAccessByExternalID(c *gin.Context, externalID string) {
+	ctx := c.Request.Context()
+	resp := chatAccessResponse{ExternalID: externalID}
+	acc, err := s.accounts.AccountByIdentity(ctx, account.KindTelegram, externalID)
+	if errors.Is(err, account.ErrNotFound) {
+		c.JSON(http.StatusOK, resp)
+		return
+	}
+	if err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	resp.Registered = true
+	eligible, err := s.chatEligible(ctx, acc.ID)
+	if err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	resp.Eligible = eligible
+	c.JSON(http.StatusOK, resp)
+}
+
+// respondChatAccessByUserID answers the change-path query: an account with no
+// Telegram identity carries an empty external_id (nothing for the gateway to gate);
+// otherwise it carries the identity and the current eligibility.
+func (s *Server) respondChatAccessByUserID(c *gin.Context, raw string) {
+	ctx := c.Request.Context()
+	uid, err := uuid.Parse(raw)
+	if err != nil {
+		abortBadRequest(c, "invalid user_id")
+		return
+	}
+	var resp chatAccessResponse
+	ext, err := s.accounts.IdentityExternalID(ctx, uid, account.KindTelegram)
+	if errors.Is(err, account.ErrNotFound) {
+		c.JSON(http.StatusOK, resp)
+		return
+	}
+	if err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	resp.ExternalID = ext
+	resp.Registered = true
+	eligible, err := s.chatEligible(ctx, uid)
+	if err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	resp.Eligible = eligible
+	c.JSON(http.StatusOK, resp)
+}
+
+// chatEligible reports whether the account may write in the moderated discussion
+// chat: not currently admin-suspended and not holding the chat_muted role. A
+// suspension dominates — it mutes regardless of the role. Registration is established
+// by the caller's identity lookup.
+func (s *Server) chatEligible(ctx context.Context, accountID uuid.UUID) (bool, error) {
+	if _, blocked, err := s.accounts.CurrentSuspension(ctx, accountID); err != nil {
+		return false, err
+	} else if blocked {
+		return false, nil
+	}
+	muted, err := s.accounts.HasRole(ctx, accountID, account.RoleChatMuted)
+	if err != nil {
+		return false, err
+	}
+	return !muted, nil
+}
+
+// publishChatAccessChange emits the chat-access-changed signal for the account, so
+// the gateway re-resolves the player's chat eligibility and pushes the chat-gate
+// command to the bot. Best-effort (notify.Nop when no notifier is wired).
+func (s *Server) publishChatAccessChange(id uuid.UUID) {
+	s.notifier.Publish(notify.ChatAccessChanged(id))
+}

backend/internal/server/handlers.go

@@ -37,6 +37,13 @@ func (s *Server) registerRoutes() {
 		// before delivering an out-of-app notification.
 		in.POST("/push-target", s.handlePushTarget)
 	}
+	if s.accounts != nil {
+		// Moderated-chat write eligibility for the Telegram bot: resolve a Telegram
+		// identity (the bot's join-time query) or an account id (a chat-access-changed
+		// event) to whether the user may write in the discussion chat. It needs only the
+		// account store, not the session service, so it registers independently.
+		s.internal.POST("/chat-access", s.handleChatAccess)
+	}
 	if s.ratewatch != nil {
 		// The gateway's periodic rate-limiter rejection summary: feeds the
 		// admin console's throttled view and the high-rate auto-flag.

backend/internal/server/handlers_admin_console.go

@@ -987,6 +987,9 @@ func (s *Server) consoleBlockUser(c *gin.Context) {
 		s.consoleError(c, err)
 		return
 	}
+	// Re-evaluate the player's moderated-chat write access: a block mutes them in
+	// the discussion chat if they are currently in it.
+	s.publishChatAccessChange(id)
 	s.renderConsoleMessage(c, "Blocked", fmt.Sprintf("account blocked; %d game(s) forfeited", forfeited), back)
 }
 
@@ -1001,6 +1004,9 @@ func (s *Server) consoleUnblockUser(c *gin.Context) {
 		s.consoleError(c, err)
 		return
 	}
+	// Re-evaluate the player's moderated-chat write access: an unblock restores it
+	// (unless they are still chat-muted) for a member currently in the chat.
+	s.publishChatAccessChange(id)
 	s.renderConsoleMessage(c, "Unblocked", "the block was lifted; lost games are not restored", "/_gm/users/"+id.String())
 }
 

backend/internal/server/handlers_admin_feedback.go

@@ -248,6 +248,9 @@ func (s *Server) consoleGrantRole(c *gin.Context) {
 	if role == account.RoleNoBanner {
 		s.publishBannerChange(id)
 	}
+	if role == account.RoleChatMuted {
+		s.publishChatAccessChange(id)
+	}
 	s.renderConsoleMessage(c, "Role granted", "granted "+role, back)
 }
 
@@ -270,6 +273,9 @@ func (s *Server) consoleRevokeRole(c *gin.Context) {
 	if role == account.RoleNoBanner {
 		s.publishBannerChange(id)
 	}
+	if role == account.RoleChatMuted {
+		s.publishChatAccessChange(id)
+	}
 	s.renderConsoleMessage(c, "Role revoked", "revoked "+role, back)
 }
 

backend/internal/server/handlers_auth.go

@@ -35,11 +35,17 @@ func (s *Server) handleTelegramAuth(c *gin.Context) {
 		abortBadRequest(c, "external_id is required")
 		return
 	}
-	acc, err := s.accounts.ProvisionTelegram(c.Request.Context(), req.ExternalID, req.LanguageCode, req.Username, req.FirstName)
+	acc, created, err := s.accounts.ProvisionTelegram(c.Request.Context(), req.ExternalID, req.LanguageCode, req.Username, req.FirstName)
 	if err != nil {
 		s.abortErr(c, err)
 		return
 	}
+	if created {
+		// First registration: re-evaluate moderated-chat write access, so a user who
+		// joined the chat before registering is granted on the spot (no chat_member
+		// event fires on registration).
+		s.publishChatAccessChange(acc.ID)
+	}
 	s.mintSession(c, acc)
 }
 

deploy/.env.example

@@ -46,6 +46,10 @@ GRAFANA_ADMIN_PASSWORD=admin
 AWG_CONF=                              # required; AmneziaWG sidecar config (the bot's Telegram egress)
 TELEGRAM_BOT_TOKEN=                    # required
 TELEGRAM_GAME_CHANNEL_ID=
+TELEGRAM_CHAT_ID=                      # moderated discussion chat (channel's linked group); empty disables gating
+TELEGRAM_PROMO_BOT_TOKEN=             # optional standalone promo bot token; empty disables it
+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_MINIAPP_URL=                  # required
 TELEGRAM_TEST_ENV=false
 TELEGRAM_API_BASE_URL=

deploy/README.md

@@ -17,11 +17,12 @@ operational reference for **every environment variable**.
 | `backend` | built (`backend/Dockerfile`) | Domain service; bakes in the DAWG dictionaries; runs migrations at boot. |
 | `postgres` | `postgres:17-alpine` | Database (named volume, `pg_isready` healthcheck). |
 | `validator` | built (`platform/telegram/Dockerfile`, target `validator`) | Telegram HMAC validator (no VPN, no Bot API); internal gRPC at `validator:9091`. Game login depends only on this. |
-| `vpn` + `bot` | sidecar + built (`platform/telegram/Dockerfile`, target `bot`) | Telegram bot; egresses through the AmneziaWG sidecar; holds no inbound port — dials the gateway bot-link (mTLS) at `gateway:9443`. |
+| `vpn` + `bot` | sidecar + built (`platform/telegram/Dockerfile`, target `bot`) | Telegram bot, gated to the **`telegram-local`** profile; egresses through the AmneziaWG sidecar and dials the gateway bot-link (mTLS) at `gateway:9443`. The test contour activates the profile; the prod **main** host omits it and runs the bot standalone on its **own host** (`docker-compose.bot.yml`, no VPN — native Bot API egress). |
 | `otelcol` | `otel/opentelemetry-collector-contrib` | OTLP/gRPC `:4317` → Prometheus scrape (`:9464`) + Tempo. |
-| `prometheus` | `prom/prometheus` | Metrics, 15d retention. |
+| `prometheus` | `prom/prometheus` | Metrics, 15d retention (7d in prod). |
 | `tempo` | `grafana/tempo` | Traces, 72h retention. |
 | `grafana` | `grafana/grafana` | Dashboards (provisioned), anonymous-admin behind caddy's `/_gm/grafana`. |
+| `node_exporter` | `quay.io/prometheus/node-exporter` | Host CPU/memory/disk metrics (Prometheus job `node`); the OOM signal on the tight prod main host (2 vCPU / 1.9 GiB). |
 
 Networking: inter-service traffic is on the private `internal` network
 (project-scoped DNS); only `caddy` joins the shared external `edge` network so the
@@ -59,7 +60,6 @@ compose binds from this directory.
 | Variable | Gitea kind | Purpose |
 | --- | --- | --- |
 | `POSTGRES_PASSWORD` | secret | Postgres password (also embedded in `BACKEND_POSTGRES_DSN`). |
-| `AWG_CONF` | secret | AmneziaWG config for the VPN sidecar (the bot's only Telegram egress in the test contour). **Must not contain a `DNS=` line** — it hijacks the shared netns's resolv.conf and breaks the bot resolving `otelcol` / `gateway`. Without it, Docker's resolver handles `otelcol`, `gateway` and `api.telegram.org`. |
 | `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. |
 
@@ -67,6 +67,13 @@ compose binds from this directory.
 secret) and the bot (Bot API). It defaults to empty in compose, but both **fail at
 boot** when it is empty.
 
+**Conditionally — `AWG_CONF`** (secret): the AmneziaWG config for the VPN sidecar, needed
+only when the `telegram-local` profile runs (the test contour and local runs with the
+bot). It is **not** `:?`-guarded — compose interpolates profiled-out services too, so the
+prod main host (no VPN) must not require it. It **must not contain a `DNS=` line** — that
+hijacks the shared netns's resolv.conf and breaks the bot resolving `otelcol` / `gateway`;
+without it Docker's resolver handles `otelcol`, `gateway` and `api.telegram.org`.
+
 ## Optional variables (with defaults)
 
 | Variable | Gitea kind | Default | Purpose |
@@ -110,6 +117,65 @@ collector's / gateway's internal IP is fine (connected route), but its `AWG_CONF
 which resolves `otelcol`, `gateway` and `api.telegram.org`. `GATEWAY_ADMIN_*` is
 intentionally **unset** — caddy owns `/_gm` in the contour.
 
+## Production rollout
+
+Prod runs on **two hosts** (main = full stack + ACME on the domain; tg = the bot only,
+native Bot API, no VPN), one-time provisioned by **[`ansible/`](ansible/)** (docker, a
+non-sudo `deploy` user holding the CI key, key-only sshd, default-deny ufw, fail2ban).
+Re-run `ansible/` after a host resize — it is idempotent.
+
+**To roll out:** merge `development → master` (CI green), then run the **`prod-deploy`**
+workflow manually (Gitea → Actions → prod-deploy → run from `master`, input
+`confirm=deploy`). It builds + pushes the images to the registry, ships the
+compose/config/certs/env over SSH, deploys the main host with `prod-deploy.sh` (rolling,
+health-gated, **auto-rollback to the previous tag**), then the bot host, then probes the
+public site. After `master` is green this workflow is the **only** thing that touches
+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).
+
+**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
+before running the deploy:
+
+```sh
+git tag -a v1.0.0 -m v1.0.0 && git push origin v1.0.0
+```
+
+**Manual rollback** (any time after a successful deploy). Run the **`prod-rollback`**
+workflow (Gitea → Actions → prod-rollback, `confirm=rollback`). Leave `target_version`
+blank to roll back to the previously deployed version (read from the host's
+`PREVIOUS_TAG`), or set it to a release tag from the **Releases** page. It re-deploys
+that already-published image rolling + health-gated — no rebuild, no DB migration
+(image rollback is DB-safe under the expand-contract rule). The registry keeps every
+release tag, so any prior release is reachable.
+
+**Migrations** must be **expand-contract** (backward-compatible; goose is forward-only):
+the automatic rollback is image-only and never restores the DB. A deploy that changes
+`backend/internal/postgres/migrations/` opens a maintenance window — the backend (sole
+writer) is stopped for a consistent `pg_dump` into `/opt/scrabble/dumps` before the new
+backend migrates. **Manual DB restore** (only if a migration was destructive):
+`docker exec -i scrabble-postgres psql -U scrabble -d scrabble -c 'DROP SCHEMA backend CASCADE'`,
+then pipe the dump into the same `psql`, and redeploy the matching old tag.
+
+**bot-link cert rotation:** regenerate (`deploy/gen-certs.sh /tmp/c --force`), reset the
+five `PROD_BOTLINK_*` secrets from `/tmp/c`, and re-run the workflow — both hosts redeploy
+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.
+
+**`PROD_` Gitea set** (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, 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,
+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}`.
+
 ## Host-side setup (outside this repo)
 
 - **`edge` network** must exist on the host (`docker network create edge`).

deploy/ansible/README.md

@@ -0,0 +1,49 @@
+# Prod host provisioning (Stage 18)
+
+Idempotent Ansible that prepares the two production hosts. It installs Docker, a
+non-sudo `deploy` service account, SSH hardening, a default-deny firewall,
+fail2ban, unattended security upgrades and time sync. It does **not** deploy the
+application — that is `.gitea/workflows/prod-deploy.yaml`'s job, running as the
+`deploy` account this playbook creates.
+
+Hosts are referenced by `~/.ssh/config` aliases (`scrabble-main-ops`,
+`scrabble-tg-ops`), so no IPs or key paths live in the repo.
+
+## Prerequisites (controller)
+
+- `ansible` with the bundled collections (`community.general`, `community.docker`,
+  `ansible.posix`).
+- The two hosts reachable as root via the ssh-config aliases, host keys already
+  accepted into `known_hosts` (`host_key_checking = True`).
+
+## One-time: the CI deploy key
+
+The CI prod-deploy workflow logs into the hosts as `deploy` using a dedicated
+key. Generate it once on the controller, authorize its public half via the
+playbook, and store its private half **only** in the Gitea `PROD_SSH_KEY` secret:
+
+```sh
+ssh-keygen -t ed25519 -N '' -C scrabble-ci-deploy \
+  -f ~/.ssh/scrabble_ci_deploy_ed25519
+# private half -> Gitea secret PROD_SSH_KEY (set via API); never commit it
+```
+
+## Run
+
+```sh
+cd deploy/ansible
+ansible-playbook site.yml
+```
+
+The playbook reads the public key from `~/.ssh/scrabble_ci_deploy_ed25519.pub` by
+default; override with `-e deploy_ci_pubkey_path=/path/to/key.pub`. Re-running is
+safe (idempotent) and survives a host resize.
+
+## What each host gets
+
+- **both** (`common`): docker-ce + compose plugin, `daemon.json` (live-restore,
+  10m×3 log rotation), `deploy` user (docker group, no sudo), key-only sshd,
+  `ufw` default-deny incoming + allow SSH, fail2ban sshd jail, unattended
+  upgrades, chrony, `/opt/scrabble/{config,certs,dumps,images}`.
+- **main**: `ufw` opens 80/443/9443; the external `edge` docker network.
+- **tg**: verifies direct `api.telegram.org` egress (the no-VPN assumption).

deploy/ansible/ansible.cfg

@@ -0,0 +1,11 @@
+[defaults]
+inventory = inventory.ini
+roles_path = roles
+interpreter_python = /usr/bin/python3
+host_key_checking = True
+stdout_callback = yaml
+deprecation_warnings = False
+retry_files_enabled = False
+
+[ssh_connection]
+pipelining = True

deploy/ansible/group_vars/all.yml

@@ -0,0 +1,21 @@
+---
+# Service account the CI prod-deploy workflow uses to drive docker on the hosts.
+# Membership in the docker group is root-equivalent (docker socket access), which
+# is all the deploy workflow needs; the account is deliberately not given sudo.
+deploy_user: deploy
+
+# Public half of the dedicated CI deploy SSH key, read from the controller at run
+# time. The private half is generated on the controller during provisioning and
+# stored ONLY in the Gitea PROD_SSH_KEY secret; it is never committed. Override the
+# path with -e deploy_ci_pubkey_path=/path/to/key.pub if the key lives elsewhere.
+deploy_ci_pubkey_path: "{{ lookup('env', 'HOME') }}/.ssh/scrabble_ci_deploy_ed25519.pub"
+deploy_ci_pubkey: "{{ lookup('file', deploy_ci_pubkey_path) }}"
+
+# Base directory the deploy workflow rsyncs compose files, config, certs and dumps
+# into. Owned by deploy_user so the workflow needs no elevation.
+scrabble_base_dir: /opt/scrabble
+
+# Docker daemon json-file log rotation, mirroring the compose x-logging anchor so
+# the host's own containers (and any ad-hoc runs) rotate identically.
+docker_log_max_size: "10m"
+docker_log_max_file: "3"

deploy/ansible/inventory.ini

@@ -0,0 +1,19 @@
+# Production inventory for Stage 18.
+#
+# Hosts resolve through the operator's ~/.ssh/config aliases, so HostName (public
+# IP), User and IdentityFile live there — no IPs or key paths are committed here.
+#   scrabble-main-ops -> main stack host (public IP, domain erudit-game.ru)
+#   scrabble-tg-ops   -> Telegram bot host (direct Bot API egress, no VPN)
+
+[main]
+scrabble-main-ops
+
+[tg]
+scrabble-tg-ops
+
+[prod:children]
+main
+tg
+
+[prod:vars]
+ansible_user=root

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

@@ -0,0 +1,15 @@
+---
+- name: restart docker
+  ansible.builtin.service:
+    name: docker
+    state: restarted
+
+- name: reload sshd
+  ansible.builtin.service:
+    name: ssh
+    state: reloaded
+
+- name: restart fail2ban
+  ansible.builtin.service:
+    name: fail2ban
+    state: restarted

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

@@ -0,0 +1,167 @@
+---
+# Common baseline applied to both prod hosts: Docker engine, a non-sudo deploy
+# service account, SSH hardening, a default-deny firewall, fail2ban, unattended
+# security upgrades and time sync. Every task is idempotent.
+
+- name: Install base packages
+  ansible.builtin.apt:
+    name:
+      - ca-certificates
+      - curl
+      - gnupg
+      - ufw
+      - fail2ban
+      - unattended-upgrades
+      - chrony
+    state: present
+    update_cache: true
+    cache_valid_time: 3600
+
+# --- Docker engine (official repo; trixie is published upstream) ---------------
+
+- name: Create apt keyring directory
+  ansible.builtin.file:
+    path: /etc/apt/keyrings
+    state: directory
+    mode: "0755"
+
+- name: Install Docker apt GPG key
+  ansible.builtin.get_url:
+    url: https://download.docker.com/linux/debian/gpg
+    dest: /etc/apt/keyrings/docker.asc
+    mode: "0644"
+
+- name: Add Docker apt repository
+  ansible.builtin.apt_repository:
+    repo: >-
+      deb [arch=amd64 signed-by=/etc/apt/keyrings/docker.asc]
+      https://download.docker.com/linux/debian {{ ansible_distribution_release }} stable
+    filename: docker
+    state: present
+
+- name: Install Docker engine and the compose plugin
+  ansible.builtin.apt:
+    name:
+      - docker-ce
+      - docker-ce-cli
+      - containerd.io
+      - docker-buildx-plugin
+      - docker-compose-plugin
+    state: present
+    update_cache: true
+
+- name: Configure the Docker daemon (live-restore + log rotation)
+  ansible.builtin.template:
+    src: daemon.json.j2
+    dest: /etc/docker/daemon.json
+    mode: "0644"
+  notify: restart docker
+
+- name: Enable and start Docker
+  ansible.builtin.service:
+    name: docker
+    enabled: true
+    state: started
+
+# --- Deploy service account ----------------------------------------------------
+
+- name: Create the deploy service account
+  ansible.builtin.user:
+    name: "{{ deploy_user }}"
+    groups: docker
+    append: true
+    shell: /bin/bash
+    create_home: true
+
+- name: Ensure the deploy .ssh directory
+  ansible.builtin.file:
+    path: "/home/{{ deploy_user }}/.ssh"
+    state: directory
+    owner: "{{ deploy_user }}"
+    group: "{{ deploy_user }}"
+    mode: "0700"
+
+- name: Authorize the CI deploy SSH key (exclusive)
+  ansible.builtin.copy:
+    dest: "/home/{{ deploy_user }}/.ssh/authorized_keys"
+    content: "{{ deploy_ci_pubkey }}\n"
+    owner: "{{ deploy_user }}"
+    group: "{{ deploy_user }}"
+    mode: "0600"
+
+# --- SSH hardening -------------------------------------------------------------
+
+- name: Harden sshd (key-only auth)
+  ansible.builtin.template:
+    src: sshd-hardening.conf.j2
+    dest: /etc/ssh/sshd_config.d/10-scrabble-hardening.conf
+    mode: "0644"
+    validate: sshd -t -f %s
+  notify: reload sshd
+
+# --- Firewall (default deny incoming) ------------------------------------------
+# SSH is allowed before the policy flips so enabling ufw never locks us out.
+
+- name: Allow SSH through the firewall
+  community.general.ufw:
+    rule: allow
+    name: OpenSSH
+
+- name: Default-deny incoming, allow outgoing
+  community.general.ufw:
+    direction: "{{ item.direction }}"
+    policy: "{{ item.policy }}"
+  loop:
+    - { direction: incoming, policy: deny }
+    - { direction: outgoing, policy: allow }
+
+- name: Enable the firewall
+  community.general.ufw:
+    state: enabled
+
+# --- fail2ban ------------------------------------------------------------------
+
+- name: Configure the fail2ban sshd jail
+  ansible.builtin.template:
+    src: jail.local.j2
+    dest: /etc/fail2ban/jail.local
+    mode: "0644"
+  notify: restart fail2ban
+
+- name: Enable and start fail2ban
+  ansible.builtin.service:
+    name: fail2ban
+    enabled: true
+    state: started
+
+# --- Unattended security upgrades + time sync ----------------------------------
+
+- name: Enable unattended upgrades
+  ansible.builtin.copy:
+    dest: /etc/apt/apt.conf.d/20auto-upgrades
+    mode: "0644"
+    content: |
+      APT::Periodic::Update-Package-Lists "1";
+      APT::Periodic::Unattended-Upgrade "1";
+
+- name: Enable and start chrony
+  ansible.builtin.service:
+    name: chrony
+    enabled: true
+    state: started
+
+# --- Deploy directories --------------------------------------------------------
+
+- name: Create the scrabble base directories
+  ansible.builtin.file:
+    path: "{{ scrabble_base_dir }}/{{ item }}"
+    state: directory
+    owner: "{{ deploy_user }}"
+    group: "{{ deploy_user }}"
+    mode: "0750"
+  loop:
+    - ""
+    - config
+    - certs
+    - dumps
+    - images

deploy/ansible/roles/common/templates/daemon.json.j2

@@ -0,0 +1,8 @@
+{
+  "live-restore": true,
+  "log-driver": "json-file",
+  "log-opts": {
+    "max-size": "{{ docker_log_max_size }}",
+    "max-file": "{{ docker_log_max_file }}"
+  }
+}

deploy/ansible/roles/common/templates/jail.local.j2

@@ -0,0 +1,9 @@
+# Managed by Ansible (deploy/ansible).
+[DEFAULT]
+bantime = 1h
+findtime = 10m
+maxretry = 5
+backend = systemd
+
+[sshd]
+enabled = true

deploy/ansible/roles/common/templates/sshd-hardening.conf.j2

@@ -0,0 +1,6 @@
+# Managed by Ansible (deploy/ansible). Key-only authentication.
+# root stays reachable by key (prohibit-password) for provisioning re-runs.
+PasswordAuthentication no
+PermitRootLogin prohibit-password
+PubkeyAuthentication yes
+KbdInteractiveAuthentication no

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

@@ -0,0 +1,18 @@
+---
+# Main stack host: public web + bot-link ports and the external 'edge' network
+# the compose stack attaches caddy to.
+
+- name: Open public web and bot-link ports
+  community.general.ufw:
+    rule: allow
+    port: "{{ item }}"
+    proto: tcp
+  loop:
+    - "80"    # HTTP (ACME challenge + redirect to HTTPS)
+    - "443"   # HTTPS (caddy edge)
+    - "9443"  # bot-link mTLS (remote bot dials in; mutual TLS gates access)
+
+- name: Ensure the external 'edge' docker network exists
+  community.docker.docker_network:
+    name: edge
+    state: present

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

@@ -0,0 +1,19 @@
+---
+# Telegram bot host: holds no inbound port beyond SSH (the bot dials out to the
+# Bot API and into the main host's bot-link). We only verify direct Bot API
+# egress here, since the "no VPN" decision depends on it.
+
+- name: Verify direct Telegram Bot API egress (no VPN on this host)
+  ansible.builtin.uri:
+    url: https://api.telegram.org/
+    method: GET
+    status_code: [200, 301, 302, 401, 404]   # any HTTP reply proves reachability
+    timeout: 10
+  register: tg_egress
+  failed_when: false
+
+- name: Report Telegram reachability
+  ansible.builtin.debug:
+    msg: >-
+      api.telegram.org reachable:
+      {{ (tg_egress.status | default(0) | int) > 0 }} (status {{ tg_egress.status | default('none') }})

deploy/ansible/site.yml

@@ -0,0 +1,31 @@
+---
+# Stage 18 host provisioning. Idempotent: safe to re-run after a host resize.
+# Prepares hosts only (docker, hardening, service account, firewall); the
+# application is deployed separately by .gitea/workflows/prod-deploy.yaml.
+
+- name: Common baseline (both hosts)
+  hosts: prod
+  become: true
+  pre_tasks:
+    - name: Require a well-formed CI deploy public key
+      ansible.builtin.assert:
+        that:
+          - deploy_ci_pubkey | length > 0
+          - deploy_ci_pubkey is search('^(ssh|ecdsa)-')
+        fail_msg: >-
+          deploy_ci_pubkey is empty or malformed. Generate the key first
+          (see deploy/ansible/README.md) or override deploy_ci_pubkey_path.
+  roles:
+    - common
+
+- name: Main stack host
+  hosts: main
+  become: true
+  roles:
+    - main
+
+- name: Telegram bot host
+  hosts: tg
+  become: true
+  roles:
+    - tg

deploy/docker-compose.bot.yml

@@ -0,0 +1,53 @@
+# Production Telegram bot host descriptor (standalone — NOT an overlay). Run only on
+# the bot host:
+#   docker compose -f docker-compose.bot.yml up -d
+#
+# The bot egresses to the Bot API directly (no VPN sidecar) and dials the main host's
+# published bot-link :9443 over mTLS. It exports no telemetry — otelcol lives on the
+# main host and is unreachable from here — so observe it via `docker logs` on this host.
+# Values come from the prod-deploy workflow (PROD_ secrets/variables); BOT_IMAGE is the
+# pushed registry tag and BOTLINK_GATEWAY_ADDR is the main host's <ip>:9443.
+name: scrabble-bot
+
+services:
+  bot:
+    container_name: scrabble-telegram-bot
+    image: ${BOT_IMAGE:?set BOT_IMAGE to the registry tag}
+    restart: unless-stopped
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+    environment:
+      TELEGRAM_BOT_TOKEN: ${TELEGRAM_BOT_TOKEN:?set TELEGRAM_BOT_TOKEN}
+      TELEGRAM_GAME_CHANNEL_ID: ${TELEGRAM_GAME_CHANNEL_ID:-}
+      TELEGRAM_CHAT_ID: ${TELEGRAM_CHAT_ID:-}
+      TELEGRAM_PROMO_BOT_TOKEN: ${TELEGRAM_PROMO_BOT_TOKEN:-}
+      TELEGRAM_BOT_USERNAME: ${TELEGRAM_BOT_USERNAME:-}
+      TELEGRAM_BOT_LINK: ${TELEGRAM_BOT_LINK:-}
+      TELEGRAM_MINIAPP_URL: ${TELEGRAM_MINIAPP_URL:?set TELEGRAM_MINIAPP_URL}
+      # Real Bot API in prod (the test contour pins TELEGRAM_TEST_ENV=true instead).
+      TELEGRAM_TEST_ENV: "false"
+      TELEGRAM_API_BASE_URL: ${TELEGRAM_API_BASE_URL:-}
+      TELEGRAM_OWNS_UPDATES: "true"
+      # Dials the main host's published bot-link. ServerName stays `gateway` (the cert
+      # SAN), so TLS validation is independent of the dial address.
+      TELEGRAM_GATEWAY_ADDR: ${BOTLINK_GATEWAY_ADDR:?set BOTLINK_GATEWAY_ADDR (main:9443)}
+      TELEGRAM_BOTLINK_SERVER_NAME: gateway
+      TELEGRAM_BOTLINK_TLS_CERT: /certs/bot.crt
+      TELEGRAM_BOTLINK_TLS_KEY: /certs/bot.key
+      TELEGRAM_BOTLINK_TLS_CA: /certs/ca.crt
+      TELEGRAM_LOG_LEVEL: ${LOG_LEVEL:-info}
+      TELEGRAM_SERVICE_NAME: scrabble-telegram-bot
+      # No telemetry export: otelcol is on the main host, unreachable from here.
+      TELEGRAM_OTEL_TRACES_EXPORTER: none
+      TELEGRAM_OTEL_METRICS_EXPORTER: none
+      GOMAXPROCS: "1"
+    volumes:
+      - ${SCRABBLE_CONFIG_DIR:-.}/certs:/certs:ro
+    deploy:
+      resources:
+        limits:
+          cpus: "1.0"
+          memory: 256M

deploy/docker-compose.prod.yml

@@ -0,0 +1,98 @@
+# Production main-host overlay, applied on top of docker-compose.yml on the main host:
+#   docker compose -f docker-compose.yml -f docker-compose.prod.yml up -d
+#
+# It (1) publishes caddy 80/443 — there is no host caddy in prod, so the contour caddy
+# owns the edge and does its own ACME on CADDY_SITE_ADDRESS — and the gateway bot-link
+# :9443 the remote bot dials in over mTLS; and (2) retunes the R7 limits down for the
+# 2 vCPU / 1.9 GiB host (GOMAXPROCS=2, smaller memory caps, shorter Prometheus
+# retention). The contour launches deliberately undersized at zero players; the added
+# node_exporter + Grafana watch host memory so it can be resized at Selectel when
+# traffic arrives.
+#
+# The bot + its VPN sidecar are absent here (the telegram-local profile is not
+# activated); the prod bot runs on its own host from docker-compose.bot.yml.
+
+services:
+  caddy:
+    ports:
+      - "80:80"
+      - "443:443"
+    deploy:
+      resources:
+        limits:
+          memory: 96M
+
+  gateway:
+    # Prod pulls the pushed image by tag instead of building locally; the base
+    # build: section stays dormant because the deploy always pulls first.
+    image: ${REGISTRY:?set REGISTRY}/scrabble-gateway:${TAG:?set TAG}
+    ports:
+      - "9443:9443"
+    environment:
+      # 2 vCPU host: align the Go scheduler with the cgroup quota (R7's 3 needs 3 cores).
+      GOMAXPROCS: "2"
+    deploy:
+      resources:
+        limits:
+          cpus: "2.0"
+          memory: 384M
+
+  backend:
+    image: ${REGISTRY:?set REGISTRY}/scrabble-backend:${TAG:?set TAG}
+    deploy:
+      resources:
+        limits:
+          memory: 384M
+
+  postgres:
+    deploy:
+      resources:
+        limits:
+          memory: 384M
+
+  validator:
+    image: ${REGISTRY:?set REGISTRY}/scrabble-telegram-validator:${TAG:?set TAG}
+    deploy:
+      resources:
+        limits:
+          memory: 96M
+
+  landing:
+    image: ${REGISTRY:?set REGISTRY}/scrabble-landing:${TAG:?set TAG}
+    deploy:
+      resources:
+        limits:
+          memory: 64M
+
+  otelcol:
+    deploy:
+      resources:
+        limits:
+          memory: 256M
+
+  prometheus:
+    command:
+      - --config.file=/etc/prometheus/prometheus.yml
+      - --storage.tsdb.retention.time=7d
+    deploy:
+      resources:
+        limits:
+          memory: 256M
+
+  tempo:
+    deploy:
+      resources:
+        limits:
+          memory: 384M
+
+  grafana:
+    deploy:
+      resources:
+        limits:
+          memory: 256M
+
+  postgres_exporter:
+    deploy:
+      resources:
+        limits:
+          memory: 64M

deploy/docker-compose.yml

@@ -71,6 +71,8 @@ services:
         # Seed dictionary for a FRESH volume; the per-contour value comes from the
         # deploy env (Gitea TEST_/PROD_DICT_VERSION). See the volume note below.
         DICT_VERSION: ${DICT_VERSION:-v1.2.1}
+        # Build version stamped into the binary (git tag; see pkg/version).
+        VERSION: ${APP_VERSION:-dev}
     restart: unless-stopped
     logging: *default-logging
     depends_on:
@@ -132,6 +134,8 @@ services:
         VITE_TELEGRAM_GAME_CHANNEL_NAME: ${VITE_TELEGRAM_GAME_CHANNEL_NAME:-}
         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).
+        VERSION: ${APP_VERSION:-dev}
     restart: unless-stopped
     logging: *default-logging
     depends_on: [backend]
@@ -218,6 +222,8 @@ services:
       context: ..
       dockerfile: platform/telegram/Dockerfile
       target: validator
+      args:
+        VERSION: ${APP_VERSION:-dev}
     restart: unless-stopped
     logging: *default-logging
     environment:
@@ -240,14 +246,22 @@ services:
     networks: [internal]
 
   # --- Telegram bot (egress via the VPN sidecar in test; dials the gateway) ---
+  # vpn + bot are gated to the `telegram-local` profile: the test contour runs them
+  # locally (CI passes --profile telegram-local), the prod main host omits them, and
+  # the prod bot runs on its own host from deploy/docker-compose.bot.yml.
   vpn:
     container_name: scrabble-telegram-vpn
     image: docker.iliadenisov.ru/developer/amneziawg-sidecar:latest
+    profiles: ["telegram-local"]
     restart: unless-stopped
     logging: *default-logging
     privileged: true
     environment:
-      AWG_CONF: ${AWG_CONF:?set AWG_CONF}
+      # Required by the vpn sidecar, which is gated to the telegram-local profile.
+      # Compose can't scope a `:?` guard to a profile (interpolation runs for
+      # profiled-out services too) and the prod main host has no VPN, so this is a soft
+      # default; the test contour always supplies TEST_AWG_CONF and the sidecar validates it.
+      AWG_CONF: ${AWG_CONF:-}
     networks:
       internal:
         aliases: [telegram]
@@ -255,10 +269,13 @@ services:
   bot:
     container_name: scrabble-telegram-bot
     image: scrabble-telegram-bot:latest
+    profiles: ["telegram-local"]
     build:
       context: ..
       dockerfile: platform/telegram/Dockerfile
       target: bot
+      args:
+        VERSION: ${APP_VERSION:-dev}
     restart: unless-stopped
     logging: *default-logging
     depends_on: [vpn]
@@ -268,6 +285,17 @@ services:
       # at boot; an empty value leaves the bot down while the rest of the contour comes up.
       TELEGRAM_BOT_TOKEN: ${TELEGRAM_BOT_TOKEN:-}
       TELEGRAM_GAME_CHANNEL_ID: ${TELEGRAM_GAME_CHANNEL_ID:-}
+      # The moderated discussion chat (a channel's linked group) the bot gates write
+      # access in. Empty disables gating. The group must ALLOW sending by default — the bot
+      # only restricts (mutes the ineligible) — and the bot must be an admin there with the
+      # "Ban users" right; chat_member updates are delivered only to a chat admin.
+      TELEGRAM_CHAT_ID: ${TELEGRAM_CHAT_ID:-}
+      # The optional standalone promo bot (its own token) answering /start with a button
+      # into the main bot's app. Empty disables it; when set it needs the main bot's
+      # @username and the Mini App link (reused from the UI's VITE_TELEGRAM_LINK).
+      TELEGRAM_PROMO_BOT_TOKEN: ${TELEGRAM_PROMO_BOT_TOKEN:-}
+      TELEGRAM_BOT_USERNAME: ${TELEGRAM_BOT_USERNAME:-}
+      TELEGRAM_BOT_LINK: ${TELEGRAM_BOT_LINK:-}
       TELEGRAM_MINIAPP_URL: ${TELEGRAM_MINIAPP_URL:?set TELEGRAM_MINIAPP_URL}
       TELEGRAM_TEST_ENV: ${TELEGRAM_TEST_ENV:-false}
       TELEGRAM_API_BASE_URL: ${TELEGRAM_API_BASE_URL:-}
@@ -433,6 +461,26 @@ services:
           memory: 128M
     networks: [internal]
 
+  # node_exporter exports host CPU/memory/disk metrics. The prod main host runs a tight
+  # 1.9 GiB budget, so host memory pressure — not just per-container docker_stats — is
+  # what warns before an OOM. Prometheus scrapes it at :9100 (see prometheus.yml).
+  node_exporter:
+    container_name: scrabble-node-exporter
+    image: quay.io/prometheus/node-exporter:v1.8.2
+    restart: unless-stopped
+    logging: *default-logging
+    command:
+      - --path.rootfs=/host
+      - --collector.filesystem.mount-points-exclude=^/(sys|proc|dev|host)($|/)
+    pid: host
+    volumes:
+      - /:/host:ro,rslave
+    deploy:
+      resources:
+        limits:
+          memory: 64M
+    networks: [internal]
+
 networks:
   internal:
     name: scrabble-internal

deploy/prod-deploy.sh

@@ -0,0 +1,143 @@
+#!/usr/bin/env bash
+# Production main-host deploy driver. Runs ON the main host, invoked over SSH by
+# .gitea/workflows/prod-deploy.yaml as the deploy user (which must already be
+# `docker login`ed to the registry). It pulls the images at the new tag and rolls
+# the stack ONE service at a time in dependency order (least -> most dependent),
+# health-checking after each; any failure rolls the whole stack back to the
+# previously deployed tag.
+#
+# A schema migration adds a maintenance window: the backend (the only writer) is
+# stopped so a consistent pg_dump is taken before the new backend migrates forward.
+# Image rollback alone is safe under the expand-contract migration rule, so the
+# automatic rollback never touches the database; the dump is kept for a MANUAL
+# restore if a migration turned out to be destructive (see deploy/prod/README.md).
+#
+# Required env (exported by the workflow over SSH):
+#   REGISTRY   registry namespace, e.g. docker.iliadenisov.ru/developer
+#   TAG        new image tag (the deployed git SHA)
+#   PREV_TAG   previously deployed tag, or "none" on the first deploy
+#   MIGRATION  "1" when the deploy carries a schema migration, else "0"
+# Optional: COMPOSE_DIR ENV_FILE DUMP_DIR STATE_FILE POSTGRES_USER POSTGRES_DB
+set -uo pipefail
+
+# Runtime compose vars (POSTGRES_*, GM_*, GRAFANA_*, CADDY_*, TELEGRAM_*, REGISTRY,
+# SCRABBLE_CONFIG_DIR, ...) come from a shell-sourceable env file the workflow writes
+# with single-quoted values. Exporting them into the process environment lets compose
+# interpolate ${...} without re-parsing the value — a plain --env-file would mangle the
+# literal '$' in the bcrypt GM_BASICAUTH_HASH.
+ENV_FILE="${ENV_FILE:-/opt/scrabble/env.sh}"
+# shellcheck disable=SC1090
+[ -f "$ENV_FILE" ] && . "$ENV_FILE"
+
+REGISTRY="${REGISTRY:?REGISTRY required (env.sh)}"
+TAG="${TAG:?TAG required}"
+PREV_TAG="${PREV_TAG:-none}"
+MIGRATION="${MIGRATION:-0}"
+COMPOSE_DIR="${COMPOSE_DIR:-/opt/scrabble/compose}"
+DUMP_DIR="${DUMP_DIR:-/opt/scrabble/dumps}"
+STATE_FILE="${STATE_FILE:-/opt/scrabble/DEPLOYED_TAG}"
+# The prior deployed tag, preserved on every successful deploy so prod-rollback can
+# target "the previous version" with no operator input.
+PREV_STATE_FILE="${PREV_STATE_FILE:-/opt/scrabble/PREVIOUS_TAG}"
+PG_USER="${POSTGRES_USER:-scrabble}"
+PG_DB="${POSTGRES_DB:-scrabble}"
+
+cd "$COMPOSE_DIR" || { echo "compose dir $COMPOSE_DIR missing"; exit 1; }
+export REGISTRY
+# otelcol joins the host docker group to read the socket; the GID varies per host.
+DOCKER_GID="$(getent group docker | cut -d: -f3)"
+export DOCKER_GID
+
+dc() { docker compose -f docker-compose.yml -f docker-compose.prod.yml "$@"; }
+use_tag() { export TAG="$1"; }
+
+# --- health probes (one-off containers on the contour networks, like CI) --------
+_probe() { docker run --rm --network "$1" alpine:3.20 wget -q -T 5 -O /dev/null "$2"; }
+health_backend() { for _ in $(seq 1 20); do _probe scrabble-internal http://backend:8080/readyz && return 0; sleep 3; done; return 1; }
+health_landing() { for _ in $(seq 1 20); do _probe scrabble-internal http://landing:80/ && return 0; sleep 3; done; return 1; }
+health_postgres() { for _ in $(seq 1 30); do [ "$(docker inspect -f '{{.State.Health.Status}}' scrabble-postgres 2>/dev/null)" = healthy ] && return 0; sleep 2; done; return 1; }
+health_running() { # health_running <container>: running, not restarting, stable restart count
+  local n="$1" s r c1 c2
+  for _ in $(seq 1 20); do
+    s="$(docker inspect -f '{{.State.Status}}' "$n" 2>/dev/null || echo missing)"
+    r="$(docker inspect -f '{{.State.Restarting}}' "$n" 2>/dev/null || echo true)"
+    if [ "$s" = running ] && [ "$r" = false ]; then
+      c1="$(docker inspect -f '{{.RestartCount}}' "$n")"; sleep 5
+      c2="$(docker inspect -f '{{.RestartCount}}' "$n")"
+      [ "$c1" = "$c2" ] && return 0
+    fi
+    sleep 3
+  done
+  return 1
+}
+
+roll() { # roll <service> <health-cmd...>
+  local svc="$1"; shift
+  echo ">>> rolling $svc -> $TAG"
+  dc up -d --no-build --no-deps "$svc" || return 1
+  "$@" || { echo "!!! $svc failed health check"; return 1; }
+  echo "<<< $svc healthy"
+}
+
+rollback() {
+  echo "########## ROLLBACK -> $PREV_TAG ##########"
+  if [ "$PREV_TAG" = none ]; then
+    echo "no previous tag (first deploy): cannot roll back; leaving the stack up for inspection."
+    return
+  fi
+  use_tag "$PREV_TAG"
+  dc up -d --no-build --remove-orphans
+  echo "rolled back to $PREV_TAG."
+  [ "$MIGRATION" = 1 ] && echo "NOTE: the DB is forward-migrated; a pre-deploy dump is in $DUMP_DIR — restore manually ONLY if the migration was destructive (see deploy/README.md, prod runbook)."
+}
+
+commit_tag() {
+  # Record the just-deployed tag as current, preserving the prior one as previous.
+  [ -f "$STATE_FILE" ] && cp "$STATE_FILE" "$PREV_STATE_FILE"
+  echo "$TAG" > "$STATE_FILE"
+}
+
+mkdir -p "$DUMP_DIR"
+echo "=== prod deploy: tag=$TAG prev=$PREV_TAG migration=$MIGRATION ==="
+use_tag "$TAG"
+dc pull
+
+# First deploy: nothing to roll from; bring the whole stack up and gate on health.
+if [ -z "$(docker ps -aq -f name=scrabble-backend)" ]; then
+  echo "first deploy: bringing the whole stack up"
+  dc up -d --no-build --remove-orphans || { echo "compose up failed"; exit 1; }
+  health_backend || { echo "backend not ready"; exit 1; }
+  health_landing || { echo "landing not ready"; exit 1; }
+  commit_tag
+  echo "first deploy healthy ($TAG)."
+  exit 0
+fi
+
+# Migration deploy: freeze writes and snapshot a consistent dump before migrating.
+if [ "$MIGRATION" = 1 ]; then
+  echo "migration deploy: opening maintenance window (stopping the backend = the only writer)"
+  dc stop backend
+  dump="$DUMP_DIR/pre-$TAG-$(date +%Y%m%d-%H%M%S).sql"
+  if ! docker exec scrabble-postgres pg_dump -U "$PG_USER" -d "$PG_DB" -n backend > "$dump"; then
+    echo "pg_dump failed; restarting the old backend and aborting"
+    dc start backend
+    exit 1
+  fi
+  echo "consistent dump: $dump"
+fi
+
+# Roll one service at a time, least -> most dependent; any failure rolls everything back.
+roll postgres  health_postgres                              || { rollback; exit 1; }
+roll backend   health_backend                               || { rollback; exit 1; }
+roll gateway   health_running scrabble-gateway              || { rollback; exit 1; }
+roll landing   health_landing                               || { rollback; exit 1; }
+roll validator health_running scrabble-telegram-validator   || { rollback; exit 1; }
+roll caddy     health_running scrabble-caddy                || { rollback; exit 1; }
+
+# Observability + node_exporter: bring up the remainder and pick up any config changes.
+dc up -d --no-build --remove-orphans || { rollback; exit 1; }
+
+# Final internal sanity before committing the new tag.
+health_backend || { rollback; exit 1; }
+commit_tag
+echo "=== deploy healthy ($TAG) ==="

deploy/prometheus/prometheus.yml

@@ -18,3 +18,8 @@ scrape_configs:
   - job_name: postgres_exporter
     static_configs:
       - targets: ["postgres_exporter:9187"]
+  # Host-level metrics (memory/CPU/disk). Matters most on the prod main host's tight
+  # 1.9 GiB budget, where total host memory is the OOM-proximity signal.
+  - job_name: node
+    static_configs:
+      - targets: ["node_exporter:9100"]

docs/ARCHITECTURE.md

@@ -128,7 +128,11 @@ dropped). Horizontal scaling is explicit future work.
   and GCG are unaffected** (they stay decoded concrete characters, §9.1).
 - **gateway ↔ backend (sync)**: plain HTTP REST/JSON. The gateway injects
   `X-User-ID` for authenticated requests; `backend` never re-derives identity
-  from the body.
+  from the body. Because every sync call targets the one backend host, the
+  gateway's REST client widens its keep-alive pool well past the stdlib default
+  of 2 idle connections per host; otherwise the per-request connection churn
+  exhausts ephemeral ports and burns gateway CPU under load (see
+  [`../loadtest/REPORT.md`](../loadtest/REPORT.md)).
 - **backend → gateway (live)**: a single gRPC server-stream carries live events
   (your-turn, opponent-moved, chat, nudge). The gateway bridges them to the
   client's in-app stream while the app is open. Out-of-app delivery uses
@@ -824,7 +828,13 @@ the bot renders the message and skips the rest — so in-app-only sub-kinds like
 block-state sync to the blocker) never become a platform push. Operator broadcasts
 (`SendToUser` / `SendToGameChannel`, §10 admin) render in an **operator-chosen** language in
 the console; the backend calls them on the **gateway's bot-link relay**, which forwards them
-to the bot and **awaits its delivery ack** (so the console still reports delivered/not).
+to the bot and **awaits its delivery ack** (so the console still reports delivered/not). Beyond
+messages the same bot-link carries a **chat-gate control path** — a `ChatGate` command sets a user's
+write access in the moderated discussion chat and the bot's unary `ResolveChatEligibility` resolves a
+joiner's eligibility (neither renders a message; see *Moderated discussion chat* below). An optional
+**standalone promo bot** runs in the bot container (`TELEGRAM_PROMO_BOT_TOKEN`): a second bot
+answering `/start` with a URL button into the **main** bot's Mini App (`?startapp`, since a `web_app`
+button would sign initData with the promo token); it is self-contained — no bot-link, no gateway.
 Session-revocation events and cursor-based stream resume stay deferred (single-instance MVP).
 
 A separate **advertising-banner** channel feeds the client's one-line strip (UI_DESIGN.md),
@@ -987,9 +997,28 @@ revoked token would fail session resolution at the gateway *before* the gate, se
 login instead of the blocked screen). A block instantly **forfeits** every active game the player
 is in (the opponent wins, exactly as a resignation — the engine resigns off-turn) and cancels
 their open matchmaking games; a temporary block lapses automatically once its expiry passes (no
-sweeper — the gate recomputes against `now`). No operator identity is recorded (shared
+sweeper for the gate — it recomputes against `now`). No operator identity is recorded (shared
 Basic-Auth).
 
+**Moderated discussion chat.** A channel's linked discussion group is gated by the Telegram bot
+(`TELEGRAM_CHAT_ID`). The group **allows sending by default** and the bot only **restricts**: Telegram
+intersects the chat default with each user's permission, so a per-user grant can never exceed a
+deny-by-default group — the gate must mute the ineligible, not grant the eligible. A user may write
+while they are **registered and neither admin-suspended nor holding the chat-only `chat_muted` role**
+(`eligible = registered AND NOT suspended AND NOT chat_muted` — the game suspension dominates); the bot
+**mutes** an ineligible member and **un-mutes** an eligible one it had muted, leaving an already-allowed
+eligible member untouched (it acts only when the current state differs, so it is idempotent and never
+loops on its own change). A single backend resolver behind `POST /api/v1/internal/chat-access` answers
+both directions: the bot's `ResolveChatEligibility` on a `chat_member` event (over the mTLS bot-link),
+and a `chat_access_changed` event — emitted on a block/unblock, a `chat_muted` grant/revoke, a first
+Telegram registration, or a temporary block lapsing (a dedicated `account.SuspensionSweeper`, since no
+request fires then) — drives a `ChatGate` command the gateway pushes to the bot. The bot applies it
+only to a member currently in the chat (a per-user `getChatMember` probe, since bots cannot list
+members); the signal is idempotent and is never an in-app or out-of-app message. `chat_muted` is an
+`account_roles` entry (an operator toggle in the console), so it needs no schema change. The bot
+must be an administrator in the group with the **restrict-members** right and `chat_member` in its
+allowed updates.
+
 **Short numeric codes** (email confirm-codes and friend codes) are stored
 only as SHA-256 hashes and are short-lived and single-use. The unauthenticated
 email path carries a tight per-IP sub-limit (5 / 10 min); the **friend-code redeem**
@@ -1027,8 +1056,10 @@ plaintext relay (`GATEWAY_BOTLINK_RELAY_ADDR`) the backend admin console calls.
 
 The full contour (`deploy/docker-compose.yml`) runs one `gateway`, one `backend`,
 one Postgres, the static `landing`, the Telegram `validator` and `bot` (+ the bot's VPN
-sidecar) and the **observability stack** —
-OTel Collector (OTLP/gRPC ingest → Prometheus metrics + Tempo traces) and Grafana
+sidecar — the `bot`+`vpn` pair is gated to a `telegram-local` compose profile so the prod
+main host can omit them) and the **observability stack** —
+OTel Collector (OTLP/gRPC ingest → Prometheus metrics + Tempo traces), a `node_exporter`
+for host CPU/memory (the prod main host's OOM signal), and Grafana
 with provisioned datasources and dashboards. All services export OTLP to the
 collector; the bot shares the VPN sidecar's netns, so its `AWG_CONF` must not
 carry a `DNS=` directive (that would hijack resolv.conf and stop it resolving
@@ -1052,16 +1083,36 @@ Two contours, two secret/variable prefixes (`TEST_` / `PROD_`):
   generated by `deploy/gen-certs.sh` before `compose up`; the bot keeps its VPN sidecar
   for Telegram egress and dials the gateway by its internal name, so the bot-link stays
   on the internal network.
-- **Prod**: a manual SSH deploy after `development → master`. There is no
-  host caddy, so the contour ships its own caddy terminating TLS — set
-  `CADDY_SITE_ADDRESS` to the domain and the caddy does its own ACME. The **bot runs
-  on a separate host** with native Telegram access (no VPN), deployed by SSH alongside
-  the main app (rolled together so the bot-link protocol versions never skew); the
-  gateway **publishes** the bot-link port and the certificates come from `PROD_`
-  secrets — a long-lived CA with leaves rotated by a scheduled job. The bot dials the
-  gateway's public bot-link endpoint and holds no inbound port; login is unaffected if
-  that host or the link is down. *(This prod wiring is the deferred final stage; the
-  code and the unified test contour land first — see `PRERELEASE.md`.)*
+- **Prod**: a **manual** rollout — `.gitea/workflows/prod-deploy.yaml`, `workflow_dispatch`
+  only (from `master`, `confirm=deploy`), run after `development → master` is merged green.
+  It builds and pushes the images to the registry (`docker.iliadenisov.ru`), then deploys
+  over SSH onto **two hosts** provisioned by `deploy/ansible/` (docker, a non-sudo `deploy`
+  service account holding a dedicated CI key, key-only sshd, default-deny ufw, fail2ban):
+  the **main host** runs the full stack (`docker-compose.yml` + `docker-compose.prod.yml`),
+  the **bot host** runs only the bot (`docker-compose.bot.yml`, no VPN — native Bot API
+  egress, telemetry off). There is no host caddy, so the contour caddy terminates TLS —
+  `CADDY_SITE_ADDRESS` is the domain and caddy does its own ACME. The gateway **publishes**
+  the bot-link `:9443`; the remote bot dials it over mTLS (certs from `PROD_BOTLINK_*`,
+  ServerName `gateway`, so TLS validation is independent of the public dial address), holds
+  no inbound port, and login is unaffected if that host or the link is down.
+  `deploy/prod-deploy.sh` rolls the main stack **one service at a time in dependency order**
+  (postgres → backend → gateway → landing → validator → caddy), health-checking after each;
+  any failure **rolls the whole stack back to the previous image tag**. A **schema migration**
+  adds a maintenance window: the backend (the sole writer) is stopped for a consistent
+  `pg_dump` before the new backend migrates forward — image rollback stays DB-safe under the
+  expand-contract migration rule, and the dump is kept for a manual restore. The workflow runs
+  four visible jobs (build → deploy-main → deploy-bot → verify). Releases are git tags
+  `vX.Y.Z`; the version is stamped into the image tag, every binary (`-ldflags` → `pkg/version`
+  → the `service.version` telemetry attribute) and the SPA About screen. A separate manual
+  **`prod-rollback`** workflow re-deploys any prior release tag (blank input = the previous
+  deployed version, tracked on the host) over the same rolling, health-gated path — image-only,
+  no DB migration. The main host is
+  intentionally **launch-sized** (2 vCPU / 1.9 GiB): the prod overlay trims the R7 limits
+  (`GOMAXPROCS=2`, smaller caps, 7d Prometheus retention) and a **node_exporter** feeds
+  host-memory metrics to Grafana so it can be resized reactively as players arrive.
+  `GATEWAY_ABUSE_BAN_ENABLED=true` in prod (the per-IP ban is meaningful only with real
+  client IPs). The `vpn`+`bot` pair is gated to a `telegram-local` compose profile the test
+  contour activates; the prod main host omits it.
 
 ## 14. CI & branches
 

docs/FUNCTIONAL.md

@@ -31,9 +31,15 @@ ephemeral guest. The gateway validates the credential once and mints a thin
 session token; the backend resolves it to an internal `user_id`. A **Telegram Mini
 App** launch authenticates from the platform's signed `initData`, themes the UI to
 the Telegram colours, and — on first contact — seeds the new account's interface
-language from the Telegram client. Telegram runs a **single bot**: every player uses
+language from the Telegram client. If a launch cannot reach the backend (for example during a
+deployment), the Mini App retries quietly and then shows a small "couldn't load" screen with a
+**Retry** button, rather than dropping to the web sign-in, which has no place inside Telegram.
+Telegram runs a **single bot**: every player uses
 the same bot, and all of its chat and out-of-app notifications are written in the
-player's own **interface language** (en/ru). Guests are session-only with restricted features
+player's own **interface language** (en/ru). A separate optional **promo bot** can run alongside the
+main one — its only job is to answer `/start` with a short message and a button that opens the
+**main** bot's app, where the player picks their game variant; it is an onboarding entry point that
+touches nothing else. Guests are session-only with restricted features
 (auto-match only; no friends, stats or history); an abandoned guest that never
 joined a game and has been idle past the retention window is garbage-collected. While the app is open the client
 keeps a live stream and receives in-app updates in real time — the opponent's move,
@@ -53,6 +59,10 @@ 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
@@ -320,6 +330,14 @@ plus the reason when one was given, and the app stops all background traffic wit
 temporary block lifts itself when it expires; the operator can also **unblock** from the user card
 at any time (games already lost stay lost).
 
+Where the bot manages a channel's **linked discussion chat**, everyone may write by default and the
+bot **mutes** a player who is **not registered** or is **blocked**, un-muting them once they register
+or are unblocked. So an unregistered newcomer who comments is muted (the promo bot points them at the
+game to register, after which the bot restores their voice), and a registered, unblocked player simply
+writes. An operator can also **mute a player in the chat only** — a `chat_muted` role on the user card —
+without a full account block; an account block mutes them in the chat regardless. Muting and unmuting
+take effect for a player already in the chat; one who is not in it is unaffected until they next join.
+
 From the user card the operator can also **top up a player's hint wallet**: an additive grant
 (1–100 hints per action) that raises the balance shown on the card. Grants are **raise-only** —
 the console can never lower a wallet (a player only loses hints by spending them in a game), so an

docs/FUNCTIONAL_ru.md

@@ -32,9 +32,15 @@ top-1 подсказку, безлимитную проверку слова с
 session-токен; backend сопоставляет его с внутренним `user_id`. Запуск **Telegram
 Mini App** авторизует по подписанным `initData` платформы, перекрашивает интерфейс
 в цвета Telegram и — при первом контакте — задаёт язык интерфейса нового аккаунта по
-языку Telegram-клиента. Telegram держит **единого бота**: все игроки пользуются одним
+языку Telegram-клиента. Если запуск не может достучаться до бэкенда (например, во время
+деплоя), Mini App тихо повторяет попытки, а затем показывает небольшой экран «не удалось
+загрузить» с кнопкой **Повторить**, вместо того чтобы сбрасывать на веб-вход, которому внутри
+Telegram не место. Telegram держит **единого бота**: все игроки пользуются одним
 и тем же ботом, а весь его чат и внеприложенческие уведомления пишутся на **языке
-интерфейса** самого игрока (en/ru). Гость — только сессия, с урезанными функциями (только
+интерфейса** самого игрока (en/ru). Рядом с основным может работать отдельный опциональный
+**промо-бот** — его единственная задача отвечать на `/start` коротким сообщением и кнопкой,
+открывающей приложение **основного** бота, где игрок выбирает нужный вариант игры; это точка входа
+для онбординга, не затрагивающая больше ничего. Гость — только сессия, с урезанными функциями (только
 авто-подбор; без друзей, статистики и истории); заброшенный гость, не вошедший ни
 в одну игру и простаивавший дольше окна удержания, удаляется сборщиком. Пока приложение открыто, клиент
 держит живой стрим и получает обновления в реальном времени — ход соперника, ваш ход,
@@ -54,6 +60,10 @@ Mini App** авторизует по подписанным `initData` плат
 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
@@ -329,6 +339,15 @@ high-rate флага. С карточки пользователя операт
 истечении срока; оператор также может **разблокировать** с карточки пользователя в любой момент
 (уже проигранные партии не возвращаются).
 
+Там, где бот ведёт **привязанный к каналу чат-обсуждение**, по умолчанию писать может каждый, а бот
+**глушит** игрока, который **не зарегистрирован** или **заблокирован**, и снимает мьют, как только тот
+зарегистрируется или будет разблокирован. То есть незарегистрированного новичка, написавшего в чат,
+бот глушит (промо-бот направляет его в игру зарегистрироваться, после чего бот возвращает голос), а
+зарегистрированный незаблокированный игрок просто пишет. Оператор также может **замьютить игрока только
+в чате** — роль `chat_muted` на карточке пользователя — без полной блокировки аккаунта; блокировка
+аккаунта всё равно мьютит его в чате. Мьют и размьют срабатывают для игрока, уже находящегося в чате;
+того, кого в чате нет, это не затрагивает до его следующего входа.
+
 С карточки пользователя оператор также может **пополнить кошелёк подсказок** игрока: аддитивное
 начисление (1–100 подсказок за раз), которое **только увеличивает** баланс на карточке. Начисления
 **только в плюс** — понизить кошелёк из консоли нельзя (игрок теряет подсказки только тратя их в

docs/TESTING.md

@@ -133,9 +133,9 @@ tests or touching CI.
   engine tests do). It is **not** part of the per-PR suite's behavioural assertions: it
   runs ad hoc as a one-shot container against the contour, producing a trip report (bugs
   + a per-container resource profile) read off the **otelcol `docker_stats` +
-  postgres_exporter** Grafana dashboard on the contour. Two passes are recorded — the
-  early [`REPORT-R2.md`](../loadtest/REPORT-R2.md) and the final, tuned
-  [`REPORT-R7.md`](../loadtest/REPORT-R7.md). See [`../loadtest/README.md`](../loadtest/README.md).
+  postgres_exporter** Grafana dashboard on the contour. The findings — including the
+  `game.evaluate` hot-path model and the gateway→backend connection-pool fix — are written
+  up in [`REPORT.md`](../loadtest/REPORT.md). See [`../loadtest/README.md`](../loadtest/README.md).
 - **User feedback** — `internal/feedback` unit tests cover the attachment allow-list /
   content-type and the channel normaliser; the UI covers `detectChannel`, the attachment gate and
   the feedback wire round-trip (`channel` / `feedback` / `codec` tests) plus a Playwright e2e

gateway/Dockerfile

@@ -70,7 +70,9 @@ RUN rm gateway/internal/webui/dist/landing.html
 # Reduce the workspace to what the gateway needs: gateway + pkg (loadtest is not in
 # this context; its scrabble/gateway replace targets ./gateway, which is present here).
 RUN go work edit -dropuse=./backend -dropuse=./platform/telegram -dropuse=./loadtest
-RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -o /out/gateway ./gateway/cmd/gateway
+# VERSION (the deploy passes the git tag) is stamped into the binary via the linker.
+ARG VERSION=dev
+RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -ldflags "-X scrabble/pkg/version.Version=${VERSION}" -o /out/gateway ./gateway/cmd/gateway
 
 # --- runtime -----------------------------------------------------------------
 FROM gcr.io/distroless/static-debian12:nonroot AS gateway

gateway/cmd/gateway/main.go

@@ -147,7 +147,11 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 	// fire-and-forget; the backend admin relay (plaintext, internal) awaits the Ack.
 	var botHub *botlink.Hub
 	if cfg.BotLinkEnabled() {
-		botHub = botlink.NewHub(logger, tel.MeterProvider().Meter("scrabble/gateway/botlink"))
+		botHub = botlink.NewHub(logger, tel.MeterProvider().Meter("scrabble/gateway/botlink"),
+			func(ctx context.Context, externalID string) (bool, bool, error) {
+				r, rerr := backend.ChatEligibility(ctx, externalID)
+				return r.Registered, r.Eligible, rerr
+			})
 		tlsCfg, terr := mtls.ServerConfig(cfg.BotLink.CertFile, cfg.BotLink.KeyFile, cfg.BotLink.CAFile)
 		if terr != nil {
 			return terr
@@ -361,6 +365,15 @@ func runPushPump(ctx context.Context, backend *backendclient.Client, hub *push.H
 				}
 				break
 			}
+			// A chat-access-changed event is an infra signal, not an in-app event:
+			// resolve the recipient's Telegram identity and current eligibility and
+			// push the chat-gate command to the bot, without fanning it out to clients.
+			if ev.GetKind() == chatAccessChangedKind {
+				if bot != nil {
+					go deliverChatGate(ctx, backend, bot, ev.GetUserId(), logger)
+				}
+				continue
+			}
 			hub.Publish(push.Event{
 				UserID:  ev.GetUserId(),
 				Kind:    ev.GetKind(),
@@ -398,6 +411,27 @@ func deliverOutOfApp(ctx context.Context, backend *backendclient.Client, bot *bo
 	bot.Send(botlink.NotifyCommand(target.ExternalID, kind, payload, target.Language))
 }
 
+// chatAccessChangedKind is the backend event signalling that a player's moderated-chat
+// write eligibility may have changed; the gateway turns it into a bot-link chat-gate
+// command rather than an in-app event (it mirrors notify.KindChatAccessChanged).
+const chatAccessChangedKind = "chat_access_changed"
+
+// deliverChatGate resolves a chat-access-changed event to the recipient's Telegram
+// identity and current eligibility and pushes the chat-gate command to the bot. It is
+// best-effort: a recipient with no Telegram identity is skipped, and a resolve failure
+// is logged and dropped (the next moderation action, or a re-join, re-applies the gate).
+func deliverChatGate(ctx context.Context, backend *backendclient.Client, bot *botlink.Hub, userID string, logger *zap.Logger) {
+	res, err := backend.ChatAccessByUser(ctx, userID)
+	if err != nil {
+		logger.Warn("chat-gate resolve failed", zap.String("user_id", userID), zap.Error(err))
+		return
+	}
+	if res.ExternalID == "" {
+		return // no Telegram identity, nothing to gate
+	}
+	bot.Send(botlink.ChatGateCommand(res.ExternalID, res.Eligible))
+}
+
 // sleep waits for d or until ctx is cancelled, reporting whether it waited the
 // full duration.
 func sleep(ctx context.Context, d time.Duration) bool {

gateway/internal/backendclient/api.go

@@ -215,6 +215,34 @@ func (c *Client) PushTarget(ctx context.Context, userID string) (PushTargetResp,
 	return out, err
 }
 
+// ChatAccessResp is a user's moderated-chat write eligibility: ExternalID is their
+// Telegram identity (empty when they have none, so the gateway has nothing to gate),
+// Registered whether an account was found, and Eligible the final gate the bot applies
+// (registered and neither admin-suspended nor chat-muted).
+type ChatAccessResp struct {
+	ExternalID string `json:"external_id"`
+	Registered bool   `json:"registered"`
+	Eligible   bool   `json:"eligible"`
+}
+
+// ChatEligibility resolves a Telegram identity to its moderated-chat write
+// eligibility — the join path, when the bot sees a user enter the chat.
+func (c *Client) ChatEligibility(ctx context.Context, externalID string) (ChatAccessResp, error) {
+	var out ChatAccessResp
+	err := c.do(ctx, http.MethodPost, "/api/v1/internal/chat-access", "", "",
+		map[string]string{"external_id": externalID}, &out)
+	return out, err
+}
+
+// ChatAccessByUser resolves an account id to its Telegram identity and current
+// moderated-chat write eligibility — the change path, for a chat-access-changed event.
+func (c *Client) ChatAccessByUser(ctx context.Context, userID string) (ChatAccessResp, error) {
+	var out ChatAccessResp
+	err := c.do(ctx, http.MethodPost, "/api/v1/internal/chat-access", "", "",
+		map[string]string{"user_id": userID}, &out)
+	return out, err
+}
+
 // GuestAuth provisions a guest account and mints a session.
 func (c *Client) GuestAuth(ctx context.Context) (SessionResp, error) {
 	var out SessionResp

gateway/internal/backendclient/client.go

@@ -22,6 +22,19 @@ import (
 	pushv1 "scrabble/pkg/proto/push/v1"
 )
 
+// backendMaxIdleConns sizes the REST keep-alive pool to the single backend host. The
+// default transport caps idle connections per host at 2 (http.DefaultMaxIdleConnsPerHost),
+// which — since every synchronous client call proxies to that one host — forces a fresh
+// TCP connection (and a lingering TIME_WAIT socket) for almost every request under load.
+// That connection churn burns gateway CPU and exhausts ephemeral ports at scale, all
+// while the backend itself sits near-idle. Pooling the connections lets them be reused.
+//
+// The stress harness measured the effect at 500 concurrent players: the churn collapsed
+// from ~26 500 TIME_WAIT sockets to ~0 and peak gateway CPU from ~1.75 to ~0.26 cores,
+// with the pool settling at ~225 live connections. 512 keeps ~2x headroom over that
+// observed peak so a burst never re-caps the pool. See loadtest/REPORT.md.
+const backendMaxIdleConns = 512
+
 // Client calls the backend's REST API and opens its push gRPC stream.
 type Client struct {
 	baseURL string
@@ -41,9 +54,14 @@ func New(httpURL, grpcAddr string, timeout time.Duration) (*Client, error) {
 	if err != nil {
 		return nil, fmt.Errorf("backendclient: dial push %s: %w", grpcAddr, err)
 	}
+	// Clone the default transport (keeping its proxy, dialer and timeouts) and widen the
+	// idle pool so REST calls to the backend reuse connections instead of churning them.
+	transport := http.DefaultTransport.(*http.Transport).Clone()
+	transport.MaxIdleConns = backendMaxIdleConns
+	transport.MaxIdleConnsPerHost = backendMaxIdleConns
 	return &Client{
 		baseURL: strings.TrimRight(httpURL, "/"),
-		http:    &http.Client{Timeout: timeout},
+		http:    &http.Client{Timeout: timeout, Transport: transport},
 		conn:    conn,
 		push:    pushv1.NewPushClient(conn),
 	}, nil

gateway/internal/backendclient/client_internal_test.go

@@ -0,0 +1,31 @@
+package backendclient
+
+import (
+	"net/http"
+	"testing"
+	"time"
+)
+
+// TestBackendTransportPoolsConnections guards the fix for the gateway->backend
+// connection churn. Every synchronous client call proxies to the single backend host,
+// so the REST client must widen the idle-connection pool past the default per-host cap
+// of 2 (http.DefaultMaxIdleConnsPerHost) — otherwise almost every request under load
+// opens a fresh TCP connection that then lingers in TIME_WAIT, burning gateway CPU and
+// exhausting ephemeral ports. Reverting to the default transport (`&http.Client{...}`
+// with no Transport) would silently reintroduce that, so assert the pool is widened.
+func TestBackendTransportPoolsConnections(t *testing.T) {
+	c, err := New("http://backend.invalid", "localhost:9090", time.Second)
+	if err != nil {
+		t.Fatalf("New: %v", err)
+	}
+	defer func() { _ = c.Close() }()
+
+	tr, ok := c.http.Transport.(*http.Transport)
+	if !ok {
+		t.Fatalf("REST transport = %T, want a *http.Transport with a widened idle pool", c.http.Transport)
+	}
+	if tr.MaxIdleConnsPerHost <= http.DefaultMaxIdleConnsPerHost {
+		t.Errorf("MaxIdleConnsPerHost = %d, want > default %d (else per-call connection churn)",
+			tr.MaxIdleConnsPerHost, http.DefaultMaxIdleConnsPerHost)
+	}
+}

gateway/internal/botlink/command.go

@@ -36,3 +36,15 @@ func SendToGameChannelCommand(text string) *botlinkv1.Command {
 		}},
 	}
 }
+
+// ChatGateCommand builds a chat-gate command that sets whether the Telegram user
+// identified by externalID may write in the moderated discussion chat. The bot
+// applies it only to a member currently in the chat (guarded on getChatMember).
+func ChatGateCommand(externalID string, allow bool) *botlinkv1.Command {
+	return &botlinkv1.Command{
+		Payload: &botlinkv1.Command_ChatGate{ChatGate: &botlinkv1.ChatGateCommand{
+			ExternalId: externalID,
+			Allow:      allow,
+		}},
+	}
+}

gateway/internal/botlink/hub.go

@@ -31,6 +31,13 @@ var ErrNoBot = errors.New("botlink: no bot connected")
 // (at-most-once under backpressure).
 const outboundBuffer = 64
 
+// EligibilityResolver answers a Telegram identity's moderated-chat write eligibility
+// for the bot's join-time ResolveChatEligibility query: registered reports whether the
+// identity maps to an account, eligible is the final gate the bot acts on (registered
+// and neither admin-suspended nor chat-muted). The gateway backs it with the backend
+// chat-access endpoint.
+type EligibilityResolver func(ctx context.Context, externalID string) (registered, eligible bool, err error)
+
 // Hub registers connected bots and routes send commands to them. A single bot is
 // expected today; the registry already holds a set so adding more later needs no
 // rewrite.
@@ -38,6 +45,7 @@ type Hub struct {
 	botlinkv1.UnimplementedBotLinkServer
 
 	log         *zap.Logger
+	eligibility EligibilityResolver
 
 	mu      sync.Mutex
 	links   map[*link]struct{}
@@ -56,13 +64,16 @@ type link struct {
 	out         chan *botlinkv1.ToBot
 }
 
-// NewHub builds a Hub. A nil meter disables metrics; a nil logger is tolerated.
-func NewHub(log *zap.Logger, meter metric.Meter) *Hub {
+// NewHub builds a Hub. resolve answers the bot's join-time chat-eligibility query
+// (nil rejects it as unavailable). A nil meter disables metrics; a nil logger is
+// tolerated.
+func NewHub(log *zap.Logger, meter metric.Meter, resolve EligibilityResolver) *Hub {
 	if log == nil {
 		log = zap.NewNop()
 	}
 	h := &Hub{
 		log:         log,
+		eligibility: resolve,
 		links:       make(map[*link]struct{}),
 		pending:     make(map[string]chan *botlinkv1.Ack),
 	}
@@ -120,6 +131,22 @@ func (h *Hub) Link(stream grpc.BidiStreamingServer[botlinkv1.FromBot, botlinkv1.
 	}
 }
 
+// ResolveChatEligibility serves the bot's join-time query: whether the Telegram user
+// identified in the request may write in the moderated discussion chat. It delegates
+// to the configured resolver (the backend chat-access endpoint), unlike the streamed
+// Commands it is a plain request/response over the same mTLS channel.
+func (h *Hub) ResolveChatEligibility(ctx context.Context, req *botlinkv1.ChatEligibilityRequest) (*botlinkv1.ChatEligibilityResponse, error) {
+	if h.eligibility == nil {
+		return nil, status.Error(codes.Unavailable, "chat eligibility resolver not configured")
+	}
+	registered, eligible, err := h.eligibility(ctx, req.GetExternalId())
+	if err != nil {
+		h.log.Warn("resolve chat eligibility failed", zap.String("external_id", req.GetExternalId()), zap.Error(err))
+		return nil, status.Error(codes.Internal, "resolve chat eligibility")
+	}
+	return &botlinkv1.ChatEligibilityResponse{Registered: registered, Eligible: eligible}, nil
+}
+
 // register adds a connected bot.
 func (h *Hub) register(l *link) {
 	h.mu.Lock()

gateway/internal/botlink/hub_test.go

@@ -8,7 +8,9 @@ import (
 	"time"
 
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/status"
 	"google.golang.org/grpc/test/bufconn"
 
 	botlinkv1 "scrabble/pkg/proto/botlink/v1"
@@ -23,12 +25,18 @@ type fakeBot struct {
 	received  chan *botlinkv1.Command
 }
 
-// startHub registers a Hub on an in-memory gRPC server and returns the hub plus a
-// dialer for fake bots.
+// startHub registers a Hub (no chat-eligibility resolver) on an in-memory gRPC
+// server and returns the hub plus a dialer for fake bots.
 func startHub(t *testing.T) (*Hub, func(t *testing.T) botlinkv1.BotLinkClient) {
+	return startHubWith(t, nil)
+}
+
+// startHubWith is startHub with an explicit chat-eligibility resolver, for the
+// ResolveChatEligibility tests.
+func startHubWith(t *testing.T, resolve EligibilityResolver) (*Hub, func(t *testing.T) botlinkv1.BotLinkClient) {
 	t.Helper()
 	lis := bufconn.Listen(1 << 20)
-	hub := NewHub(nil, nil)
+	hub := NewHub(nil, nil, resolve)
 	srv := grpc.NewServer()
 	botlinkv1.RegisterBotLinkServer(srv, hub)
 	go func() { _ = srv.Serve(lis) }()
@@ -162,6 +170,62 @@ func TestHubSendAsync(t *testing.T) {
 	}
 }
 
+func TestHubSendChatGate(t *testing.T) {
+	hub, dial := startHub(t)
+	ctx := t.Context()
+	bot := &fakeBot{ack: false}
+	bot.connect(t, ctx, hub, dial(t))
+
+	hub.Send(ChatGateCommand("42", true))
+	select {
+	case cmd := <-bot.received:
+		cg := cmd.GetChatGate()
+		if cg.GetExternalId() != "42" || !cg.GetAllow() {
+			t.Errorf("chat_gate = %+v, want external_id=42 allow=true", cg)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("bot received no command")
+	}
+}
+
+func TestHubResolveChatEligibility(t *testing.T) {
+	var gotExt string
+	_, dial := startHubWith(t, func(_ context.Context, ext string) (bool, bool, error) {
+		gotExt = ext
+		return true, ext == "good", nil
+	})
+	client := dial(t)
+	ctx := t.Context()
+
+	resp, err := client.ResolveChatEligibility(ctx, &botlinkv1.ChatEligibilityRequest{ExternalId: "good"})
+	if err != nil {
+		t.Fatalf("ResolveChatEligibility: %v", err)
+	}
+	if gotExt != "good" {
+		t.Errorf("resolver external_id = %q, want good", gotExt)
+	}
+	if !resp.GetRegistered() || !resp.GetEligible() {
+		t.Errorf("resp = %+v, want registered+eligible", resp)
+	}
+
+	resp, err = client.ResolveChatEligibility(ctx, &botlinkv1.ChatEligibilityRequest{ExternalId: "muted"})
+	if err != nil {
+		t.Fatalf("ResolveChatEligibility(muted): %v", err)
+	}
+	if !resp.GetRegistered() || resp.GetEligible() {
+		t.Errorf("resp = %+v, want registered but not eligible", resp)
+	}
+}
+
+func TestHubResolveChatEligibilityUnconfigured(t *testing.T) {
+	_, dial := startHub(t) // nil resolver
+	client := dial(t)
+	_, err := client.ResolveChatEligibility(t.Context(), &botlinkv1.ChatEligibilityRequest{ExternalId: "x"})
+	if status.Code(err) != codes.Unavailable {
+		t.Fatalf("err = %v, want Unavailable", err)
+	}
+}
+
 func TestRelayServerNoBot(t *testing.T) {
 	hub, _ := startHub(t)
 	relay := NewRelayServer(hub, 200*time.Millisecond)

gateway/internal/botlink/mtls_test.go

@@ -94,7 +94,7 @@ func startMTLSHub(t *testing.T) (hub *Hub, addr, caFile, cliCert, cliKey string)
 	if err != nil {
 		t.Fatalf("listen: %v", err)
 	}
-	hub = NewHub(nil, nil)
+	hub = NewHub(nil, nil, nil)
 	srv := grpc.NewServer(grpc.Creds(credentials.NewTLS(tlsCfg)))
 	botlinkv1.RegisterBotLinkServer(srv, hub)
 	go func() { _ = srv.Serve(lis) }()

loadtest/README.md

@@ -15,10 +15,12 @@ and prints a trip-report summary. It stays in the repo for repeats.
 2. **Drive** (edge protocol over h2c): assembles real 2–4 player games via the
    invitation flow (`invitation.create` → `invitation.accept`, no robots), then runs
    each player's turn loop — poll `game.state`, replay `game.history`, generate a legal
-   **mid-ranked** move with the embedded `scrabble-solver`, and `game.submit_play`
-   (or pass/exchange). A fraction of turns exercise nudge / chat / check-word / draft /
-   profile-update / stats. Each player also holds a live `Subscribe` stream. The
-   moderate ramp is **50 → 200 → 500** concurrent players, ~12 min per step.
+   **mid-ranked** move with the embedded `scrabble-solver`, **compose it tile by tile with
+   the debounced `game.evaluate` preview a real client fires** (the hottest gameplay call),
+   persist a `draft.save`, and `game.submit_play` (or pass/exchange). A fraction of turns
+   exercise nudge / chat / check-word / draft / profile-update / stats. Each player also
+   holds a live `Subscribe` stream. The moderate ramp is **50 → 200 → 500** concurrent
+   players, ~12 min per step. `--eval=false` drops the evaluate model for an A/B baseline.
 3. **Hammer**: drives `games.list` from one account far above the per-user rate limit
    to verify the limiter holds (`rate_limited` results) and measure its cost.
 4. **Report**: per-operation latency percentiles, throughput, result-code breakdown,
@@ -72,6 +74,8 @@ Key `run` flags (env in parentheses):
 | `--games-per-player` | `0` (random 3–5) | target concurrent games per player |
 | `--tick` | `800ms` | per-player op cadence (keeps a player under the per-user limit) |
 | `--secondary-prob` | `0.08` | chance per tick of a non-move op |
+| `--eval` | `true` | model the per-tile `game.evaluate` preview (the gameplay hot path); `false` reproduces the pre-evaluate harness |
+| `--eval-recon` | `1` | extra full-composition evaluate re-previews per play (reconsideration), beyond one per placed tile |
 | `--hammer-workers` / `--hammer-dur` | `20` / `15s` | gateway-hammer (0 workers disables) |
 | `--reset` / `--cleanup` | `false` | delete harness rows before / after the run |
 
@@ -93,11 +97,11 @@ runs unconditionally. Use an **absolute** path (here via `$PWD`): `go test ./loa
 runs each package from its own directory, so a relative `BACKEND_DICT_DIR` would not
 resolve.
 
-## Trip reports
+## Trip report
 
-The two stress passes are written up in the repo: the early pass in
-[`REPORT-R2.md`](REPORT-R2.md) and the final, tuned pass in
-[`REPORT-R7.md`](REPORT-R7.md).
+The stress findings — the final run, the `game.evaluate` hot-path model, the
+gateway→backend connection-pool fix, and the revised sizing — are written up in
+[`REPORT.md`](REPORT.md).
 
 ## Caveat
 

loadtest/REPORT-R2.md

@@ -1,162 +0,0 @@
-# R2 — early stress-run trip report
-
-The early stress pass for `PRERELEASE.md` R2. It exercises the system through the
-**edge protocol** with the `scrabble/loadtest` harness, to surface logic/concurrency
-bugs and capture a resource baseline that feeds R3 (edge hardening), R6 (refactor) and
-R7 (final tuning). Pass bar: **diagnostic** — the run "passes" by completing without the
-harness crashing; findings are recorded below, not gated.
-
-## Method
-
-- **Driver:** the `scrabble/loadtest` module, run as a one-shot container on the
-  `scrabble-internal` docker network (reaching `postgres:5432` and `gateway:8081`
-  directly, bypassing the host→gateway hairpin).
-- **Seed:** 10 000 durable + 1 000 guest accounts with pre-created sessions written
-  directly to Postgres (token hash matches `backend/internal/session`), so the driver
-  authenticates without the per-IP-limited auth ops.
-- **Games:** assembled through the real **invitation** flow (`invitation.create` →
-  `invitation.accept`), 2–4 players each, no robots; variants spread over
-  scrabble_en / scrabble_ru / erudit_ru.
-- **Play:** each virtual player holds a live `Subscribe` stream and, per tick, polls
-  `game.state`, replays `game.history` and submits a **mid-ranked** legal move generated
-  locally by the embedded `scrabble-solver` (the edge carries no board), or
-  passes/exchanges; a fraction exercise nudge / chat / check-word / draft / profile /
-  stats. A separate **gateway-hammer** floods `games.list` from one account.
-- **Scale:** moderate ramp **50 → 200 → 500** concurrent players, 10 min/step (the
-  agreed moderate profile; harness and contour share this host's CPU).
-- **Resource capture:** `docker stats` (docker API) sampled every 28 s for per-container
-  CPU/memory; Prometheus for edge latency/throughput, `postgres_exporter` internals and
-  per-service Go runtime metrics.
-
-## Run configuration
-
-```
-loadtest run --durable 10000 --guest 1000 --steps 50,200,500 --step-dur 10m \
-             --tick 800ms --hammer-workers 20 --hammer-dur 15s --cleanup
-```
-
-Date: 2026-06-09. Contour: the R1-baseline schema, freshly deployed with the R2
-exporters. Seeded population removed by `--cleanup` afterwards.
-
-## Findings
-
-### Validated (fixed within R2)
-- **Harness draft payload.** `draft.save` first returned `bad_request`: the backend
-  draft DTO's `rack_order` is a string (the harness sent `[]`). Fixed → `ok`.
-- **Harness profile marker.** `profile.update` first returned `invalid_profile`: the
-  editable-display-name validator (`backend/internal/account/profile.go`) forbids digits
-  and colons, but the seed marker was `lt:…`. Switched the marker to a distinctive
-  letters-only string → `ok`. Cleanup still matches it.
-
-### By-design behaviour (correctly exercised, not bugs)
-- **`chat_not_your_turn`** — chat is gated to the sender's turn
-  (`backend/internal/social/chat.go`); off-turn posts are correctly rejected.
-- **`nudge_own_turn`** — you nudge the player whose turn it is, so a nudge on your own
-  turn is correctly rejected. The harness nudges/chats at random ticks, so a share of
-  these codes is expected.
-
-### Observability gap (key R7 input)
-- **cAdvisor yields only the root cgroup on the contour host.** Its docker factory
-  registers, but per-container init fails — `failed to identify the read-write layer ID
-  … /rootfs/var/lib/docker/image/overlayfs/…: no such file or directory` — because this
-  host's `/var/lib/docker` is a **separate XFS mount** not visible under cAdvisor's
-  `/rootfs` bind (the existing galaxy deployment on the same host has the same
-  limitation). So the **Scrabble — Resources** dashboard's per-container panels are empty
-  here, and per-container CPU/RSS for this run was captured via `docker stats` instead.
-  Postgres internals (`postgres_exporter`) and per-service Go runtime metrics
-  (`go_*` by `service_name`) work. **Recommendation for R7:** adopt the otelcol
-  **`docker_stats`** receiver (already the contrib image) — it reads per-container stats
-  via the docker API with no cgroup dependency — and/or run the final pass on hardware
-  where cAdvisor resolves containers. (Decision to confirm with the owner.)
-
-### Run results
-
-The ramp ran clean to 500 players with no harness crash, no deadlock and
-`stream errors: 0`; cleanup removed all 11 000 seeded accounts (and their ~941 games).
-
-- **Ramp:** step 1 = 50 players / 90 games, step 2 = 200 / 282, step 3 = 500 / 569.
-- **Volume (30 min):** 1.20 M total edge calls, 659 req/s average. Real gameplay at
-  scale: **48 870 committed plays**, 52 772 `your_turn` + 159 631 `opponent_moved`
-  events, **2 798 games finished**.
-- **Latency under load (peak, step 3):** `game.state` p50 ≈ 100 ms, p90/p99 in the
-  200–500 ms buckets, max 849 ms; `game.submit_play` similar (p99 ≤ 500 ms, max 490 ms).
-  Lobby ops stayed fast (invitation/games.list p99 ≤ 10 ms).
-- **Rate limiter holds.** The gateway-hammer sent 522 667 `games.list` from one account;
-  **522 486 (99.97 %) were `rate_limited`**, only 135 `ok` (the burst). Rejections are
-  cheap — p99 = 2 ms — and the gateway sustained ~16 k req/s of rejections during the
-  flood. The per-user limiter behaves as designed (R3 input: the cost is negligible).
-
-**Top finding — `transport_error` under saturation.** At 500 players ~14 % of
-`game.state` calls (72 429 / 519 067) and a few % of the other ops returned a Connect
-`transport_error` (not a domain code). It correlates with the CPU saturation below: the
-backend/gateway are pinned near one core each while the host also runs the 86 %-core
-harness, so the edge sheds load (resets/timeouts) at the knee. It is **amplified by a
-harness artifact** — all 500 virtual players multiplex over a *single* shared
-`http2.Transport`, so 500 persistent `Subscribe` streams plus Execute calls press on one
-HTTP/2 connection's concurrent-stream limit; real clients each use their own connection.
-**Actions:** R7 harness — give each player (or a pool) its own transport, and run on
-hardware not shared with the contour; R3 — confirm the gateway's h2c
-`MaxConcurrentStreams` and edge timeouts are sized for many persistent streams.
-
-**Minor findings:**
-- `unauthenticated` on a tiny share (188 / 519 067 `game.state`, ~0.04 %) — transient
-  session-resolve failures under load; worth a glance in R3 but not material.
-- one `internal` on `game.pass` (1 / 4 788).
-- `game_finished` dominates `chat.nudge`/`chat.post` (≈ 3 900 each): the harness keeps
-  secondary ops on games that already ended. Harness refinement — drop finished games
-  from the rotation (R7).
-- `nudge_own_turn` / `chat_not_your_turn` / `nudge_too_soon` are the expected turn/rate
-  gates, correctly exercised.
-
-## Resource baseline
-
-Per-container peak during step 3 (500 players), from `docker stats`:
-
-| container | peak CPU | memory |
-|-----------|---------:|-------:|
-| scrabble-backend | **99 %** (~1 core) | 91 MiB |
-| scrabble-gateway | **93 %** | 76 MiB |
-| scrabble-postgres | **90 %** | 69 MiB |
-| scrabble-loadtest (harness) | **86 %** | 42 MiB |
-| scrabble-otelcol | 10 % | 110 MiB |
-| scrabble-tempo | 9 % | 446 MiB |
-| prometheus / postgres-exporter | ~0 % | 46 / 16 MiB |
-
-- **The contour is CPU-bound at 500 concurrent players:** backend, gateway and Postgres
-  each saturate ~1 core (single-instance MVP config), so the system draws ~3 cores at
-  this scale; memory is modest (≤ 100 MiB per Go service). This is the sizing input for
-  R7 (pool sizes, GOMAXPROCS, container limits) and the prod cutover.
-- **Caveat:** the harness itself peaked at **86 % of a core** on the *same host*, so the
-  step-3 latency and `transport_error` figures are pessimistic — the contour competed
-  with the generator for CPU. A clean ceiling needs separate hardware (R7).
-- **Postgres:** peak 28 backend connections, ~5 581 commits/s at the peak, **100 % cache
-  hit ratio** (no disk reads) — the DB was comfortable; CPU, not I/O, is its limit here.
-- **Goroutines:** backend 638, gateway **1 698** (it holds the 500 `Subscribe` streams +
-  per-request goroutines), telegram 49 — all stable, no leak across the ramp.
-
-## Recommendations feeding later phases
-- **R3 (edge hardening):** the per-user limiter holds (99.97 % rejected, p99 2 ms) — add
-  the per-IP body-size cap on top. Investigate the **~14 % `transport_error` on
-  `game.state` at 500 players**: confirm the gateway h2c `MaxConcurrentStreams` and edge
-  read/write timeouts are sized for many persistent `Subscribe` streams, and glance at the
-  ~0.04 % transient `unauthenticated` resolves under load.
-- **R6 (refactor):** no logic bug forced a code change beyond the two harness-payload
-  fixes; the run surfaced no deadlock or goroutine leak across the ramp.
-- **R7 (final tuning + stress):** (1) fix the per-container observability gap — adopt the
-  otelcol `docker_stats` receiver so Grafana shows per-container CPU/RSS on the contour;
-  (2) refine the harness — per-player/pooled transports and dropping finished games from
-  the rotation — and run on hardware **not** shared with the contour; (3) size pools /
-  GOMAXPROCS / container limits from the CPU-bound peak (~1 core each for backend, gateway,
-  Postgres at 500 players).
-
-## Re-running
-
-See [`README.md`](README.md). Briefly, from the repo root:
-
-```sh
-docker build -f loadtest/Dockerfile -t scrabble-loadtest .
-docker run --rm --name scrabble-loadtest --network scrabble-internal \
-  -e POSTGRES_PASSWORD=… scrabble-loadtest run    # add --reset on a re-run
-```
-
-The harness stays in the repo for the R7 repeat.

loadtest/REPORT-R7.md

@@ -1,212 +0,0 @@
-# R7 — final stress-run trip report
-
-The final pre-release stress pass for [`PRERELEASE.md`](../PRERELEASE.md) R7. It re-runs
-the R2 harness (`scrabble/loadtest`) against the **final, refactored system** on a
-freshly redeployed contour, to confirm the system holds at scale and to settle the
-resource sizing (container limits, `GOMAXPROCS`, pools, rate limits, log levels) before
-the Stage 18 prod cutover. Pass bar: **diagnostic + a tuning decision** — the run
-"passes" by completing cleanly; the per-container resource profile drives the tuning
-recorded below. Companion to the early pass, [`REPORT-R2.md`](REPORT-R2.md).
-
-## What changed since the R2 pass
-
-- **Harness — per-player transports.** Each virtual player now owns its `edge.Client`
-  (its own `http2.Transport` / h2c connection carrying both its `Subscribe` stream and
-  its `Execute` calls), instead of all players multiplexing over one shared transport.
-  R2 traced the ~14 % `transport_error` on `game.state` at 500 players to that single
-  shared connection's stream limit; per-player connections mirror real clients and
-  remove the artifact, so this pass measures the system, not the harness.
-- **Harness — drop finished games.** `playTurn` reports a finished game and the player
-  drops it from its rotation, so secondary ops stop hitting `game_finished` on ended
-  games (the other R2 harness finding).
-- **Observability — otelcol `docker_stats`.** cAdvisor (which resolves only the root
-  cgroup on this host — separate-XFS `/var/lib/docker`) is replaced by the otelcol
-  `docker_stats` receiver, reading per-container CPU/memory/network from the Docker API.
-  Per-container panels now populate on the contour host. (`api_version` pinned to 1.44;
-  the daemon's minimum is 1.40.)
-- **Contour — container limits + `GOMAXPROCS`.** `deploy.resources.limits` now bound
-  every service; the Go services pin `GOMAXPROCS` to their CPU limit so the runtime
-  matches the cgroup quota. Starting values were generous over the R2 peak; this pass
-  validates them and settles the agreed sizing (below).
-
-## Method
-
-Unchanged from R2 except for the per-player transports and the dropped-finished-games
-refinement above:
-
-- **Driver:** the `scrabble/loadtest` module, run as a one-shot container on the
-  `scrabble-internal` docker network (reaching `postgres:5432` / `gateway:8081`
-  directly), capped at `--cpus 3` so the contour keeps the host's spare cores.
-- **Seed:** 10 000 durable + 1 000 guest accounts with pre-created sessions written
-  straight to Postgres (token hash matches `backend/internal/session`).
-- **Games:** assembled through the real **invitation** flow, 2–4 players each, no
-  robots; variants over scrabble_en / scrabble_ru / erudit_ru.
-- **Play:** each player holds a live `Subscribe` stream and, per tick, polls
-  `game.state`, replays `game.history` and submits a **mid-ranked** legal move generated
-  locally by the embedded `scrabble-solver`, or passes / exchanges; a fraction exercise
-  nudge / chat / check-word / draft / profile / stats. A separate **gateway-hammer**
-  floods `games.list` from one account.
-- **Scale:** the same moderate ramp **50 → 200 → 500** concurrent players, 10 min/step.
-- **Resource capture:** `docker stats` (docker API) sampled every ~20 s for per-container
-  CPU/memory; the otelcol **`docker_stats`** receiver → Prometheus → the Grafana
-  **Scrabble — Resources** dashboard for the same per-container series; `postgres_exporter`
-  internals and per-service Go runtime metrics.
-
-## Run configuration
-
-```
-docker run --rm --cpus=3 --name scrabble-loadtest --network scrabble-internal \
-  -e POSTGRES_PASSWORD=… scrabble-loadtest \
-  run --durable 10000 --guest 1000 --steps 50,200,500 --step-dur 10m \
-      --tick 800ms --hammer-workers 20 --hammer-dur 15s --reset --cleanup
-```
-
-Date: 2026-06-10. Contour: the R1-baseline schema, freshly redeployed with the R7
-container limits / `GOMAXPROCS` (backend/gateway/postgres capped at 2 cores + 512 MiB,
-`GOMAXPROCS=2`) and the `docker_stats` observability. Seeded population removed by
-`--cleanup` afterwards.
-
-## Findings
-
-The ramp ran clean to 500 players — no harness crash, no deadlock, `stream errors: 0` —
-and cleanup removed all 11 000 seeded accounts.
-
-- **Volume (1827 s):** 821 680 edge calls (449.7 req/s incl. the hammer). Real gameplay
-  at scale: **50 916 committed plays**, 4 817 passes, 2 931 games finished; 165 755
-  `opponent_moved` + 54 864 `your_turn` events.
-- **The per-player transport fix worked.** `game.state` returned `transport_error` on
-  **3 173 / 127 403 = 2.49 %** of calls — down from R2's ~14 % on the same step. Other
-  ops were lower still (`game.history` 0.43 %, `game.submit_play` 0.28 %). The residual
-  is the gateway bursting into its 2-core cap (see the profile below), not the harness.
-- **Dropping finished games worked.** `game_finished` on `chat.nudge` / `chat.post` fell
-  to **35 / 36** (R2: ≈ 3 900 each) — secondary ops no longer hammer ended games.
-- **The limiter holds.** The gateway-hammer sent 565 152 `games.list`; **564 979
-  (99.97 %) were `rate_limited`** (154 ok burst, 19 deadline), p99 = 2 ms, ~309 req/s of
-  rejections sustained — unchanged from R2.
-- **Latency (peak):** `game.state` p50 ≈ 100 ms, p99 in the 2000 ms bucket (max 2549 ms);
-  `game.submit_play` p50 100 / p99 1000 ms bucket. Lobby ops stayed fast
-  (invitation / games.list p99 ≤ 10 ms). The p99 tail correlates with the gateway
-  burst-throttling, not the backend (which stayed at ~0.85 core).
-
-## Resource profile
-
-Per-container peak during step 3 (500 players), with the R7 starting limits in force
-(backend/gateway/postgres capped at 2 cores / 512 MiB). Two CPU columns: `docker stats`
-samples a ~1 s window (catches bursts); the otelcol `docker_stats` receiver averages over
-its 30 s collection interval (smooths them) — they agree within sampling error, which
-validates the new observability path.
-
-| container | CPU burst (1 s) | CPU sustained (30 s) | CPU cap | mem peak | mem cap |
-|-----------|----------------:|---------------------:|--------:|---------:|--------:|
-| scrabble-gateway | **217 %** (at cap) | ~145 % | 200 % | 167 MiB | 512 MiB |
-| scrabble-postgres | 138 % | ~153 % | 200 % | 117 MiB | 512 MiB |
-| scrabble-backend | 85 % | ~89 % | 200 % | 116 MiB | 512 MiB |
-| scrabble-tempo | 33 % | — | (none) | **1024 MiB** (at cap) | 1024 MiB |
-| scrabble-otelcol | 11 % | — | (none) | 131 MiB | 512 MiB |
-| scrabble-loadtest (harness) | 157 % | — | 300 % | 369 MiB | — |
-
-- **The gateway is the binding constraint.** With one h2c connection per player it draws
-  ~1.45 cores sustained and **bursts to its 2-core cap** at 500 players, throttling
-  briefly — the source of the 2.49 % `transport_error`. R2 saw only ~0.93 core because
-  all 500 players shared one connection; the +~0.5 core is the realistic per-connection
-  overhead (500 separate HTTP/2 connections). This is a sizing fact, not a regression.
-- **backend is over-provisioned** (~0.85 core vs a 2-core cap); **postgres** (~1.4 cores)
-  has headroom; both stayed ≤ 120 MiB.
-- **tempo reached its 1 GiB memory cap** (R2: 446 MiB) — an OOM risk under sustained
-  tracing.
-- **Postgres backends peaked at 28**, with the backend pool at its `MaxOpenConns=25` cap.
-  Cache hit stayed ~100 % (no disk reads); CPU, not I/O, is the limit.
-- **docker log volume (30 min):** backend 14.2 MiB, gateway 4.6 MiB, postgres 0.04 MiB —
-  the backend's per-request latency line at info dominates, and json-file logs had no
-  rotation.
-
-## Tuning applied
-
-Agreed from the profile (all in `deploy/docker-compose.yml`; no code change — the pool
-is already env-driven):
-
-| knob | from | to | why |
-|------|------|----|-----|
-| gateway CPU + `GOMAXPROCS` | 2 cores / 2 | **3 cores / 3** | it bursts into the 2-core cap at 500 players (the 2.49 % `transport_error`); 3 absorbs the bursts |
-| tempo memory | 1 GiB | **2 GiB** | it reached the 1 GiB cap (OOM risk) |
-| backend `MAX_OPEN_CONNS` | 25 | **40** | the pool sat at its 25-conn cap at peak; headroom trims the p99 tail |
-| docker logs | unbounded | **json-file 10m × 3** | bound the ~14 MiB / 30 min backend log; level stays `info` |
-
-Left as-is: backend / postgres at 2 cores / 512 MiB (peak ~0.85 / ~1.4 cores — headroom
-is cheap on the shared host); the per-user rate limiter and `h2cMaxConcurrentStreams=250`
-(per-connection now, ~1 stream each — ample) and cache TTLs (no pressure observed).
-
-### Validation re-run
-
-Re-running the **same gradual ramp** (50 → 200 → 500) on the tuned contour confirms the
-fix:
-
-- **`game.state` `transport_error` fell to 0.72 %** (853 / 119 051), down from 2.49 % at
-  2 cores. The latency tail also improved — p99 in the 1000 ms bucket, max 1220 ms (was
-  the 2000 ms bucket, max 2549 ms).
-- The **gateway peaked at ~2 cores** (≈196 % on the 30 s gauge) — now comfortably **under
-  the 3-core cap**, so it no longer throttles. backend ~1 core, postgres ~1.3 cores.
-- **tempo peaked at ~1.27 GiB** — under the new 2 GiB cap (it would have OOM-ed at 1 GiB).
-- Drop-finished still holds (`game_finished` on chat 41/42); the limiter still rejects
-  99.97 % of the hammer at p99 2 ms; `stream errors: 0`.
-
-A separate **burst stress** (a single 100 → 500 jump — 400 players connecting at once)
-**pegged the gateway at 3 cores** (≈296 % sustained) and pushed `game.state`
-`transport_error` to 9.27 %. The gateway is **connection-CPU-bound and bursty**: average
-load is ~1 core, but a mass-simultaneous connection storm saturates whatever single-node
-cap it is given. Real arrivals are gradual (the canonical run), where 3 cores has
-headroom; the lever for a true arrival spike is **horizontal scaling**, not more cores per
-node — carried into the prod recommendation below.
-
-## Prod-sizing recommendation (Stage 18)
-
-The contour is **CPU-bound and gateway-led** at 500 concurrent players. Carry these to the
-prod contour env (the same compose, `PROD_*` values):
-
-- **gateway: ≥ 3 cores** per ~500 concurrent players, `GOMAXPROCS` pinned to the limit —
-  it scales with the **connection count**, not just the request rate; beyond one node's
-  worth, scale the gateway **horizontally** rather than vertically.
-- **backend: ~1–2 cores**, pool 40 — comfortable; the work is light per request.
-- **postgres: ~2 cores / ≥ 512 MiB** — ~1.4 cores at 500 players, 100 % cache hit.
-- **tempo: ≥ 2 GiB**; the Go services run under ~170 MiB (256 MiB would suffice, 512 is
-  safe); pin `GOMAXPROCS` to each CPU limit; keep json-file rotation.
-- Memory is not the constraint anywhere; CPU is.
-
-### VPS / VDS sizing (single-host contour)
-
-The whole contour (the app + the observability stack) runs on one host via
-`docker-compose`. The tiers below are grounded in the R7 profile (**≈5.5 cores / ≈2.5 GiB
-RAM peak at 500 concurrent players**; ≈0.5 GiB idle) and the **measured** on-disk
-footprint: prod images ≈2.4 GB; the Tempo volume **3.1 GB at 72 h** retention; Prometheus
-≈1–2 GB at 15 d; the game DB 23 MiB and growing with history. CPU and disk grow; RAM has
-the most slack.
-
-| tier | CPU | RAM | disk | handles |
-|------|-----|-----|------|---------|
-| **Minimum** | 2 cores | 2 GiB | 20 GiB | ~up to ~150 concurrent; lower the compose limits (gateway 1.5 / backend·postgres 1 / tempo 1 GiB) to fit the box |
-| **Average** (reasonable load) | 4 cores | 4 GiB | 40 GiB | ~300–400 concurrent comfortably; the tested 500 with occasional gateway burst-throttling |
-| **Maximum** (worry-free) | 8 cores | 8 GiB | 80 GiB | 500+ concurrent with full gateway burst headroom (its 3-core cap) + room to grow; the compose limits fit as-is |
-
-- The per-service limits in `docker-compose.yml` are tuned for the **Average/Maximum**
-  target (the gateway alone caps at 3 cores). On the **Minimum** tier, scale them down to
-  match the host or the caps over-subscribe it.
-- **Disk is dominated by observability retention + DB growth.** Tempo (72 h traces) and
-  Prometheus (15 d metrics) are the main levers — shorten the windows (or move Tempo to
-  object storage) to cut disk; Postgres grows with game history, so budget for months of
-  it; container logs are already capped (json-file 10m × 3 ≈ 30 MiB each).
-- **RAM** rarely binds: the contour peaks ≈2.5 GiB at 500 players and the sum of all
-  configured limits is ≈5.6 GiB, so 8 GiB never strains.
-- Beyond one host's worth of players, scale the **gateway horizontally** (it is
-  connection-CPU-bound) rather than ordering an ever-bigger box.
-
-## Re-running
-
-See [`README.md`](README.md). Briefly, from the repo root:
-
-```sh
-docker build -f loadtest/Dockerfile -t scrabble-loadtest .
-docker run --rm --cpus=3 --name scrabble-loadtest --network scrabble-internal \
-  -e POSTGRES_PASSWORD=… scrabble-loadtest run --reset --cleanup
-```
-
-The harness stays in the repo for future repeats.

loadtest/REPORT.md

@@ -0,0 +1,194 @@
+# loadtest — stress trip report
+
+The pre-release stress write-up for [`PRERELEASE.md`](../PRERELEASE.md). It drives the
+`scrabble/loadtest` harness against a freshly redeployed test contour to confirm the
+system holds at scale and to settle resource sizing before the prod cutover. The harness
+stays in the repo for repeats; see [`README.md`](README.md) for how to run it.
+
+This report supersedes the earlier per-phase notes. The harness has been through three
+passes: an early diagnostic, a tuning pass that sized container limits / `GOMAXPROCS`, and
+this final pass — which **added the per-tile `game.evaluate` preview to the model** (the
+hottest real gameplay call, previously unmodelled) and, with it, surfaced and fixed the
+**gateway→backend connection-pool bottleneck** described below. The numbers here are from
+that final pass.
+
+## What it models
+
+The harness seeds a large account population with pre-created sessions directly in
+Postgres, then drives virtual players through the **gateway edge protocol** (h2c) in real
+games assembled via the invitation flow. Each player owns its own `edge.Client` (its own
+h2c connection, like a real client), holds a live `Subscribe` stream, and per tick polls
+`game.state`, replays `game.history`, generates a legal **mid-ranked** move with the
+embedded `scrabble-solver`, and submits it (or passes/exchanges). A fraction of ticks
+exercise nudge / chat / check-word / draft / profile / stats. A separate **gateway-hammer**
+floods `games.list` to verify the rate limiter.
+
+### The evaluate hot path (this pass)
+
+A real client previews every tentative play as the user arranges tiles: the UI fires a
+debounced `game.evaluate` (legality + score) on each placement change while it is the
+player's turn. Over a single composed word that is **several evaluate calls per turn** —
+far more than the one `submit_play` — so `game.evaluate` is the single hottest gameplay
+request at scale. The earlier passes did not model it at all (they submitted directly),
+which understated the real load.
+
+This pass models it: when a player composes a play of *K* newly-placed tiles, it fires one
+`evaluate` per landed tile (a growing prefix of the tiles), plus a small number of
+full-composition re-previews for reconsideration, spaced by a human-paced gap (the client's
+250 ms debounce), then one `draft.save`, then `submit_play`. `--eval=false` reproduces the
+pre-evaluate harness for an A/B baseline; `--eval-recon` tunes the reconsideration count.
+
+`game.check_word` is a *different*, manual "look this word up" panel (throttled, on demand)
+— not the per-tile call — and is exercised separately as a secondary op.
+
+## Final run (eval-on, after the connection-pool fix)
+
+Contour: backend / postgres capped at 2 cores / 512 MiB (`GOMAXPROCS=2`), gateway at
+3 cores / 512 MiB (`GOMAXPROCS=3`), per the tuned `deploy/docker-compose.yml`. Gradual ramp
+**50 → 200 → 500** concurrent players, 4 min/step, `--tick 800ms`, gateway-hammer on. The
+harness ran as a one-shot container on `scrabble-internal`, capped at `--cpus 3`. The DB was
+wiped before the run (`DROP SCHEMA backend CASCADE`); the seeded population was removed by
+`--cleanup` afterwards.
+
+Per-operation results at the 500-player peak (740 s, gameplay rows; the hammer row is the
+limiter probe):
+
+| operation | count | req/s | p50 | p99 | max | notes |
+|-----------|------:|------:|----:|----:|----:|-------|
+| game.evaluate | 85 721 | 115.9 | 1 ms | 200 ms | 193 ms | **the hot path** — all ok |
+| game.state | 115 926 | 156.7 | 100 ms | 200 ms | 260 ms | transport_error 86 (0.07 %) |
+| game.history | 22 258 | 30.1 | 5 ms | 100 ms | 195 ms | all ok |
+| draft.save | 23 031 | 31.1 | 2 ms | 200 ms | 194 ms | all ok |
+| game.submit_play | 21 704 | 29.3 | 1 ms | 200 ms | 274 ms | ok 3 902; not_your_turn / illegal_play are concurrent-play races (see caveat) |
+| hammer:games.list | 522 756 | 706.7 | 1 ms | 2 ms | 53 ms | **99.97 % rate_limited** — limiter holds |
+
+- **Volume:** 802 200 total edge calls (1 084 req/s incl. the hammer; ~377 req/s of real
+  gameplay). `stream errors: 0`. Live events: 11 199 `opponent_moved`, 4 153 `your_turn`.
+- **`game.evaluate` is the dominant gameplay write-path call** at ~116 req/s — second only
+  to the `game.state` poll — and it is cheap: p50 1 ms, effectively zero errors. The backend
+  serves it straight from the in-memory live-game cache; on a warm hit it skips the database
+  entirely (see *Postgres read path* below, which halved its p99 to 100 ms).
+- **Latency stayed healthy** under the heavier evaluate load: every gameplay op p99 ≤ 200 ms.
+- **The limiter holds** unchanged: 99.97 % of the hammer rejected at p99 2 ms.
+
+### Peak CPU (500 players)
+
+| container | CPU peak | cap |
+|-----------|---------:|----:|
+| scrabble-postgres | **165 %** (~1.65 cores) | 200 % |
+| scrabble-backend | 77 % (~0.77 core) | 200 % |
+| scrabble-gateway | **26 %** (~0.26 core) | 300 % |
+| scrabble-loadtest (harness) | 42 % | 300 % |
+
+Memory stayed modest everywhere (Go services ≤ ~90 MiB). **Postgres is now the busiest
+service** — it has headroom (1.65 of 2 cores) but is the scaling axis. The gateway, after
+the fix below, is near-idle.
+
+## The headline finding: gateway→backend connection churn
+
+The gateway proxies every synchronous client call to the single backend host over REST.
+Its backend HTTP client used the default transport, whose **`MaxIdleConnsPerHost` is 2**
+(`http.DefaultMaxIdleConnsPerHost`). So the gateway kept only **2** keep-alive connections
+to the backend and opened — then closed — a fresh TCP connection for almost every other
+call. Measured at the gateway's network namespace:
+
+| | gateway→backend sockets |
+|---|---|
+| before (eval-on, 500 players) | **TIME_WAIT ≈ 26 500**, ESTABLISHED 2 |
+| after (eval-on, 500 players) | TIME_WAIT ≈ 0 (steady state), **ESTABLISHED ≈ 225 (reused)** |
+
+26 500 TIME_WAIT sockets is the connection **churn**: ~440 new connections per second,
+each a full TCP handshake + teardown, the socket then lingering 60 s. That count sits right
+under the ~28 000 ephemeral-port ceiling — the latent cliff that produced the residual
+`transport_error` the earlier passes chased on the *client* side (h2c streams) but never
+eliminated, because the real cause was here, on the *backend* side.
+
+The fix is one custom `http.Transport` with a wide idle pool
+(`gateway/internal/backendclient/client.go`, `backendMaxIdleConns`). Before / after, same
+eval-on workload at 500 players:
+
+| metric | before fix | after fix |
+|--------|-----------:|----------:|
+| gateway→backend TIME_WAIT | ~26 500 | **~0** |
+| gateway CPU peak | **175 %** (~1.75 cores) | **26 %** (~0.26 core) |
+| game.state p99 | 500 ms | 200 ms |
+
+**The churn was burning ~1.5 gateway cores of pure connection setup/teardown.** Removing it
+cut peak gateway CPU ~7× and erased the port-exhaustion cliff. The backend and postgres CPU
+are unchanged — they do the real work; only the gateway's wasted overhead disappeared. The
+pool settles at ~225 live connections at 500 players; the constant is set to 512 for ~2×
+headroom.
+
+## Sizing — why the old "≈150 concurrent / 2-core" figure was a bug, not a floor
+
+The earlier tuning pass concluded the gateway was the binding constraint — "size it for
+≥ 3 cores per 500 players, scale it horizontally" — and the single-host "minimum" tier
+topped out near ~150 concurrent. **That was sizing around the connection-churn bug.** The
+gateway drew ~1.75–3 cores not from proxying work but from churning backend connections;
+the backend behind it sat near-idle the whole time.
+
+With the churn fixed, at **500 concurrent players** the app draws roughly:
+
+- **gateway ≈ 0.26 core** (was ~3) — no longer the constraint,
+- **backend ≈ 0.77 core**,
+- **postgres ≈ 1.65 cores** — now the busiest, with headroom,
+
+≈ **2.7 app cores total** (down from the ~5.5-core contour peak the tuning pass recorded,
+*and* under a heavier, more realistic workload that now includes `game.evaluate`). Postgres,
+not the gateway, is the scaling axis.
+
+Revised single-host guidance (app + co-resident observability stack on one box):
+
+| tier | CPU | RAM | handles |
+|------|-----|-----|---------|
+| **Minimum** | 2 cores | 2 GiB | comfortably the low hundreds of concurrent — the gateway no longer eats cores; postgres + the observability stack set the limit |
+| **Average** | 4 cores | 4 GiB | 500 concurrent with headroom |
+| **Maximum** | 8 cores | 8 GiB | 500+ with full burst headroom and room to grow |
+
+The gateway's compose limit can drop well below its old 3 cores; it is now connection-pool
+bound, not connection-CPU bound. Memory was never the constraint. Disk is still dominated
+by observability retention (Tempo, Prometheus) + DB growth — unchanged from before.
+
+## Postgres read path (warm-cache optimization)
+
+Following this pass, `game.evaluate` no longer reads the database on the hot path. An
+active game is already resident in the in-memory live-game cache (mutated in place across
+moves, evicted only on finish), so the preview answers its seat-membership check from the
+cached immutable seat list and scores against the cached engine game — **no `GetGame` on a
+warm hit**. `GetGame` itself was also folded from two round-trips (game, then seats) into a
+single `LEFT JOIN`. Measured at 500 players, **`game.evaluate` p99 halved (200 → 100 ms)**
+and the per-operation query count dropped.
+
+It did **not** cut postgres CPU, and the measurement says why: postgres is **write-bound**,
+not read-bound. `pg_stat_user_tables` puts the cost in the per-move `CommitMove`
+transaction (a `game_moves` insert plus `games` / `game_players` updates), the debounced
+`game_drafts` upserts (~60 k in one run), and the journal replays — not the cheap, indexed,
+fully-cached `GetGame` lookups this change removed (one re-run even committed 28 % more
+plays, whose extra writes masked the saved reads). Postgres also runs with headroom
+(~1.5 of 2 cores), and the gateway fix freed ~3 cores on the box, so the lever if postgres
+ever caps is **more cores** (it is CPU-bound, not I/O), not riskier write-path surgery. So
+this change is a latency / query-volume win, deliberately not a DB-CPU one.
+
+## Caveat — harness fidelity
+
+The harness's `not_your_turn` and `illegal_play` on `submit_play` are concurrent-play
+artifacts, not system errors: it generates a move from a locally replayed board, and a
+fast opponent (or a transport hiccup) can move between the state fetch and the submit,
+leaving the move out of turn or illegal on the now-changed board. A real client previews
+with `evaluate` and only submits a legal, in-turn play. These rejections are cheap domain
+outcomes (HTTP-ok with a stable code) and do not change the request *load*, which is what
+the run measures. The harness also shares the host CPU with the contour (capped with
+`--cpus`); a fully isolated ceiling on separate hardware remains future work.
+
+## Re-running
+
+From the repo root:
+
+```sh
+docker build -f loadtest/Dockerfile -t scrabble-loadtest .
+docker run --rm --cpus=3 --name scrabble-loadtest --network scrabble-internal \
+  -e POSTGRES_PASSWORD="$TEST_POSTGRES_PASSWORD" scrabble-loadtest run --reset --cleanup
+```
+
+`--eval=false` reproduces the pre-evaluate baseline for comparison. The authoritative hard
+reset of the contour DB remains `DROP SCHEMA backend CASCADE` + a backend restart.

loadtest/cmd/loadtest/main.go

@@ -73,6 +73,8 @@ func cmdRun(ctx context.Context, log *slog.Logger, args []string) error {
 	gpp := fs.Int("games-per-player", 0, "target concurrent games per player (0 => random 3..5)")
 	tick := fs.Duration("tick", 800*time.Millisecond, "per-player operation cadence")
 	secProb := fs.Float64("secondary-prob", 0.08, "chance per tick of a non-move operation")
+	eval := fs.Bool("eval", true, "model the per-tile evaluate preview (the realistic gameplay hot path); --eval=false reproduces the pre-evaluate harness for an A/B baseline")
+	evalRecon := fs.Int("eval-recon", 1, "extra full-composition evaluate re-previews per play (reconsideration), beyond one per placed tile")
 	hammerWorkers := fs.Int("hammer-workers", 20, "gateway-hammer concurrent callers (0 disables)")
 	hammerDur := fs.Duration("hammer-dur", 15*time.Second, "gateway-hammer duration")
 	reset := fs.Bool("reset", false, "delete prior harness rows before seeding")
@@ -117,6 +119,7 @@ func cmdRun(ctx context.Context, log *slog.Logger, args []string) error {
 	cfg := scenario.RealisticConfig{
 		Steps: steps, StepDur: *stepDur, GamesPerPlayer: *gpp,
 		Tick: *tick, SecondaryProb: *secProb,
+		Eval: *eval, EvalRecon: *evalRecon,
 	}
 	if err := drv.RunRealistic(ctx, pool, cfg); err != nil && !errors.Is(err, context.Canceled) {
 		return err

loadtest/internal/edge/client.go

@@ -24,6 +24,7 @@ const (
 	msgSubmitPlay = "game.submit_play"
 	msgPass       = "game.pass"
 	msgExchange   = "game.exchange"
+	msgEvaluate   = "game.evaluate"
 	msgState      = "game.state"
 	msgHistory    = "game.history"
 	msgGamesList  = "games.list"

loadtest/internal/edge/encode.go

@@ -63,6 +63,33 @@ func submitPlay(gameID string, tiles []PlayTile) []byte {
 	return b.FinishedBytes()
 }
 
+// evalReq builds an EvalRequest payload (game id plus the tentative newly-placed tiles).
+// It mirrors submitPlay's shape — the backend infers the play's orientation the same way —
+// so a preview previews exactly what submitting those tiles would score.
+func evalReq(gameID string, tiles []PlayTile) []byte {
+	b := flatbuffers.NewBuilder(256)
+	gid := b.CreateString(gameID)
+	offs := make([]flatbuffers.UOffsetT, len(tiles))
+	for i, t := range tiles {
+		fb.PlayTileStart(b)
+		fb.PlayTileAddRow(b, int32(t.Row))
+		fb.PlayTileAddCol(b, int32(t.Col))
+		fb.PlayTileAddLetter(b, t.Letter)
+		fb.PlayTileAddBlank(b, t.Blank)
+		offs[i] = fb.PlayTileEnd(b)
+	}
+	fb.EvalRequestStartTilesVector(b, len(offs))
+	for i := len(offs) - 1; i >= 0; i-- {
+		b.PrependUOffsetT(offs[i])
+	}
+	tilesVec := b.EndVector(len(offs))
+	fb.EvalRequestStart(b)
+	fb.EvalRequestAddGameId(b, gid)
+	fb.EvalRequestAddTiles(b, tilesVec)
+	b.Finish(fb.EvalRequestEnd(b))
+	return b.FinishedBytes()
+}
+
 // exchange builds an ExchangeRequest payload swapping the listed rack tiles (alphabet
 // indices; 255 a blank).
 func exchange(gameID string, tiles []byte) []byte {

loadtest/internal/edge/ops.go

@@ -53,6 +53,15 @@ func (c *Client) Exchange(ctx context.Context, token, gameID string, tiles []byt
 	return decodeMoveResultGame(r.Payload), r.Code, nil
 }
 
+// Evaluate previews a tentative play's legality and score without committing it. It is
+// the per-tile composition call a real client fires (debounced) on every change while
+// arranging a word, so it is the hottest gameplay request at scale. The harness records
+// only the result code and latency; an illegal preview is a successful "ok" call.
+func (c *Client) Evaluate(ctx context.Context, token, gameID string, tiles []PlayTile) (string, error) {
+	r, err := c.execute(ctx, token, msgEvaluate, evalReq(gameID, tiles))
+	return r.Code, err
+}
+
 // Nudge prods the opponent whose turn it is.
 func (c *Client) Nudge(ctx context.Context, token, gameID string) (string, error) {
 	r, err := c.execute(ctx, token, msgNudge, gameAction(gameID))

loadtest/internal/scenario/scenario.go

@@ -42,19 +42,35 @@ type RealisticConfig struct {
 	GamesPerPlayer int           // target concurrent games per player; 0 => random 3..5
 	Tick           time.Duration // per-player operation cadence (keeps a player under the per-user limit)
 	SecondaryProb  float64       // chance per tick of a non-move operation
+	Eval           bool          // model the per-tile evaluate preview (the gameplay hot path); false reproduces the pre-evaluate harness
+	EvalRecon      int           // extra full-composition evaluate re-previews per play, beyond one per placed tile
 }
 
 // DefaultRealistic returns the moderate ramp: 50 -> 200
-// -> 500 concurrent players, ~12 minutes per step, ~1 op/s per player.
+// -> 500 concurrent players, ~12 minutes per step, ~1 op/s per player, with the
+// per-tile evaluate preview modelled (the realistic hot path).
 func DefaultRealistic() RealisticConfig {
 	return RealisticConfig{
 		Steps:         []int{50, 200, 500},
 		StepDur:       12 * time.Minute,
 		Tick:          800 * time.Millisecond,
 		SecondaryProb: 0.08,
+		Eval:          true,
+		EvalRecon:     1,
 	}
 }
 
+// evalGapBase and evalGapSpan bound the modelled pause between successive tile
+// placements: the client's 250 ms debounce coalesces faster drags into a single
+// evaluate, so a thoughtful player's previews are spaced by a gap drawn from
+// [base, base+span] — wide enough that a normal composition stays under the per-user
+// rate limit, the way a real one does (the limiter's cost is measured by the hammer,
+// not by self-inflicted rejections here).
+const (
+	evalGapBase = 250 * time.Millisecond
+	evalGapSpan = 500 * time.Millisecond
+)
+
 // RunRealistic runs the staged ramp. Each step activates more players (drawn from the
 // seeded pool), assembles a cohort of games for them and starts their turn loops; the
 // loops run until the whole ramp ends. Players from earlier steps keep playing, so
@@ -128,7 +144,7 @@ func (d *Driver) playerLoop(ctx context.Context, p seed.Account, games []*Game,
 				d.secondaryOp(ctx, c, p, g, rng)
 				continue
 			}
-			if d.playTurn(ctx, c, p, g, rng) {
+			if d.playTurn(ctx, c, p, g, cfg, rng) {
 				active = slices.DeleteFunc(active, func(x *Game) bool { return x == g })
 				gi = 0
 				if len(active) == 0 {
@@ -161,10 +177,10 @@ func (d *Driver) subscribeLoop(ctx context.Context, c *edge.Client, p seed.Accou
 }
 
 // playTurn plays one turn in g over the player's client when it is the player's
-// move: fetch state, replay history, pick a legal move and submit it (or exchange /
-// pass). It reports whether the game has finished, so the caller can drop it from the
-// rotation.
-func (d *Driver) playTurn(ctx context.Context, c *edge.Client, p seed.Account, g *Game, rng *rand.Rand) (finished bool) {
+// move: fetch state, replay history, pick a legal move, compose it (the per-tile
+// evaluate previews a real client fires) and submit it (or exchange / pass). It reports
+// whether the game has finished, so the caller can drop it from the rotation.
+func (d *Driver) playTurn(ctx context.Context, c *edge.Client, p seed.Account, g *Game, cfg RealisticConfig, rng *rand.Rand) (finished bool) {
 	seat := g.seatOf(p.ID.String())
 	if seat < 0 {
 		return false
@@ -196,6 +212,7 @@ func (d *Driver) playTurn(ctx context.Context, c *edge.Client, p seed.Account, g
 	}
 	switch action.Kind {
 	case "play":
+		d.composePlay(ctx, c, p, g, action.Tiles, cfg, rng)
 		t0 = time.Now()
 		_, code, _ := c.SubmitPlay(ctx, p.Token, g.ID, action.Tiles)
 		d.rec.Record("game.submit_play", code, time.Since(t0))
@@ -211,6 +228,59 @@ func (d *Driver) playTurn(ctx context.Context, c *edge.Client, p seed.Account, g
 	return false
 }
 
+// composePlay models a player arranging the chosen play tile by tile before committing:
+// the debounced evaluate preview the real client fires on each placement (a growing prefix
+// of the tiles), a few full-composition re-previews for reconsideration (recall a tile, try
+// another spot), and the single draft persistence the client debounces out. evaluate is the
+// hottest gameplay request at scale, so omitting it (the pre-evaluate harness) understated
+// the load; cfg.Eval false reproduces that baseline for an A/B comparison. Every step
+// honours ctx, so end-of-run cancellation never blocks on a sleep or an in-flight preview.
+func (d *Driver) composePlay(ctx context.Context, c *edge.Client, p seed.Account, g *Game, tiles []edge.PlayTile, cfg RealisticConfig, rng *rand.Rand) {
+	if !cfg.Eval || len(tiles) == 0 {
+		return
+	}
+	// One evaluate per landed tile: the growing prefix mirrors the client re-previewing
+	// after each placement (an early prefix is often illegal, which is still a successful
+	// "ok" round trip — exactly the backend work a real composition triggers).
+	for n := 1; n <= len(tiles); n++ {
+		if !jitterSleep(ctx, rng, evalGapBase, evalGapSpan) {
+			return
+		}
+		t0 := time.Now()
+		code, _ := c.Evaluate(ctx, p.Token, g.ID, tiles[:n])
+		d.rec.Record("game.evaluate", code, time.Since(t0))
+	}
+	for r := 0; r < cfg.EvalRecon; r++ {
+		if !jitterSleep(ctx, rng, evalGapBase, evalGapSpan) {
+			return
+		}
+		t0 := time.Now()
+		code, _ := c.Evaluate(ctx, p.Token, g.ID, tiles)
+		d.rec.Record("game.evaluate", code, time.Since(t0))
+	}
+	// The client persists the in-progress composition (debounced to one upsert). Its opaque
+	// JSON content does not affect the call's cost, so a minimal valid shape stands in.
+	t0 := time.Now()
+	code, _ := c.DraftSave(ctx, p.Token, g.ID, `{"rack_order":"","board_tiles":[]}`)
+	d.rec.Record("draft.save", code, time.Since(t0))
+}
+
+// jitterSleep pauses for a randomised gap in [base, base+span], modelling the human pause
+// between tile placements that the client's debounce coalesces into one evaluate. It
+// returns false if ctx is cancelled during the wait, so a composition unwinds promptly at
+// end of run.
+func jitterSleep(ctx context.Context, rng *rand.Rand, base, span time.Duration) bool {
+	d := base + time.Duration(rng.Int63n(int64(span)+1))
+	t := time.NewTimer(d)
+	defer t.Stop()
+	select {
+	case <-ctx.Done():
+		return false
+	case <-t.C:
+		return true
+	}
+}
+
 // secondaryOp exercises one of the non-move edge operations the plan calls out, so
 // the run touches nudge / chat / check-word / draft / profile / stats too, over the
 // player's own client.

pkg/proto/botlink/v1/botlink.pb.go

@@ -224,6 +224,7 @@ type Command struct {
 	//	*Command_Notify
 	//	*Command_SendToUser
 	//	*Command_SendToChannel
+	//	*Command_ChatGate
 	Payload       isCommand_Payload `protobuf_oneof:"payload"`
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
@@ -300,6 +301,15 @@ func (x *Command) GetSendToChannel() *v1.SendToGameChannelRequest {
 	return nil
 }
 
+func (x *Command) GetChatGate() *ChatGateCommand {
+	if x != nil {
+		if x, ok := x.Payload.(*Command_ChatGate); ok {
+			return x.ChatGate
+		}
+	}
+	return nil
+}
+
 type isCommand_Payload interface {
 	isCommand_Payload()
 }
@@ -316,12 +326,18 @@ type Command_SendToChannel struct {
 	SendToChannel *v1.SendToGameChannelRequest `protobuf:"bytes,4,opt,name=send_to_channel,json=sendToChannel,proto3,oneof"`
 }
 
+type Command_ChatGate struct {
+	ChatGate *ChatGateCommand `protobuf:"bytes,5,opt,name=chat_gate,json=chatGate,proto3,oneof"`
+}
+
 func (*Command_Notify) isCommand_Payload() {}
 
 func (*Command_SendToUser) isCommand_Payload() {}
 
 func (*Command_SendToChannel) isCommand_Payload() {}
 
+func (*Command_ChatGate) isCommand_Payload() {}
+
 // Ack reports the outcome of the Command with command_id. delivered mirrors the
 // connector delivery semantics (false when the kind is not rendered out-of-app, the
 // user never started the bot, or no channel is configured); error carries an
@@ -386,6 +402,166 @@ func (x *Ack) GetError() string {
 	return ""
 }
 
+// ChatGateCommand sets a Telegram user's write access in the moderated discussion
+// chat. external_id is the user's Telegram identity (as in the backend identities
+// table); allow grants the right to write when true and revokes it when false. The
+// bot applies it only to a user currently in the chat — it guards on getChatMember,
+// so a command for an absent user is a no-op. The gateway emits one whenever the
+// user's eligibility may have changed: an admin block or unblock, a chat_muted
+// grant or revoke, or a temporary block lapsing.
+type ChatGateCommand struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	ExternalId    string                 `protobuf:"bytes,1,opt,name=external_id,json=externalId,proto3" json:"external_id,omitempty"`
+	Allow         bool                   `protobuf:"varint,2,opt,name=allow,proto3" json:"allow,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *ChatGateCommand) Reset() {
+	*x = ChatGateCommand{}
+	mi := &file_botlink_v1_botlink_proto_msgTypes[5]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *ChatGateCommand) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ChatGateCommand) ProtoMessage() {}
+
+func (x *ChatGateCommand) ProtoReflect() protoreflect.Message {
+	mi := &file_botlink_v1_botlink_proto_msgTypes[5]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ChatGateCommand.ProtoReflect.Descriptor instead.
+func (*ChatGateCommand) Descriptor() ([]byte, []int) {
+	return file_botlink_v1_botlink_proto_rawDescGZIP(), []int{5}
+}
+
+func (x *ChatGateCommand) GetExternalId() string {
+	if x != nil {
+		return x.ExternalId
+	}
+	return ""
+}
+
+func (x *ChatGateCommand) GetAllow() bool {
+	if x != nil {
+		return x.Allow
+	}
+	return false
+}
+
+// ChatEligibilityRequest asks whether the Telegram user identified by external_id
+// may write in the moderated discussion chat.
+type ChatEligibilityRequest struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	ExternalId    string                 `protobuf:"bytes,1,opt,name=external_id,json=externalId,proto3" json:"external_id,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *ChatEligibilityRequest) Reset() {
+	*x = ChatEligibilityRequest{}
+	mi := &file_botlink_v1_botlink_proto_msgTypes[6]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *ChatEligibilityRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ChatEligibilityRequest) ProtoMessage() {}
+
+func (x *ChatEligibilityRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_botlink_v1_botlink_proto_msgTypes[6]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ChatEligibilityRequest.ProtoReflect.Descriptor instead.
+func (*ChatEligibilityRequest) Descriptor() ([]byte, []int) {
+	return file_botlink_v1_botlink_proto_rawDescGZIP(), []int{6}
+}
+
+func (x *ChatEligibilityRequest) GetExternalId() string {
+	if x != nil {
+		return x.ExternalId
+	}
+	return ""
+}
+
+// ChatEligibilityResponse is the eligibility answer. registered reports whether the
+// external_id maps to an account at all; eligible is the final gate the bot acts on
+// (registered and neither admin-suspended nor chat-muted).
+type ChatEligibilityResponse struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	Registered    bool                   `protobuf:"varint,1,opt,name=registered,proto3" json:"registered,omitempty"`
+	Eligible      bool                   `protobuf:"varint,2,opt,name=eligible,proto3" json:"eligible,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *ChatEligibilityResponse) Reset() {
+	*x = ChatEligibilityResponse{}
+	mi := &file_botlink_v1_botlink_proto_msgTypes[7]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *ChatEligibilityResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ChatEligibilityResponse) ProtoMessage() {}
+
+func (x *ChatEligibilityResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_botlink_v1_botlink_proto_msgTypes[7]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ChatEligibilityResponse.ProtoReflect.Descriptor instead.
+func (*ChatEligibilityResponse) Descriptor() ([]byte, []int) {
+	return file_botlink_v1_botlink_proto_rawDescGZIP(), []int{7}
+}
+
+func (x *ChatEligibilityResponse) GetRegistered() bool {
+	if x != nil {
+		return x.Registered
+	}
+	return false
+}
+
+func (x *ChatEligibilityResponse) GetEligible() bool {
+	if x != nil {
+		return x.Eligible
+	}
+	return false
+}
+
 var File_botlink_v1_botlink_proto protoreflect.FileDescriptor
 
 const file_botlink_v1_botlink_proto_rawDesc = "" +
@@ -400,22 +576,36 @@ const file_botlink_v1_botlink_proto_rawDesc = "" +
 	"\x05Hello\x12\x1f\n" +
 	"\vinstance_id\x18\x01 \x01(\tR\n" +
 	"instanceId\x12!\n" +
-	"\fowns_updates\x18\x02 \x01(\bR\vownsUpdates\"\x99\x02\n" +
+	"\fowns_updates\x18\x02 \x01(\bR\vownsUpdates\"\xde\x02\n" +
 	"\aCommand\x12\x1d\n" +
 	"\n" +
 	"command_id\x18\x01 \x01(\tR\tcommandId\x12=\n" +
 	"\x06notify\x18\x02 \x01(\v2#.scrabble.telegram.v1.NotifyRequestH\x00R\x06notify\x12K\n" +
 	"\fsend_to_user\x18\x03 \x01(\v2'.scrabble.telegram.v1.SendToUserRequestH\x00R\n" +
 	"sendToUser\x12X\n" +
-	"\x0fsend_to_channel\x18\x04 \x01(\v2..scrabble.telegram.v1.SendToGameChannelRequestH\x00R\rsendToChannelB\t\n" +
+	"\x0fsend_to_channel\x18\x04 \x01(\v2..scrabble.telegram.v1.SendToGameChannelRequestH\x00R\rsendToChannel\x12C\n" +
+	"\tchat_gate\x18\x05 \x01(\v2$.scrabble.botlink.v1.ChatGateCommandH\x00R\bchatGateB\t\n" +
 	"\apayload\"X\n" +
 	"\x03Ack\x12\x1d\n" +
 	"\n" +
 	"command_id\x18\x01 \x01(\tR\tcommandId\x12\x1c\n" +
 	"\tdelivered\x18\x02 \x01(\bR\tdelivered\x12\x14\n" +
-	"\x05error\x18\x03 \x01(\tR\x05error2O\n" +
+	"\x05error\x18\x03 \x01(\tR\x05error\"H\n" +
+	"\x0fChatGateCommand\x12\x1f\n" +
+	"\vexternal_id\x18\x01 \x01(\tR\n" +
+	"externalId\x12\x14\n" +
+	"\x05allow\x18\x02 \x01(\bR\x05allow\"9\n" +
+	"\x16ChatEligibilityRequest\x12\x1f\n" +
+	"\vexternal_id\x18\x01 \x01(\tR\n" +
+	"externalId\"U\n" +
+	"\x17ChatEligibilityResponse\x12\x1e\n" +
+	"\n" +
+	"registered\x18\x01 \x01(\bR\n" +
+	"registered\x12\x1a\n" +
+	"\beligible\x18\x02 \x01(\bR\beligible2\xc4\x01\n" +
 	"\aBotLink\x12D\n" +
-	"\x04Link\x12\x1c.scrabble.botlink.v1.FromBot\x1a\x1a.scrabble.botlink.v1.ToBot(\x010\x01B)Z'scrabble/pkg/proto/botlink/v1;botlinkv1b\x06proto3"
+	"\x04Link\x12\x1c.scrabble.botlink.v1.FromBot\x1a\x1a.scrabble.botlink.v1.ToBot(\x010\x01\x12s\n" +
+	"\x16ResolveChatEligibility\x12+.scrabble.botlink.v1.ChatEligibilityRequest\x1a,.scrabble.botlink.v1.ChatEligibilityResponseB)Z'scrabble/pkg/proto/botlink/v1;botlinkv1b\x06proto3"
 
 var (
 	file_botlink_v1_botlink_proto_rawDescOnce sync.Once
@@ -429,31 +619,37 @@ func file_botlink_v1_botlink_proto_rawDescGZIP() []byte {
 	return file_botlink_v1_botlink_proto_rawDescData
 }
 
-var file_botlink_v1_botlink_proto_msgTypes = make([]protoimpl.MessageInfo, 5)
+var file_botlink_v1_botlink_proto_msgTypes = make([]protoimpl.MessageInfo, 8)
 var file_botlink_v1_botlink_proto_goTypes = []any{
 	(*FromBot)(nil),                     // 0: scrabble.botlink.v1.FromBot
 	(*ToBot)(nil),                       // 1: scrabble.botlink.v1.ToBot
 	(*Hello)(nil),                       // 2: scrabble.botlink.v1.Hello
 	(*Command)(nil),                     // 3: scrabble.botlink.v1.Command
 	(*Ack)(nil),                         // 4: scrabble.botlink.v1.Ack
-	(*v1.NotifyRequest)(nil),            // 5: scrabble.telegram.v1.NotifyRequest
-	(*v1.SendToUserRequest)(nil),        // 6: scrabble.telegram.v1.SendToUserRequest
-	(*v1.SendToGameChannelRequest)(nil), // 7: scrabble.telegram.v1.SendToGameChannelRequest
+	(*ChatGateCommand)(nil),             // 5: scrabble.botlink.v1.ChatGateCommand
+	(*ChatEligibilityRequest)(nil),      // 6: scrabble.botlink.v1.ChatEligibilityRequest
+	(*ChatEligibilityResponse)(nil),     // 7: scrabble.botlink.v1.ChatEligibilityResponse
+	(*v1.NotifyRequest)(nil),            // 8: scrabble.telegram.v1.NotifyRequest
+	(*v1.SendToUserRequest)(nil),        // 9: scrabble.telegram.v1.SendToUserRequest
+	(*v1.SendToGameChannelRequest)(nil), // 10: scrabble.telegram.v1.SendToGameChannelRequest
 }
 var file_botlink_v1_botlink_proto_depIdxs = []int32{
 	2,  // 0: scrabble.botlink.v1.FromBot.hello:type_name -> scrabble.botlink.v1.Hello
 	4,  // 1: scrabble.botlink.v1.FromBot.ack:type_name -> scrabble.botlink.v1.Ack
 	3,  // 2: scrabble.botlink.v1.ToBot.command:type_name -> scrabble.botlink.v1.Command
-	5, // 3: scrabble.botlink.v1.Command.notify:type_name -> scrabble.telegram.v1.NotifyRequest
-	6, // 4: scrabble.botlink.v1.Command.send_to_user:type_name -> scrabble.telegram.v1.SendToUserRequest
-	7, // 5: scrabble.botlink.v1.Command.send_to_channel:type_name -> scrabble.telegram.v1.SendToGameChannelRequest
-	0, // 6: scrabble.botlink.v1.BotLink.Link:input_type -> scrabble.botlink.v1.FromBot
-	1, // 7: scrabble.botlink.v1.BotLink.Link:output_type -> scrabble.botlink.v1.ToBot
-	7, // [7:8] is the sub-list for method output_type
-	6, // [6:7] is the sub-list for method input_type
-	6, // [6:6] is the sub-list for extension type_name
-	6, // [6:6] is the sub-list for extension extendee
-	0, // [0:6] is the sub-list for field type_name
+	8,  // 3: scrabble.botlink.v1.Command.notify:type_name -> scrabble.telegram.v1.NotifyRequest
+	9,  // 4: scrabble.botlink.v1.Command.send_to_user:type_name -> scrabble.telegram.v1.SendToUserRequest
+	10, // 5: scrabble.botlink.v1.Command.send_to_channel:type_name -> scrabble.telegram.v1.SendToGameChannelRequest
+	5,  // 6: scrabble.botlink.v1.Command.chat_gate:type_name -> scrabble.botlink.v1.ChatGateCommand
+	0,  // 7: scrabble.botlink.v1.BotLink.Link:input_type -> scrabble.botlink.v1.FromBot
+	6,  // 8: scrabble.botlink.v1.BotLink.ResolveChatEligibility:input_type -> scrabble.botlink.v1.ChatEligibilityRequest
+	1,  // 9: scrabble.botlink.v1.BotLink.Link:output_type -> scrabble.botlink.v1.ToBot
+	7,  // 10: scrabble.botlink.v1.BotLink.ResolveChatEligibility:output_type -> scrabble.botlink.v1.ChatEligibilityResponse
+	9,  // [9:11] is the sub-list for method output_type
+	7,  // [7:9] is the sub-list for method input_type
+	7,  // [7:7] is the sub-list for extension type_name
+	7,  // [7:7] is the sub-list for extension extendee
+	0,  // [0:7] is the sub-list for field type_name
 }
 
 func init() { file_botlink_v1_botlink_proto_init() }
@@ -469,6 +665,7 @@ func file_botlink_v1_botlink_proto_init() {
 		(*Command_Notify)(nil),
 		(*Command_SendToUser)(nil),
 		(*Command_SendToChannel)(nil),
+		(*Command_ChatGate)(nil),
 	}
 	type x struct{}
 	out := protoimpl.TypeBuilder{
@@ -476,7 +673,7 @@ func file_botlink_v1_botlink_proto_init() {
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: unsafe.Slice(unsafe.StringData(file_botlink_v1_botlink_proto_rawDesc), len(file_botlink_v1_botlink_proto_rawDesc)),
 			NumEnums:      0,
-			NumMessages:   5,
+			NumMessages:   8,
 			NumExtensions: 0,
 			NumServices:   1,
 		},

pkg/proto/botlink/v1/botlink.proto

@@ -20,6 +20,13 @@ service BotLink {
   // Link opens the single bot <-> gateway stream. The first client message is
   // Hello; thereafter the client sends one Ack per received Command.
   rpc Link(stream FromBot) returns (stream ToBot);
+
+  // ResolveChatEligibility answers whether the Telegram user identified by
+  // external_id may write in the moderated discussion chat: registered with an
+  // account and neither admin-suspended nor chat-muted. The bot calls it over the
+  // same mTLS channel when a user joins the chat, to decide whether to grant the
+  // write permission. Delivery of the answer is request/response (not best-effort).
+  rpc ResolveChatEligibility(ChatEligibilityRequest) returns (ChatEligibilityResponse);
 }
 
 // FromBot is a message the bot sends to the gateway: the opening Hello, then one
@@ -53,6 +60,7 @@ message Command {
     scrabble.telegram.v1.NotifyRequest notify = 2;
     scrabble.telegram.v1.SendToUserRequest send_to_user = 3;
     scrabble.telegram.v1.SendToGameChannelRequest send_to_channel = 4;
+    ChatGateCommand chat_gate = 5;
   }
 }
 
@@ -65,3 +73,29 @@ message Ack {
   bool delivered = 2;
   string error = 3;
 }
+
+// ChatGateCommand sets a Telegram user's write access in the moderated discussion
+// chat. external_id is the user's Telegram identity (as in the backend identities
+// table); allow grants the right to write when true and revokes it when false. The
+// bot applies it only to a user currently in the chat — it guards on getChatMember,
+// so a command for an absent user is a no-op. The gateway emits one whenever the
+// user's eligibility may have changed: an admin block or unblock, a chat_muted
+// grant or revoke, or a temporary block lapsing.
+message ChatGateCommand {
+  string external_id = 1;
+  bool allow = 2;
+}
+
+// ChatEligibilityRequest asks whether the Telegram user identified by external_id
+// may write in the moderated discussion chat.
+message ChatEligibilityRequest {
+  string external_id = 1;
+}
+
+// ChatEligibilityResponse is the eligibility answer. registered reports whether the
+// external_id maps to an account at all; eligible is the final gate the bot acts on
+// (registered and neither admin-suspended nor chat-muted).
+message ChatEligibilityResponse {
+  bool registered = 1;
+  bool eligible = 2;
+}

pkg/proto/botlink/v1/botlink_grpc.pb.go

@@ -27,6 +27,7 @@ const _ = grpc.SupportPackageIsVersion9
 
 const (
 	BotLink_Link_FullMethodName                   = "/scrabble.botlink.v1.BotLink/Link"
+	BotLink_ResolveChatEligibility_FullMethodName = "/scrabble.botlink.v1.BotLink/ResolveChatEligibility"
 )
 
 // BotLinkClient is the client API for BotLink service.
@@ -41,6 +42,12 @@ type BotLinkClient interface {
 	// Link opens the single bot <-> gateway stream. The first client message is
 	// Hello; thereafter the client sends one Ack per received Command.
 	Link(ctx context.Context, opts ...grpc.CallOption) (grpc.BidiStreamingClient[FromBot, ToBot], error)
+	// ResolveChatEligibility answers whether the Telegram user identified by
+	// external_id may write in the moderated discussion chat: registered with an
+	// account and neither admin-suspended nor chat-muted. The bot calls it over the
+	// same mTLS channel when a user joins the chat, to decide whether to grant the
+	// write permission. Delivery of the answer is request/response (not best-effort).
+	ResolveChatEligibility(ctx context.Context, in *ChatEligibilityRequest, opts ...grpc.CallOption) (*ChatEligibilityResponse, error)
 }
 
 type botLinkClient struct {
@@ -64,6 +71,16 @@ func (c *botLinkClient) Link(ctx context.Context, opts ...grpc.CallOption) (grpc
 // This type alias is provided for backwards compatibility with existing code that references the prior non-generic stream type by name.
 type BotLink_LinkClient = grpc.BidiStreamingClient[FromBot, ToBot]
 
+func (c *botLinkClient) ResolveChatEligibility(ctx context.Context, in *ChatEligibilityRequest, opts ...grpc.CallOption) (*ChatEligibilityResponse, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(ChatEligibilityResponse)
+	err := c.cc.Invoke(ctx, BotLink_ResolveChatEligibility_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 // BotLinkServer is the server API for BotLink service.
 // All implementations must embed UnimplementedBotLinkServer
 // for forward compatibility.
@@ -76,6 +93,12 @@ type BotLinkServer interface {
 	// Link opens the single bot <-> gateway stream. The first client message is
 	// Hello; thereafter the client sends one Ack per received Command.
 	Link(grpc.BidiStreamingServer[FromBot, ToBot]) error
+	// ResolveChatEligibility answers whether the Telegram user identified by
+	// external_id may write in the moderated discussion chat: registered with an
+	// account and neither admin-suspended nor chat-muted. The bot calls it over the
+	// same mTLS channel when a user joins the chat, to decide whether to grant the
+	// write permission. Delivery of the answer is request/response (not best-effort).
+	ResolveChatEligibility(context.Context, *ChatEligibilityRequest) (*ChatEligibilityResponse, error)
 	mustEmbedUnimplementedBotLinkServer()
 }
 
@@ -89,6 +112,9 @@ type UnimplementedBotLinkServer struct{}
 func (UnimplementedBotLinkServer) Link(grpc.BidiStreamingServer[FromBot, ToBot]) error {
 	return status.Errorf(codes.Unimplemented, "method Link not implemented")
 }
+func (UnimplementedBotLinkServer) ResolveChatEligibility(context.Context, *ChatEligibilityRequest) (*ChatEligibilityResponse, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method ResolveChatEligibility not implemented")
+}
 func (UnimplementedBotLinkServer) mustEmbedUnimplementedBotLinkServer() {}
 func (UnimplementedBotLinkServer) testEmbeddedByValue()                 {}
 
@@ -117,13 +143,36 @@ func _BotLink_Link_Handler(srv interface{}, stream grpc.ServerStream) error {
 // This type alias is provided for backwards compatibility with existing code that references the prior non-generic stream type by name.
 type BotLink_LinkServer = grpc.BidiStreamingServer[FromBot, ToBot]
 
+func _BotLink_ResolveChatEligibility_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(ChatEligibilityRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(BotLinkServer).ResolveChatEligibility(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: BotLink_ResolveChatEligibility_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(BotLinkServer).ResolveChatEligibility(ctx, req.(*ChatEligibilityRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
 // BotLink_ServiceDesc is the grpc.ServiceDesc for BotLink service.
 // It's only intended for direct use with grpc.RegisterService,
 // and not to be introspected or modified (even as a copy)
 var BotLink_ServiceDesc = grpc.ServiceDesc{
 	ServiceName: "scrabble.botlink.v1.BotLink",
 	HandlerType: (*BotLinkServer)(nil),
-	Methods:     []grpc.MethodDesc{},
+	Methods: []grpc.MethodDesc{
+		{
+			MethodName: "ResolveChatEligibility",
+			Handler:    _BotLink_ResolveChatEligibility_Handler,
+		},
+	},
 	Streams: []grpc.StreamDesc{
 		{
 			StreamName:    "Link",

pkg/telemetry/telemetry.go

@@ -29,6 +29,8 @@ import (
 	"go.opentelemetry.io/otel/sdk/resource"
 	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 	"go.opentelemetry.io/otel/trace"
+
+	"scrabble/pkg/version"
 )
 
 // Exporter selectors supported per signal.
@@ -95,9 +97,7 @@ func New(ctx context.Context, cfg Config) (*Runtime, error) {
 		return nil, err
 	}
 
-	res, err := resource.New(ctx, resource.WithAttributes(
-		attribute.String("service.name", cfg.ServiceName),
-	))
+	res, err := serviceResource(ctx, cfg)
 	if err != nil {
 		return nil, fmt.Errorf("telemetry: build resource: %w", err)
 	}
@@ -122,6 +122,16 @@ func New(ctx context.Context, cfg Config) (*Runtime, error) {
 	return &Runtime{tracerProvider: tracerProvider, meterProvider: meterProvider}, nil
 }
 
+// serviceResource builds the OpenTelemetry resource describing this service: its
+// service.name and the service.version stamped into the binary at build time
+// (pkg/version, set from the git tag by the deploy).
+func serviceResource(ctx context.Context, cfg Config) (*resource.Resource, error) {
+	return resource.New(ctx, resource.WithAttributes(
+		attribute.String("service.name", cfg.ServiceName),
+		attribute.String("service.version", version.Version),
+	))
+}
+
 // TracerProvider returns the runtime tracer provider, or the global one when r is
 // not initialised.
 func (r *Runtime) TracerProvider() trace.TracerProvider {

pkg/telemetry/telemetry_test.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"testing"
 	"time"
+
+	"scrabble/pkg/version"
 )
 
 // TestConfigValidate covers the supported and rejected exporter selections.
@@ -82,3 +84,22 @@ func TestNilRuntime(t *testing.T) {
 		t.Errorf("nil runtime Shutdown: %v", err)
 	}
 }
+
+// TestServiceResource checks the resource carries service.name and the embedded
+// service.version (pkg/version, stamped at build time).
+func TestServiceResource(t *testing.T) {
+	res, err := serviceResource(context.Background(), DefaultConfig("svc"))
+	if err != nil {
+		t.Fatalf("serviceResource: %v", err)
+	}
+	attrs := map[string]string{}
+	for _, kv := range res.Attributes() {
+		attrs[string(kv.Key)] = kv.Value.AsString()
+	}
+	if attrs["service.name"] != "svc" {
+		t.Errorf("service.name = %q, want svc", attrs["service.name"])
+	}
+	if attrs["service.version"] != version.Version {
+		t.Errorf("service.version = %q, want %q", attrs["service.version"], version.Version)
+	}
+}

pkg/version/version.go

@@ -0,0 +1,10 @@
+// Package version exposes the build version stamped into every Scrabble service
+// binary. The default is "dev"; release builds override it through the linker
+// (`go build -ldflags "-X scrabble/pkg/version.Version=<value>"`), wired from the
+// VERSION build-arg in each service Dockerfile, which the deploy sets to the git
+// tag (`git describe --tags`). It surfaces as the OpenTelemetry service.version
+// resource attribute (see pkg/telemetry) and the SPA About screen.
+package version
+
+// Version is the build version, "dev" unless overridden at link time.
+var Version = "dev"

platform/telegram/Dockerfile

@@ -19,8 +19,10 @@ COPY platform/telegram ./platform/telegram
 # Reduce the workspace to what the platform needs: only pkg + platform/telegram.
 RUN go work edit -dropuse=./backend -dropuse=./gateway -dropuse=./loadtest -dropreplace=scrabble/gateway@v0.0.0 -dropreplace=scrabble-solver
 
-RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -o /out/validator ./platform/telegram/cmd/validator
-RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -o /out/bot ./platform/telegram/cmd/bot
+# VERSION (the deploy passes the git tag) is stamped into both binaries via the linker.
+ARG VERSION=dev
+RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -ldflags "-X scrabble/pkg/version.Version=${VERSION}" -o /out/validator ./platform/telegram/cmd/validator
+RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -ldflags "-X scrabble/pkg/version.Version=${VERSION}" -o /out/bot ./platform/telegram/cmd/bot
 
 # --- validator (home) --------------------------------------------------------
 FROM gcr.io/distroless/static-debian12:nonroot AS validator

platform/telegram/README.md

@@ -42,6 +42,27 @@ Telegram identity to an account from a browser. Both map a rejection to gRPC
   launch button; a deep-link payload routes the launch to a game / invitation / friend
   code. This is **self-contained** — the bot never calls back into the game, so `/start`
   onboarding works even when the game is down.
+- **Moderated-chat gating.** When `TELEGRAM_CHAT_ID` names a channel's linked discussion
+  group, the bot gates who may write there. The group **allows sending by default** (a
+  human setting) and the bot only **restricts** — Telegram intersects the chat default with
+  each user's permission, so a per-user grant cannot exceed a deny-by-default group, and the
+  gate must mute the ineligible rather than grant the eligible. On a `chat_member` event the
+  bot asks the gateway (`ResolveChatEligibility`) and **mutes** a member who is not registered
+  or is admin-suspended or `chat_muted`, **un-mutes** an eligible one it had muted, and leaves
+  an already-allowed eligible member untouched (it acts only when the state differs, so it is
+  idempotent and skips its own change). When an operator blocks/unblocks an account, toggles
+  its `chat_muted` role, or a user first registers, the gateway pushes a `ChatGate` command and
+  the bot applies it — but only to a member currently in the chat (it probes one user with
+  `getChatMember`, since bots cannot list members). The bot must be an **administrator** there
+  with the **"Ban users"** right (the Bot API `can_restrict_members`), and it subscribes to
+  `chat_member` updates, which Telegram delivers only to a chat admin.
+- **Promo bot (optional).** When `TELEGRAM_PROMO_BOT_TOKEN` is set, the container also
+  runs a **second, standalone** bot whose only job is to answer `/start` with a localized
+  message and a button that opens the **main** bot's Mini App. The button is a **URL** to
+  the main bot's direct link (`TELEGRAM_BOT_LINK`, the same link the UI uses) with
+  `?startapp` — a `web_app` button would launch under the promo bot's identity (its token
+  would sign the initData), which the main bot's validator rejects. It is fully
+  self-contained: no bot-link, no gateway, no game.
 - **Rate limiting.** Outbound sends are throttled (`TELEGRAM_SEND_RATE_PER_SECOND`,
   default 25) to respect the Bot API flood limits.
 
@@ -57,7 +78,9 @@ parsing is Telegram-specific.
   gateway also implements `SendToUser` / `SendToGameChannel` as the backend's admin
   relay.
 - `pkg/proto/botlink/v1`, service `BotLink` — the reverse bidi stream the **bot** dials
-  on the gateway (`Hello` / `Command` / `Ack`). Generated Go is committed under `pkg`.
+  on the gateway (`Hello` / `Command` / `Ack`), now also carrying a `ChatGateCommand` (set
+  a user's chat write access) and a unary `ResolveChatEligibility` (the bot's join-time
+  query) over the same mTLS channel. Generated Go is committed under `pkg`.
 
 ## Deep-link scheme
 
@@ -101,6 +124,10 @@ Bot (`cmd/bot`):
 | `TELEGRAM_BOTLINK_SERVER_NAME` | — (required) | the gateway certificate's expected SNI / CN |
 | `TELEGRAM_BOTLINK_TLS_CERT` / `_KEY` / `_CA` | — (required) | the bot client cert, its key, and the CA that signs the gateway server cert |
 | `TELEGRAM_GAME_CHANNEL_ID` | — | the bot's game channel chat id for `SendToGameChannel` |
+| `TELEGRAM_CHAT_ID` | — | the moderated discussion chat id (a channel's linked group); empty disables chat gating |
+| `TELEGRAM_PROMO_BOT_TOKEN` | — | the optional standalone promo bot's token; empty disables it |
+| `TELEGRAM_BOT_USERNAME` | — | the main bot's @username without the @ (promo message); required when the promo bot runs |
+| `TELEGRAM_BOT_LINK` | — | the main bot's Mini App link for the promo button (the UI's `VITE_TELEGRAM_LINK`); required when the promo bot runs |
 | `TELEGRAM_OWNS_UPDATES` | `true` | run the exclusive `getUpdates` long-poll (one bot per token) |
 | `TELEGRAM_SEND_RATE_PER_SECOND` | `25` | outbound Bot API send cap (0 disables) |
 | `TELEGRAM_INSTANCE_ID` | hostname | bot identity reported to the gateway |

platform/telegram/cmd/bot/main.go

@@ -22,6 +22,7 @@ import (
 	"scrabble/platform/telegram/internal/bot"
 	"scrabble/platform/telegram/internal/botlink"
 	"scrabble/platform/telegram/internal/config"
+	"scrabble/platform/telegram/internal/promobot"
 )
 
 // telemetryShutdownTimeout bounds the OpenTelemetry flush during process exit.
@@ -70,6 +71,7 @@ func run(ctx context.Context, cfg config.BotConfig, logger *zap.Logger) error {
 		TestEnv:           cfg.TestEnv,
 		MiniAppURL:        cfg.MiniAppURL,
 		SendRatePerSecond: cfg.SendRatePerSecond,
+		ChatID:            cfg.ChatID,
 	}, logger)
 	if err != nil {
 		return err
@@ -80,19 +82,52 @@ func run(ctx context.Context, cfg config.BotConfig, logger *zap.Logger) error {
 		return err
 	}
 	exec := botlink.NewExecutor(b, cfg.GameChannelID, logger)
-	client := botlink.NewClient(botlink.ClientConfig{
+	client, err := botlink.NewClient(botlink.ClientConfig{
 		GatewayAddr:    cfg.BotLink.GatewayAddr,
 		InstanceID:     cfg.BotLink.InstanceID,
 		OwnsUpdates:    cfg.OwnsUpdates,
 		Creds:          credentials.NewTLS(tlsCfg),
 		ReconnectDelay: cfg.BotLink.ReconnectDelay,
 	}, exec, logger)
+	if err != nil {
+		return err
+	}
+	defer func() { _ = client.Close() }()
+	// The chat-join eligibility query rides the same bot-link connection; wire it into
+	// the bot after the client is built — the late binding that breaks the bot <->
+	// client construction cycle.
+	b.SetEligibilityResolver(client.ResolveChatEligibility)
+
+	// The optional standalone promo bot: a second bot (its own token) that only answers
+	// /start with a button opening the main bot's Mini App. It is self-contained — no
+	// bot-link, no gateway — so onboarding works even when the game is down.
+	var promo *promobot.Bot
+	if cfg.PromoBotToken != "" {
+		// The promo bot is auxiliary and shares this process with the main bot, so its
+		// construction failure (a bad or unreachable promo token — tgbot.New validates it
+		// with getMe) is logged and the promo bot is skipped, never fatal: it must not
+		// take the main game bot down with it.
+		promo, err = promobot.New(promobot.Config{
+			Token:             cfg.PromoBotToken,
+			APIBaseURL:        cfg.APIBaseURL,
+			TestEnv:           cfg.TestEnv,
+			BotUsername:       cfg.BotUsername,
+			BotLinkURL:        cfg.BotLinkURL,
+			SendRatePerSecond: cfg.SendRatePerSecond,
+		}, logger)
+		if err != nil {
+			logger.Error("promo bot disabled: construction failed (the main bot is unaffected)", zap.Error(err))
+			promo = nil
+		}
+	}
 
 	logger.Info("telegram bot starting",
 		zap.String("gateway", cfg.BotLink.GatewayAddr),
 		zap.String("miniapp_url", cfg.MiniAppURL),
 		zap.Bool("owns_updates", cfg.OwnsUpdates),
-		zap.Bool("test_env", cfg.TestEnv))
+		zap.Bool("test_env", cfg.TestEnv),
+		zap.Bool("chat_gating", cfg.ChatID != 0),
+		zap.Bool("promo_bot", promo != nil))
 
 	var wg sync.WaitGroup
 	// The long-poll holds the exclusive getUpdates lease (one bot per token); a bot
@@ -105,6 +140,11 @@ func run(ctx context.Context, cfg config.BotConfig, logger *zap.Logger) error {
 			logger.Error("bot-link client stopped", zap.Error(err))
 		}
 	})
+	// The promo bot runs its own getUpdates long-poll on its own token (no 409 with
+	// the main bot's lease).
+	if promo != nil {
+		wg.Go(func() { promo.Run(ctx) })
+	}
 
 	<-ctx.Done()
 	wg.Wait()

platform/telegram/internal/bot/bot.go

@@ -8,6 +8,7 @@ package bot
 import (
 	"context"
 	"net/url"
+	"strconv"
 	"strings"
 
 	tgbot "github.com/go-telegram/bot"
@@ -30,8 +31,19 @@ type Config struct {
 	// Telegram Bot API flood limits; 0 disables the limiter. The burst equals the
 	// per-second rate.
 	SendRatePerSecond int
+	// ChatID is the moderated discussion chat the bot gates write access in; 0
+	// disables chat gating (and the chat_member long-poll subscription). Gating needs
+	// the bot to be an administrator there with the restrict-members right.
+	ChatID int64
 }
 
+// EligibilityResolver answers whether the Telegram user identified by externalID
+// (the decimal user id) may write in the moderated chat: registered and neither
+// admin-suspended nor chat-muted. The bot calls it when a user joins the chat. It is
+// late-bound (SetEligibilityResolver) because it is backed by the bot-link client,
+// which is built after the bot.
+type EligibilityResolver func(ctx context.Context, externalID string) (eligible bool, err error)
+
 // Bot wraps a Telegram Bot API client and the Mini App launch URL.
 type Bot struct {
 	api        *tgbot.Bot
@@ -40,6 +52,14 @@ type Bot struct {
 	// limiter throttles outbound sends to stay under the Bot API flood limits; nil
 	// disables throttling.
 	limiter *rate.Limiter
+	// chatID is the moderated discussion chat (0 disables gating).
+	chatID int64
+	// botID is the bot's own Telegram user id (resolved at startup); it skips the
+	// chat_member updates the bot's own restrict actions generate — the grant loop guard.
+	botID int64
+	// eligibility resolves a joining user's chat write eligibility; nil leaves a
+	// joiner muted (fail-closed) until it is wired.
+	eligibility EligibilityResolver
 }
 
 // New builds the bot wrapper, registering the /start handler and a default handler
@@ -49,15 +69,25 @@ func New(cfg Config, log *zap.Logger) (*Bot, error) {
 	if log == nil {
 		log = zap.NewNop()
 	}
-	t := &Bot{miniAppURL: cfg.MiniAppURL, log: log}
+	t := &Bot{miniAppURL: cfg.MiniAppURL, log: log, chatID: cfg.ChatID}
 	if cfg.SendRatePerSecond > 0 {
 		t.limiter = rate.NewLimiter(rate.Limit(cfg.SendRatePerSecond), cfg.SendRatePerSecond)
 	}
 
 	opts := []tgbot.Option{
-		tgbot.WithDefaultHandler(t.handleStart),
+		tgbot.WithDefaultHandler(t.handleUpdate),
 		tgbot.WithMessageTextHandler("/start", tgbot.MatchTypePrefix, t.handleStart),
 	}
+	if cfg.ChatID != 0 {
+		// chat_member updates are off by default; subscribe explicitly (alongside
+		// messages) so the bot sees joins in the moderated chat. The bot must also be an
+		// administrator there for Telegram to deliver them.
+		opts = append(opts, tgbot.WithAllowedUpdates(tgbot.AllowedUpdates{
+			models.AllowedUpdateMessage,
+			models.AllowedUpdateMyChatMember,
+			models.AllowedUpdateChatMember,
+		}))
+	}
 	if cfg.TestEnv {
 		// Route to the Bot API test environment (.../bot<token>/test/METHOD).
 		opts = append(opts, tgbot.UseTestEnvironment())
@@ -90,9 +120,39 @@ func (t *Bot) Run(ctx context.Context) {
 	}); err != nil {
 		t.log.Warn("set menu button failed", zap.Error(err))
 	}
+	if t.chatID != 0 {
+		t.logChatAdminStatus(ctx)
+	}
 	t.api.Start(ctx)
 }
 
+// logChatAdminStatus checks, at startup, whether the bot can actually gate the
+// moderated chat — it must be an administrator there with the restrict-members
+// ("Ban users") right, or Telegram delivers no chat_member updates and restricts
+// fail. It logs a prominent warning when the prerequisite is missing (the common
+// misconfiguration), so the cause is visible without reproducing a join.
+func (t *Bot) logChatAdminStatus(ctx context.Context) {
+	me, err := t.api.GetMe(ctx)
+	if err != nil {
+		t.log.Warn("chat self-check: getMe failed", zap.Error(err))
+		return
+	}
+	t.botID = me.ID
+	m, err := t.api.GetChatMember(ctx, &tgbot.GetChatMemberParams{ChatID: t.chatID, UserID: me.ID})
+	if err != nil {
+		t.log.Warn("chat gating self-check failed: the bot cannot read the chat — is it added and is TELEGRAM_CHAT_ID the discussion group id?",
+			zap.Int64("chat_id", t.chatID), zap.Error(err))
+		return
+	}
+	canRestrict := m.Type == models.ChatMemberTypeAdministrator && m.Administrator.CanRestrictMembers
+	if !canRestrict {
+		t.log.Warn(`chat gating WILL NOT WORK: the bot must be an administrator with the restrict-members ("Ban users") right`,
+			zap.Int64("chat_id", t.chatID), zap.String("bot_status", string(m.Type)))
+		return
+	}
+	t.log.Info("chat gating ready: bot is an admin with the restrict-members right", zap.Int64("chat_id", t.chatID))
+}
+
 // Notify sends a notification message with a Mini App launch button that opens the
 // app at startParam (empty opens the lobby).
 func (t *Bot) Notify(ctx context.Context, chatID int64, text, buttonText, startParam string) error {
@@ -131,6 +191,13 @@ func (t *Bot) handleStart(ctx context.Context, api *tgbot.Bot, update *models.Up
 	if update.Message == nil {
 		return
 	}
+	// Reply only in a private chat: the Mini App launch button is an inline web_app
+	// button, which Telegram permits only in private chats — replying to a group message
+	// (the bot is an admin in the moderated chat and now receives its messages) fails with
+	// BUTTON_TYPE_INVALID. In the group the bot only manages permissions, it never chats.
+	if update.Message.Chat.Type != models.ChatTypePrivate {
+		return
+	}
 	startParam := startPayload(update.Message.Text)
 	if _, err := api.SendMessage(ctx, &tgbot.SendMessageParams{
 		ChatID:      update.Message.Chat.ID,
@@ -176,3 +243,190 @@ func startPayload(text string) string {
 	}
 	return strings.TrimSpace(strings.TrimPrefix(text, cmd))
 }
+
+// handleUpdate is the default-handler dispatcher: a chat-member change in the
+// moderated chat drives the write-access gate; anything else is treated as a message
+// and gets the Mini App launch reply.
+func (t *Bot) handleUpdate(ctx context.Context, api *tgbot.Bot, update *models.Update) {
+	if update.ChatMember != nil {
+		t.handleChatMember(ctx, update.ChatMember)
+		return
+	}
+	t.handleStart(ctx, api, update)
+}
+
+// SetEligibilityResolver wires the chat-eligibility resolver after construction (the
+// bot-link client backing it is built after the bot).
+func (t *Bot) SetEligibilityResolver(resolve EligibilityResolver) {
+	t.eligibility = resolve
+}
+
+// handleChatMember keeps a chat member's write access in sync with their eligibility.
+// The chat allows sending by default, so the bot mutes an ineligible member (not
+// registered, or admin-suspended, or chat_muted) and restores an eligible one it had
+// muted; an eligible member that can already send is left untouched. It acts only when
+// the current state differs from the desired one, so it is idempotent and does not
+// re-act on its own change; a resolve failure makes no change.
+func (t *Bot) handleChatMember(ctx context.Context, cm *models.ChatMemberUpdated) {
+	user := chatMemberUser(cm.NewChatMember)
+	var uid int64
+	if user != nil {
+		uid = user.ID
+	}
+	// Log every chat_member update the bot receives: the one place to see whether
+	// Telegram delivers joins, for which chat, the transition, who performed it, and the
+	// new member's send/membership state.
+	canSend, isMember := restrictedSendState(cm.NewChatMember)
+	t.log.Debug("chat_member update",
+		zap.Int64("chat_id", cm.Chat.ID),
+		zap.Int64("configured_chat_id", t.chatID),
+		zap.Int64("user_id", uid),
+		zap.Int64("actor_id", cm.From.ID),
+		zap.String("old_status", string(cm.OldChatMember.Type)),
+		zap.String("new_status", string(cm.NewChatMember.Type)),
+		zap.Bool("new_can_send", canSend),
+		zap.Bool("new_is_member", isMember))
+
+	if t.chatID == 0 || cm.Chat.ID != t.chatID {
+		return
+	}
+	if user == nil || user.IsBot {
+		return
+	}
+	// Loop guard: the bot's own restrict re-fires a chat_member update whose performer is
+	// the bot; skip those so a grant never re-triggers itself.
+	if t.botID != 0 && cm.From.ID == t.botID {
+		return
+	}
+	// The chat allows sending by default and the bot only restricts: Telegram intersects
+	// the chat default with the per-user permission, so a per-user grant cannot exceed a
+	// deny-by-default — the gate must mute the ineligible, not grant the eligible.
+	// Determine whether the user is in the chat and can currently send: a plain member
+	// follows the permissive default; a restricted member can send only with
+	// CanSendMessages, and only while a member.
+	var inChat, currentlyCanSend bool
+	switch cm.NewChatMember.Type {
+	case models.ChatMemberTypeMember:
+		inChat, currentlyCanSend = true, true
+	case models.ChatMemberTypeRestricted:
+		inChat, currentlyCanSend = isMember, canSend
+	default:
+		return // left / kicked / administrator / owner — not a member to gate
+	}
+	if !inChat {
+		return
+	}
+	if t.eligibility == nil {
+		t.log.Warn("chat access: eligibility resolver not wired", zap.Int64("user_id", uid))
+		return
+	}
+	eligible, err := t.eligibility(ctx, strconv.FormatInt(user.ID, 10))
+	if err != nil {
+		t.log.Warn("chat access eligibility failed", zap.Int64("user_id", user.ID), zap.Error(err))
+		return
+	}
+	t.log.Debug("chat access evaluated",
+		zap.Int64("user_id", user.ID), zap.Bool("eligible", eligible), zap.Bool("can_send", currentlyCanSend))
+	// Desired: an eligible user may send, an ineligible one may not. Act only when the
+	// current state differs — idempotent, a no-op for the common eligible member, and it
+	// keeps the bot from re-acting on its own change.
+	if eligible == currentlyCanSend {
+		return
+	}
+	if err := t.setChatWrite(ctx, user.ID, eligible); err != nil {
+		t.log.Warn("set chat write failed",
+			zap.Int64("user_id", user.ID), zap.Bool("can_send", eligible), zap.Error(err))
+		return
+	}
+	t.log.Info("chat access applied", zap.Int64("user_id", user.ID), zap.Bool("can_send", eligible))
+}
+
+// ApplyChatGate applies a chat-gate command (an admin block/unblock or chat_muted
+// change relayed by the gateway): it sets the user's write access, but only when they
+// are currently in the chat. Bots cannot list members, so it probes the single user
+// with getChatMember and is a no-op when they are absent (left/kicked) or an
+// administrator (who cannot be restricted). It reports whether a restriction was
+// applied.
+func (t *Bot) ApplyChatGate(ctx context.Context, userID int64, allow bool) (bool, error) {
+	if t.chatID == 0 {
+		return false, nil
+	}
+	member, err := t.api.GetChatMember(ctx, &tgbot.GetChatMemberParams{ChatID: t.chatID, UserID: userID})
+	if err != nil {
+		return false, err
+	}
+	switch member.Type {
+	case models.ChatMemberTypeMember, models.ChatMemberTypeRestricted:
+		if err := t.setChatWrite(ctx, userID, allow); err != nil {
+			return false, err
+		}
+		t.log.Info("chat gate applied", zap.Int64("user_id", userID), zap.Bool("allow", allow))
+		return true, nil
+	default:
+		t.log.Debug("chat gate: user not in chat, skipped", zap.Int64("user_id", userID), zap.String("status", string(member.Type)))
+		return false, nil // absent, or an admin/owner who cannot be restricted
+	}
+}
+
+// setChatWrite restricts the user in the moderated chat to either the full send
+// permission set (allow) or none (mute); the non-send permissions stay at their
+// default-deny either way.
+func (t *Bot) setChatWrite(ctx context.Context, userID int64, allow bool) error {
+	perms := models.ChatPermissions{}
+	if allow {
+		perms = chatWritePerms()
+	}
+	_, err := t.api.RestrictChatMember(ctx, &tgbot.RestrictChatMemberParams{
+		ChatID:      t.chatID,
+		UserID:      userID,
+		Permissions: &perms,
+	})
+	return err
+}
+
+// chatWritePerms grants a member the ability to send every kind of message; the
+// non-send permissions stay denied.
+func chatWritePerms() models.ChatPermissions {
+	return models.ChatPermissions{
+		CanSendMessages:       true,
+		CanSendAudios:         true,
+		CanSendDocuments:      true,
+		CanSendPhotos:         true,
+		CanSendVideos:         true,
+		CanSendVideoNotes:     true,
+		CanSendVoiceNotes:     true,
+		CanSendPolls:          true,
+		CanSendOtherMessages:  true,
+		CanAddWebPagePreviews: true,
+	}
+}
+
+// restrictedSendState returns a restricted member's text-send permission and whether
+// they are currently a member of the chat; (false, false) for any non-restricted
+// status (the fields exist only on the restricted variant).
+func restrictedSendState(m models.ChatMember) (canSend, isMember bool) {
+	if m.Type == models.ChatMemberTypeRestricted && m.Restricted != nil {
+		return m.Restricted.CanSendMessages, m.Restricted.IsMember
+	}
+	return false, false
+}
+
+// chatMemberUser returns the user a ChatMember refers to across the union variants,
+// or nil for an unrecognised type.
+func chatMemberUser(m models.ChatMember) *models.User {
+	switch m.Type {
+	case models.ChatMemberTypeOwner:
+		return m.Owner.User
+	case models.ChatMemberTypeAdministrator:
+		return &m.Administrator.User
+	case models.ChatMemberTypeMember:
+		return m.Member.User
+	case models.ChatMemberTypeRestricted:
+		return m.Restricted.User
+	case models.ChatMemberTypeLeft:
+		return m.Left.User
+	case models.ChatMemberTypeBanned:
+		return m.Banned.User
+	}
+	return nil
+}

platform/telegram/internal/bot/bot_test.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/go-telegram/bot/models"
 	"go.uber.org/zap"
 )
 
@@ -103,6 +104,29 @@ func TestTestEnvironmentRoutesGetMe(t *testing.T) {
 	}
 }
 
+func TestHandleStartRepliesPrivateOnly(t *testing.T) {
+	t.Run("private replies", func(t *testing.T) {
+		api := &fakeBotAPI{}
+		b := newTestBot(t, api)
+		b.handleStart(context.Background(), b.api, &models.Update{Message: &models.Message{
+			Chat: models.Chat{ID: 42, Type: models.ChatTypePrivate}, Text: "/start g7",
+		}})
+		if api.chatID != "42" || !strings.Contains(api.replyMarkup, "web_app") {
+			t.Errorf("private /start: chat=%q markup=%q, want a web_app reply", api.chatID, api.replyMarkup)
+		}
+	})
+	t.Run("group ignored", func(t *testing.T) {
+		api := &fakeBotAPI{}
+		b := newTestBot(t, api)
+		b.handleStart(context.Background(), b.api, &models.Update{Message: &models.Message{
+			Chat: models.Chat{ID: -100, Type: models.ChatTypeSupergroup}, Text: "/start",
+		}})
+		if api.chatID != "" {
+			t.Errorf("group /start got a reply (chat=%q); an inline web_app button is invalid in groups", api.chatID)
+		}
+	})
+}
+
 func TestStartPayload(t *testing.T) {
 	cases := map[string]string{
 		"/start g123":  "g123",

platform/telegram/internal/bot/chat_test.go

@@ -0,0 +1,239 @@
+package bot
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/go-telegram/bot/models"
+	"go.uber.org/zap"
+)
+
+const (
+	testChatID = 555
+	botSelfID  = 111111 // the bot's own id in tests (for the loop guard)
+)
+
+// chatAPI is a fake Bot API for the chat-gating tests: it answers getMe, returns a
+// scripted getChatMember status, and records restrictChatMember calls.
+type chatAPI struct {
+	memberStatus string // the status getChatMember reports (default "left")
+	restricts    []restrictCall
+}
+
+type restrictCall struct {
+	userID  string
+	canSend bool // can_send_messages in the applied permissions
+}
+
+func (a *chatAPI) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	switch {
+	case strings.HasSuffix(r.URL.Path, "/getMe"):
+		io.WriteString(w, `{"ok":true,"result":{"id":1,"is_bot":true,"first_name":"t","username":"tb"}}`)
+	case strings.HasSuffix(r.URL.Path, "/getChatMember"):
+		status := a.memberStatus
+		if status == "" {
+			status = "left"
+		}
+		io.WriteString(w, `{"ok":true,"result":{"status":"`+status+`","user":{"id":`+r.FormValue("user_id")+`,"is_bot":false,"first_name":"u"}}}`)
+	case strings.HasSuffix(r.URL.Path, "/restrictChatMember"):
+		var perms struct {
+			CanSendMessages bool `json:"can_send_messages"`
+		}
+		_ = json.Unmarshal([]byte(r.FormValue("permissions")), &perms)
+		a.restricts = append(a.restricts, restrictCall{userID: r.FormValue("user_id"), canSend: perms.CanSendMessages})
+		io.WriteString(w, `{"ok":true,"result":true}`)
+	default:
+		io.WriteString(w, `{"ok":true,"result":true}`)
+	}
+}
+
+// newChatBot builds a gating bot (ChatID set) over the fake API, without an
+// eligibility resolver — each test wires the one it needs.
+func newChatBot(t *testing.T, api *chatAPI) *Bot {
+	t.Helper()
+	srv := httptest.NewServer(api)
+	t.Cleanup(srv.Close)
+	b, err := New(Config{Token: "123:ABC", APIBaseURL: srv.URL, MiniAppURL: "https://example.com/", ChatID: testChatID}, zap.NewNop())
+	if err != nil {
+		t.Fatalf("new bot: %v", err)
+	}
+	b.botID = botSelfID // normally set at startup; the chat_member updates default actor 0 != this
+	return b
+}
+
+// memberUpdate builds an oldType -> member transition for userID in chatID.
+func memberUpdate(chatID, userID int64, oldType models.ChatMemberType) *models.ChatMemberUpdated {
+	return &models.ChatMemberUpdated{
+		Chat:          models.Chat{ID: chatID},
+		OldChatMember: models.ChatMember{Type: oldType, Left: &models.ChatMemberLeft{User: &models.User{ID: userID}}},
+		NewChatMember: models.ChatMember{Type: models.ChatMemberTypeMember, Member: &models.ChatMemberMember{User: &models.User{ID: userID}}},
+	}
+}
+
+// restrictedUpdate builds an oldType -> restricted transition for userID, the new
+// member's text-send permission set to canSend and membership to isMember. A muted
+// member is restricted with canSend=false; an un-muted one with canSend=true.
+func restrictedUpdate(chatID, userID int64, oldType models.ChatMemberType, canSend, isMember bool) *models.ChatMemberUpdated {
+	return &models.ChatMemberUpdated{
+		Chat:          models.Chat{ID: chatID},
+		OldChatMember: models.ChatMember{Type: oldType, Left: &models.ChatMemberLeft{User: &models.User{ID: userID}}},
+		NewChatMember: models.ChatMember{Type: models.ChatMemberTypeRestricted, Restricted: &models.ChatMemberRestricted{User: &models.User{ID: userID}, CanSendMessages: canSend, IsMember: isMember}},
+	}
+}
+
+// leftUpdate builds a transition to left (a leave) for userID.
+func leftUpdate(chatID, userID int64) *models.ChatMemberUpdated {
+	return &models.ChatMemberUpdated{
+		Chat:          models.Chat{ID: chatID},
+		OldChatMember: models.ChatMember{Type: models.ChatMemberTypeRestricted, Restricted: &models.ChatMemberRestricted{User: &models.User{ID: userID}}},
+		NewChatMember: models.ChatMember{Type: models.ChatMemberTypeLeft, Left: &models.ChatMemberLeft{User: &models.User{ID: userID}}},
+	}
+}
+
+// eligibleBot builds a gating bot whose resolver returns (eligible, err).
+func eligibleBot(t *testing.T, api *chatAPI, eligible bool, err error) *Bot {
+	t.Helper()
+	b := newChatBot(t, api)
+	b.SetEligibilityResolver(func(context.Context, string) (bool, error) { return eligible, err })
+	return b
+}
+
+func TestHandleChatMemberMutesIneligibleMember(t *testing.T) {
+	// An unregistered/blocked member can send by the permissive default, so the bot mutes.
+	api := &chatAPI{}
+	b := eligibleBot(t, api, false, nil)
+	b.handleChatMember(context.Background(), memberUpdate(testChatID, 777, models.ChatMemberTypeLeft))
+	if len(api.restricts) != 1 || api.restricts[0].userID != "777" || api.restricts[0].canSend {
+		t.Fatalf("restricts = %+v, want one mute (can_send=false) for 777", api.restricts)
+	}
+}
+
+func TestHandleChatMemberLeavesEligibleMemberAlone(t *testing.T) {
+	// An eligible plain member already sends (the permissive default); no action needed.
+	api := &chatAPI{}
+	b := eligibleBot(t, api, true, nil)
+	b.handleChatMember(context.Background(), memberUpdate(testChatID, 777, models.ChatMemberTypeLeft))
+	if len(api.restricts) != 0 {
+		t.Fatalf("restricts = %+v, want none for an eligible member (already allowed)", api.restricts)
+	}
+}
+
+func TestHandleChatMemberUnmutesEligibleRestricted(t *testing.T) {
+	// An eligible member the bot had muted (restricted, can_send=false) is restored.
+	api := &chatAPI{}
+	b := eligibleBot(t, api, true, nil)
+	b.handleChatMember(context.Background(), restrictedUpdate(testChatID, 777, models.ChatMemberTypeRestricted, false, true))
+	if len(api.restricts) != 1 || !api.restricts[0].canSend {
+		t.Fatalf("restricts = %+v, want one un-mute (can_send=true)", api.restricts)
+	}
+}
+
+func TestHandleChatMemberLeavesEligibleAllowedRestrictedAlone(t *testing.T) {
+	// An eligible restricted member who can already send needs no change — the real case
+	// from the contour (restricted, can_send=true, eligible).
+	api := &chatAPI{}
+	b := eligibleBot(t, api, true, nil)
+	b.handleChatMember(context.Background(), restrictedUpdate(testChatID, 777, models.ChatMemberTypeRestricted, true, true))
+	if len(api.restricts) != 0 {
+		t.Fatalf("restricts = %+v, want none for an eligible already-allowed member", api.restricts)
+	}
+}
+
+func TestHandleChatMemberMutesIneligibleRestricted(t *testing.T) {
+	// An ineligible member who can still send is muted.
+	api := &chatAPI{}
+	b := eligibleBot(t, api, false, nil)
+	b.handleChatMember(context.Background(), restrictedUpdate(testChatID, 777, models.ChatMemberTypeRestricted, true, true))
+	if len(api.restricts) != 1 || api.restricts[0].canSend {
+		t.Fatalf("restricts = %+v, want one mute (can_send=false)", api.restricts)
+	}
+}
+
+func TestHandleChatMemberSkipsNonMember(t *testing.T) {
+	// A restricted record for a user no longer in the chat (is_member=false) is not acted on.
+	api := &chatAPI{}
+	b := eligibleBot(t, api, false, nil)
+	b.handleChatMember(context.Background(), restrictedUpdate(testChatID, 777, models.ChatMemberTypeRestricted, true, false))
+	if len(api.restricts) != 0 {
+		t.Fatalf("restricts = %+v, want none for a non-member", api.restricts)
+	}
+}
+
+func TestHandleChatMemberSkipsBotsOwnAction(t *testing.T) {
+	// The bot's own restrict re-fires a chat_member update performed by the bot; skip it
+	// so an action never loops (the resolver here would otherwise mute).
+	api := &chatAPI{}
+	b := eligibleBot(t, api, false, nil)
+	upd := memberUpdate(testChatID, 777, models.ChatMemberTypeLeft)
+	upd.From = models.User{ID: botSelfID}
+	b.handleChatMember(context.Background(), upd)
+	if len(api.restricts) != 0 {
+		t.Fatalf("restricts = %+v, want none for the bot's own action (no loop)", api.restricts)
+	}
+}
+
+func TestHandleChatMemberNoChangeOnResolveError(t *testing.T) {
+	api := &chatAPI{}
+	b := eligibleBot(t, api, false, context.DeadlineExceeded)
+	b.handleChatMember(context.Background(), memberUpdate(testChatID, 777, models.ChatMemberTypeLeft))
+	if len(api.restricts) != 0 {
+		t.Fatalf("a resolve error still changed access: %+v (want no change)", api.restricts)
+	}
+}
+
+func TestHandleChatMemberIgnoresOtherChatAndLeaves(t *testing.T) {
+	api := &chatAPI{}
+	b := eligibleBot(t, api, false, nil) // ineligible — would mute if it acted
+	ctx := context.Background()
+	b.handleChatMember(ctx, memberUpdate(999, 777, models.ChatMemberTypeLeft)) // foreign chat
+	b.handleChatMember(ctx, leftUpdate(testChatID, 777))                       // a leave
+	if len(api.restricts) != 0 {
+		t.Fatalf("restricts = %+v, want none for a foreign chat / a leave", api.restricts)
+	}
+}
+
+func TestApplyChatGatePresentMember(t *testing.T) {
+	for _, tc := range []struct {
+		name  string
+		allow bool
+	}{{"grant", true}, {"mute", false}} {
+		t.Run(tc.name, func(t *testing.T) {
+			api := &chatAPI{memberStatus: "member"}
+			b := newChatBot(t, api)
+			applied, err := b.ApplyChatGate(context.Background(), 777, tc.allow)
+			if err != nil {
+				t.Fatalf("apply: %v", err)
+			}
+			if !applied {
+				t.Fatal("applied = false, want true for a present member")
+			}
+			if len(api.restricts) != 1 || api.restricts[0].canSend != tc.allow {
+				t.Fatalf("restricts = %+v, want one with can_send=%v", api.restricts, tc.allow)
+			}
+		})
+	}
+}
+
+func TestApplyChatGateSkipsAbsentAndAdmin(t *testing.T) {
+	for _, status := range []string{"left", "kicked", "administrator", "creator"} {
+		t.Run(status, func(t *testing.T) {
+			api := &chatAPI{memberStatus: status}
+			b := newChatBot(t, api)
+			applied, err := b.ApplyChatGate(context.Background(), 777, false)
+			if err != nil {
+				t.Fatalf("apply: %v", err)
+			}
+			if applied {
+				t.Errorf("applied = true for status %q, want a no-op", status)
+			}
+			if len(api.restricts) != 0 {
+				t.Errorf("restricts = %+v for status %q, want none", api.restricts, status)
+			}
+		})
+	}
+}

platform/telegram/internal/botlink/client.go

@@ -37,27 +37,25 @@ type ClientConfig struct {
 }
 
 // Client maintains the long-lived bot-link to the gateway, executing the commands
-// it receives and re-dialing after any break.
+// it receives and re-dialing after any break. The same mTLS connection also serves
+// the unary chat-eligibility query the bot makes on a chat join.
 type Client struct {
 	cfg    ClientConfig
 	exec   *Executor
 	log    *zap.Logger
+	conn   *grpc.ClientConn
+	client botlinkv1.BotLinkClient
 }
 
-// NewClient builds the bot-link client over the executor.
-func NewClient(cfg ClientConfig, exec *Executor, log *zap.Logger) *Client {
+// NewClient builds the bot-link client over the executor, dialing the gateway. The
+// gRPC connection is lazy, so the dial does not block on the gateway being up; the
+// caller must Close it. The bot-link command stream is opened by Run.
+func NewClient(cfg ClientConfig, exec *Executor, log *zap.Logger) (*Client, error) {
 	if log == nil {
 		log = zap.NewNop()
 	}
-	return &Client{cfg: cfg, exec: exec, log: log}
-}
-
-// Run dials the gateway and keeps the bot-link open, re-dialing after each break,
-// until ctx is cancelled. The gRPC connection auto-reconnects the transport; this
-// loop re-opens the Link stream on top of it.
-func (c *Client) Run(ctx context.Context) error {
-	conn, err := grpc.NewClient(c.cfg.GatewayAddr,
-		grpc.WithTransportCredentials(c.cfg.Creds),
+	conn, err := grpc.NewClient(cfg.GatewayAddr,
+		grpc.WithTransportCredentials(cfg.Creds),
 		grpc.WithStatsHandler(otelgrpc.NewClientHandler()),
 		grpc.WithKeepaliveParams(keepalive.ClientParameters{
 			Time:                clientKeepaliveTime,
@@ -66,13 +64,30 @@ func (c *Client) Run(ctx context.Context) error {
 		}),
 	)
 	if err != nil {
-		return err
+		return nil, err
 	}
-	defer func() { _ = conn.Close() }()
-	client := botlinkv1.NewBotLinkClient(conn)
+	return &Client{cfg: cfg, exec: exec, log: log, conn: conn, client: botlinkv1.NewBotLinkClient(conn)}, nil
+}
 
+// Close releases the bot-link connection.
+func (c *Client) Close() error { return c.conn.Close() }
+
+// ResolveChatEligibility asks the gateway whether the Telegram user identified by
+// externalID may write in the moderated chat. The bot calls it on a chat join, over
+// the same mTLS connection as the command stream.
+func (c *Client) ResolveChatEligibility(ctx context.Context, externalID string) (bool, error) {
+	resp, err := c.client.ResolveChatEligibility(ctx, &botlinkv1.ChatEligibilityRequest{ExternalId: externalID})
+	if err != nil {
+		return false, err
+	}
+	return resp.GetEligible(), nil
+}
+
+// Run keeps the bot-link command stream open, re-opening it after each break, until
+// ctx is cancelled. The gRPC connection auto-reconnects the transport underneath.
+func (c *Client) Run(ctx context.Context) error {
 	for ctx.Err() == nil {
-		if err := c.serve(ctx, client); err != nil && ctx.Err() == nil {
+		if err := c.serve(ctx, c.client); err != nil && ctx.Err() == nil {
 			c.log.Warn("bot-link stream ended", zap.Error(err))
 		}
 		if !sleep(ctx, c.cfg.ReconnectDelay) {

platform/telegram/internal/botlink/client_test.go

@@ -63,12 +63,16 @@ func TestClientServesCommands(t *testing.T) {
 	t.Cleanup(srv.Stop)
 
 	sender := &fakeSender{}
-	client := NewClient(ClientConfig{
+	client, err := NewClient(ClientConfig{
 		GatewayAddr:    lis.Addr().String(),
 		InstanceID:     "test",
 		Creds:          insecure.NewCredentials(),
 		ReconnectDelay: 50 * time.Millisecond,
 	}, NewExecutor(sender, 0, nil), nil)
+	if err != nil {
+		t.Fatalf("new client: %v", err)
+	}
+	t.Cleanup(func() { _ = client.Close() })
 
 	go func() { _ = client.Run(t.Context()) }()
 

platform/telegram/internal/botlink/executor.go

@@ -23,6 +23,10 @@ type Sender interface {
 	Notify(ctx context.Context, chatID int64, text, buttonText, startParam string) error
 	// SendText sends a plain text message to chatID.
 	SendText(ctx context.Context, chatID int64, text string) error
+	// ApplyChatGate sets the Telegram user's write access in the moderated discussion
+	// chat, but only when they are currently in it; it reports whether a restriction
+	// was applied.
+	ApplyChatGate(ctx context.Context, userID int64, allow bool) (bool, error)
 }
 
 // Executor turns a bot-link Command into a Bot API send. The delivered flag mirrors
@@ -53,11 +57,30 @@ func (e *Executor) Handle(ctx context.Context, cmd *botlinkv1.Command) (bool, er
 		return e.sendToUser(ctx, p.SendToUser)
 	case *botlinkv1.Command_SendToChannel:
 		return e.sendToChannel(ctx, p.SendToChannel)
+	case *botlinkv1.Command_ChatGate:
+		return e.chatGate(ctx, p.ChatGate)
 	default:
 		return false, fmt.Errorf("botlink: empty command")
 	}
 }
 
+// chatGate applies a chat-gate command: it parses the target Telegram user id and
+// sets their write access in the moderated chat (a no-op when they are not in it). A
+// Bot API failure is logged and reported as not-delivered, not a hard error.
+func (e *Executor) chatGate(ctx context.Context, req *botlinkv1.ChatGateCommand) (bool, error) {
+	userID, err := parseChatID(req.GetExternalId())
+	if err != nil {
+		return false, err
+	}
+	applied, err := e.sender.ApplyChatGate(ctx, userID, req.GetAllow())
+	if err != nil {
+		e.log.Warn("chat gate apply failed",
+			zap.String("external_id", req.GetExternalId()), zap.Bool("allow", req.GetAllow()), zap.Error(err))
+		return false, nil
+	}
+	return applied, nil
+}
+
 // notify renders an out-of-app push and sends it with a Mini App launch button.
 func (e *Executor) notify(ctx context.Context, req *telegramv1.NotifyRequest) (bool, error) {
 	msg, ok := render.Render(req.GetKind(), req.GetPayload(), req.GetLanguage())

platform/telegram/internal/botlink/executor_test.go

@@ -15,6 +15,8 @@ import (
 type fakeSender struct {
 	notify  []notifyCall
 	text    []textCall
+	gate    []gateCall
+	applied bool // ApplyChatGate's reported result
 	err     error
 }
 
@@ -26,6 +28,10 @@ type textCall struct {
 	chatID int64
 	text   string
 }
+type gateCall struct {
+	userID int64
+	allow  bool
+}
 
 func (f *fakeSender) Notify(_ context.Context, chatID int64, text, buttonText, startParam string) error {
 	f.notify = append(f.notify, notifyCall{chatID, text, buttonText, startParam})
@@ -37,6 +43,11 @@ func (f *fakeSender) SendText(_ context.Context, chatID int64, text string) erro
 	return f.err
 }
 
+func (f *fakeSender) ApplyChatGate(_ context.Context, userID int64, allow bool) (bool, error) {
+	f.gate = append(f.gate, gateCall{userID, allow})
+	return f.applied, f.err
+}
+
 func yourTurnPayload(gameID string) []byte {
 	b := flatbuffers.NewBuilder(0)
 	gid := b.CreateString(gameID)
@@ -106,6 +117,46 @@ func TestExecutorSendToUser(t *testing.T) {
 	}
 }
 
+func chatGateCmd(externalID string, allow bool) *botlinkv1.Command {
+	return &botlinkv1.Command{Payload: &botlinkv1.Command_ChatGate{ChatGate: &botlinkv1.ChatGateCommand{
+		ExternalId: externalID, Allow: allow,
+	}}}
+}
+
+func TestExecutorChatGateApplied(t *testing.T) {
+	sender := &fakeSender{applied: true}
+	exec := NewExecutor(sender, 0, nil)
+	delivered, err := exec.Handle(context.Background(), chatGateCmd("777", true))
+	if err != nil {
+		t.Fatalf("handle: %v", err)
+	}
+	if !delivered || len(sender.gate) != 1 || sender.gate[0].userID != 777 || !sender.gate[0].allow {
+		t.Errorf("chat gate = %v / calls %+v", delivered, sender.gate)
+	}
+}
+
+func TestExecutorChatGateNotInChat(t *testing.T) {
+	sender := &fakeSender{applied: false} // user not in the chat
+	exec := NewExecutor(sender, 0, nil)
+	delivered, err := exec.Handle(context.Background(), chatGateCmd("888", false))
+	if err != nil {
+		t.Fatalf("handle: %v", err)
+	}
+	if delivered {
+		t.Error("expected delivered=false when the user is not in the chat")
+	}
+	if len(sender.gate) != 1 {
+		t.Errorf("gate calls = %d, want 1", len(sender.gate))
+	}
+}
+
+func TestExecutorChatGateInvalidExternalID(t *testing.T) {
+	exec := NewExecutor(&fakeSender{}, 0, nil)
+	if _, err := exec.Handle(context.Background(), chatGateCmd("not-a-number", true)); err == nil {
+		t.Error("expected an error for a non-numeric external_id")
+	}
+}
+
 func TestExecutorSendToChannel(t *testing.T) {
 	channelCmd := &botlinkv1.Command{Payload: &botlinkv1.Command_SendToChannel{SendToChannel: &telegramv1.SendToGameChannelRequest{Text: "news"}}}
 

platform/telegram/internal/config/config.go

@@ -37,6 +37,24 @@ type BotConfig struct {
 	// GameChannelID is the chat id of the bot's game channel for the admin channel
 	// post (TELEGRAM_GAME_CHANNEL_ID, optional; 0 disables channel posts).
 	GameChannelID int64
+	// ChatID is the chat id of the moderated discussion supergroup (a channel's linked
+	// chat) whose write access the bot gates by registration and moderation
+	// (TELEGRAM_CHAT_ID, optional; 0 disables chat gating). The bot must be an admin
+	// there with the "Ban users" right, and "chat_member" in its allowed updates.
+	ChatID int64
+	// PromoBotToken is the API token of the optional standalone promo bot run in this
+	// container — a second bot whose only job is to answer /start with a button that
+	// opens the main bot's Mini App (TELEGRAM_PROMO_BOT_TOKEN, optional; empty disables
+	// the promo bot).
+	PromoBotToken string
+	// BotUsername is the main bot's @username without the leading @, used in the promo
+	// bot's message text (TELEGRAM_BOT_USERNAME; required when the promo bot runs).
+	BotUsername string
+	// BotLinkURL is the main bot's Mini App direct link — the same value the UI builds
+	// share links from (VITE_TELEGRAM_LINK), e.g. https://t.me/<bot>/<app>. The promo
+	// button appends ?startapp=<payload> to it (TELEGRAM_BOT_LINK; required when the
+	// promo bot runs). It is distinct from the BotLink mTLS dial config below.
+	BotLinkURL string
 	// MiniAppURL is the HTTPS origin of the Mini App registered with BotFather; it is
 	// the base of every launch button (TELEGRAM_MINIAPP_URL, required).
 	MiniAppURL string
@@ -114,6 +132,9 @@ func LoadBot() (BotConfig, error) {
 		TestEnv:           os.Getenv("TELEGRAM_TEST_ENV") == "true",
 		OwnsUpdates:       os.Getenv("TELEGRAM_OWNS_UPDATES") != "false",
 		SendRatePerSecond: defaultSendRatePerSecond,
+		PromoBotToken:     os.Getenv("TELEGRAM_PROMO_BOT_TOKEN"),
+		BotUsername:       strings.TrimPrefix(os.Getenv("TELEGRAM_BOT_USERNAME"), "@"),
+		BotLinkURL:        os.Getenv("TELEGRAM_BOT_LINK"),
 		LogLevel:          envOr("TELEGRAM_LOG_LEVEL", "info"),
 		BotLink: BotLinkClientConfig{
 			GatewayAddr: os.Getenv("TELEGRAM_GATEWAY_ADDR"),
@@ -128,6 +149,9 @@ func LoadBot() (BotConfig, error) {
 	if cfg.GameChannelID, err = envInt64("TELEGRAM_GAME_CHANNEL_ID", 0); err != nil {
 		return BotConfig{}, err
 	}
+	if cfg.ChatID, err = envInt64("TELEGRAM_CHAT_ID", 0); err != nil {
+		return BotConfig{}, err
+	}
 	if cfg.SendRatePerSecond, err = envInt("TELEGRAM_SEND_RATE_PER_SECOND", defaultSendRatePerSecond); err != nil {
 		return BotConfig{}, err
 	}
@@ -155,6 +179,9 @@ func LoadBot() (BotConfig, error) {
 	if cfg.BotLink.CertFile == "" || cfg.BotLink.KeyFile == "" || cfg.BotLink.CAFile == "" {
 		return BotConfig{}, fmt.Errorf("config: TELEGRAM_BOTLINK_TLS_CERT, _KEY and _CA are required")
 	}
+	if cfg.PromoBotToken != "" && (cfg.BotUsername == "" || cfg.BotLinkURL == "") {
+		return BotConfig{}, fmt.Errorf("config: TELEGRAM_BOT_USERNAME and TELEGRAM_BOT_LINK are required when TELEGRAM_PROMO_BOT_TOKEN is set")
+	}
 	return cfg, nil
 }
 

platform/telegram/internal/config/config_test.go

@@ -103,6 +103,54 @@ func TestLoadBotRequired(t *testing.T) {
 	}
 }
 
+// TestLoadBotChatAndPromo verifies the moderated-chat id and the promo-bot
+// configuration parse, the @-prefix is stripped from the username, and a promo token
+// without a username/link is rejected.
+func TestLoadBotChatAndPromo(t *testing.T) {
+	t.Run("parsed", func(t *testing.T) {
+		setBotRequired(t)
+		t.Setenv("TELEGRAM_CHAT_ID", "-100222")
+		t.Setenv("TELEGRAM_PROMO_BOT_TOKEN", "promo-token")
+		t.Setenv("TELEGRAM_BOT_USERNAME", "@ScrabbleBot")
+		t.Setenv("TELEGRAM_BOT_LINK", "https://t.me/ScrabbleBot/app")
+		c, err := LoadBot()
+		if err != nil {
+			t.Fatalf("LoadBot: %v", err)
+		}
+		if c.ChatID != -100222 {
+			t.Errorf("ChatID = %d, want -100222", c.ChatID)
+		}
+		if c.PromoBotToken != "promo-token" {
+			t.Errorf("PromoBotToken = %q", c.PromoBotToken)
+		}
+		if c.BotUsername != "ScrabbleBot" {
+			t.Errorf("BotUsername = %q, want the leading @ stripped", c.BotUsername)
+		}
+		if c.BotLinkURL != "https://t.me/ScrabbleBot/app" {
+			t.Errorf("BotLinkURL = %q", c.BotLinkURL)
+		}
+	})
+
+	t.Run("promo token requires username and link", func(t *testing.T) {
+		setBotRequired(t)
+		t.Setenv("TELEGRAM_PROMO_BOT_TOKEN", "promo-token")
+		if _, err := LoadBot(); err == nil {
+			t.Fatal("LoadBot: expected an error for a promo token without username/link")
+		}
+	})
+
+	t.Run("disabled by default", func(t *testing.T) {
+		setBotRequired(t)
+		c, err := LoadBot()
+		if err != nil {
+			t.Fatalf("LoadBot: %v", err)
+		}
+		if c.PromoBotToken != "" || c.ChatID != 0 {
+			t.Errorf("defaults: promo=%q chat=%d, want empty/0", c.PromoBotToken, c.ChatID)
+		}
+	})
+}
+
 // TestLoadRejectsUnsupportedExporter verifies an exporter outside the supported set
 // fails validation (the validator path).
 func TestLoadRejectsUnsupportedExporter(t *testing.T) {

platform/telegram/internal/promobot/promobot.go

@@ -0,0 +1,169 @@
+// Package promobot is the standalone promo bot: a second Telegram bot in the bot
+// container whose only job is to answer /start with a localized message and a button
+// that opens the MAIN bot's Mini App. It is self-contained — it never calls the
+// gateway or the game — so onboarding works even when the game is down. The button is
+// a URL to the main bot's direct Mini App link: a web_app button would launch the Mini
+// App under the promo bot's identity (its token would sign the initData), which the
+// main bot's validator would reject, so the cross-bot launch must be a t.me link. It
+// reuses the same link the UI builds invitation links from (VITE_TELEGRAM_LINK).
+package promobot
+
+import (
+	"context"
+	"net/url"
+	"strings"
+
+	tgbot "github.com/go-telegram/bot"
+	"github.com/go-telegram/bot/models"
+	"go.uber.org/zap"
+	"golang.org/x/time/rate"
+)
+
+// Config configures the promo bot.
+type Config struct {
+	// Token is the promo bot's Bot API token.
+	Token string
+	// APIBaseURL overrides the Bot API host ("" uses https://api.telegram.org).
+	APIBaseURL string
+	// TestEnv routes requests to the Bot API test environment.
+	TestEnv bool
+	// BotUsername is the main bot's @username without the leading @, named in the
+	// message text.
+	BotUsername string
+	// BotLinkURL is the main bot's Mini App direct link; the button appends
+	// ?startapp=<payload> to it.
+	BotLinkURL string
+	// SendRatePerSecond caps outbound sends to respect the Bot API flood limits; 0
+	// disables the limiter. The burst equals the per-second rate.
+	SendRatePerSecond int
+}
+
+// Bot is the promo bot wrapper around a Telegram Bot API client.
+type Bot struct {
+	api      *tgbot.Bot
+	username string
+	linkURL  string
+	log      *zap.Logger
+	limiter  *rate.Limiter
+}
+
+// New builds the promo bot, registering a /start (and default) handler that replies
+// with the launch button. It does not start polling; call Run for that.
+func New(cfg Config, log *zap.Logger) (*Bot, error) {
+	if log == nil {
+		log = zap.NewNop()
+	}
+	t := &Bot{username: cfg.BotUsername, linkURL: cfg.BotLinkURL, log: log}
+	if cfg.SendRatePerSecond > 0 {
+		t.limiter = rate.NewLimiter(rate.Limit(cfg.SendRatePerSecond), cfg.SendRatePerSecond)
+	}
+	opts := []tgbot.Option{
+		tgbot.WithDefaultHandler(t.handleStart),
+		tgbot.WithMessageTextHandler("/start", tgbot.MatchTypePrefix, t.handleStart),
+	}
+	if cfg.TestEnv {
+		opts = append(opts, tgbot.UseTestEnvironment())
+	}
+	if cfg.APIBaseURL != "" {
+		opts = append(opts, tgbot.WithServerURL(cfg.APIBaseURL))
+	}
+	api, err := tgbot.New(cfg.Token, opts...)
+	if err != nil {
+		return nil, err
+	}
+	t.api = api
+	return t, nil
+}
+
+// Run sets the bot command, then blocks on the long-poll update loop until ctx is
+// cancelled.
+func (t *Bot) Run(ctx context.Context) {
+	if _, err := t.api.SetMyCommands(ctx, &tgbot.SetMyCommandsParams{
+		Commands: []models.BotCommand{{Command: "start", Description: "Open Scrabble"}},
+	}); err != nil {
+		t.log.Warn("promo: set commands failed", zap.Error(err))
+	}
+	t.api.Start(ctx)
+}
+
+// handleStart replies to any message (typically /start) with the localized promo text
+// and a button that opens the main bot's Mini App, forwarding any /start payload.
+func (t *Bot) handleStart(ctx context.Context, api *tgbot.Bot, update *models.Update) {
+	if update.Message == nil {
+		return
+	}
+	// Only respond to a private /start: the promo bot is a one-on-one onboarding entry
+	// point and should never reply to group messages.
+	if update.Message.Chat.Type != models.ChatTypePrivate {
+		return
+	}
+	if err := t.throttle(ctx); err != nil {
+		return
+	}
+	lang := ""
+	if update.Message.From != nil {
+		lang = update.Message.From.LanguageCode
+	}
+	text, button := promoText(lang, t.username)
+	if _, err := api.SendMessage(ctx, &tgbot.SendMessageParams{
+		ChatID:      update.Message.Chat.ID,
+		Text:        text,
+		ReplyMarkup: t.launchMarkup(button, startPayload(update.Message.Text)),
+	}); err != nil {
+		t.log.Warn("promo: reply to start failed", zap.Error(err))
+	}
+}
+
+// launchMarkup builds the single URL button that opens the main bot's Mini App at the
+// optional startapp payload.
+func (t *Bot) launchMarkup(buttonText, startParam string) *models.InlineKeyboardMarkup {
+	return &models.InlineKeyboardMarkup{
+		InlineKeyboard: [][]models.InlineKeyboardButton{{
+			{Text: buttonText, URL: t.launchURL(startParam)},
+		}},
+	}
+}
+
+// launchURL appends the startapp payload to the main bot's Mini App link; an empty
+// payload returns the base link unchanged.
+func (t *Bot) launchURL(startParam string) string {
+	if startParam == "" {
+		return t.linkURL
+	}
+	u, err := url.Parse(t.linkURL)
+	if err != nil {
+		return t.linkURL
+	}
+	q := u.Query()
+	q.Set("startapp", startParam)
+	u.RawQuery = q.Encode()
+	return u.String()
+}
+
+// throttle blocks until the rate limiter admits one send, or ctx is cancelled. It is
+// a no-op when no limiter is configured.
+func (t *Bot) throttle(ctx context.Context) error {
+	if t.limiter == nil {
+		return nil
+	}
+	return t.limiter.Wait(ctx)
+}
+
+// startPayload extracts the deep-link payload from a "/start <payload>" command; any
+// other text yields an empty payload (open the lobby).
+func startPayload(text string) string {
+	const cmd = "/start"
+	if !strings.HasPrefix(text, cmd) {
+		return ""
+	}
+	return strings.TrimSpace(strings.TrimPrefix(text, cmd))
+}
+
+// promoText returns the localized message body and button label, naming the main bot
+// (Russian for a "ru" language code, English otherwise).
+func promoText(lang, username string) (text, button string) {
+	if strings.HasPrefix(strings.ToLower(lang), "ru") {
+		return "Откройте @" + username + " и выберите в настройках профиля нужный вариант игры.", "🤩 Хочу играть!"
+	}
+	return "Open @" + username + " and choose your game variant in the profile settings.", "🤩 I want to play!"
+}

platform/telegram/internal/promobot/promobot_test.go

@@ -0,0 +1,121 @@
+package promobot
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/go-telegram/bot/models"
+	"go.uber.org/zap"
+)
+
+func TestPromoTextLocalization(t *testing.T) {
+	en, enBtn := promoText("en", "ScrabbleBot")
+	if !strings.Contains(en, "@ScrabbleBot") || !strings.Contains(en, "profile settings") {
+		t.Errorf("en text = %q", en)
+	}
+	if enBtn != "🤩 I want to play!" {
+		t.Errorf("en button = %q", enBtn)
+	}
+
+	ru, ruBtn := promoText("ru-RU", "ScrabbleBot")
+	if !strings.Contains(ru, "@ScrabbleBot") || !strings.Contains(ru, "Откройте") {
+		t.Errorf("ru text = %q", ru)
+	}
+	if ruBtn != "🤩 Хочу играть!" {
+		t.Errorf("ru button = %q", ruBtn)
+	}
+
+	// An unknown language falls back to English.
+	if got, _ := promoText("de", "B"); !strings.Contains(got, "Open @B") {
+		t.Errorf("fallback text = %q, want English", got)
+	}
+}
+
+func TestLaunchURLAppendsStartapp(t *testing.T) {
+	b := &Bot{linkURL: "https://t.me/bot/app"}
+	if got := b.launchURL(""); got != "https://t.me/bot/app" {
+		t.Errorf("empty payload = %q, want the base link unchanged", got)
+	}
+	if got := b.launchURL("g123"); got != "https://t.me/bot/app?startapp=g123" {
+		t.Errorf("launchURL = %q, want startapp=g123 appended", got)
+	}
+}
+
+func TestLaunchMarkupIsURLButton(t *testing.T) {
+	b := &Bot{linkURL: "https://t.me/bot/app"}
+	btn := b.launchMarkup("Play", "f99").InlineKeyboard[0][0]
+	if btn.WebApp != nil {
+		t.Error("the promo button must not be a web_app button (it would sign initData with the promo token, which the main bot rejects)")
+	}
+	if !strings.Contains(btn.URL, "startapp=f99") {
+		t.Errorf("button URL = %q, want startapp=f99", btn.URL)
+	}
+}
+
+// fakeAPI answers getMe (so New succeeds offline) and records the last sendMessage.
+type fakeAPI struct {
+	chatID, text, replyMarkup string
+}
+
+func (f *fakeAPI) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	switch {
+	case strings.HasSuffix(r.URL.Path, "/getMe"):
+		io.WriteString(w, `{"ok":true,"result":{"id":1,"is_bot":true,"first_name":"t","username":"promo"}}`)
+	case strings.HasSuffix(r.URL.Path, "/sendMessage"):
+		f.chatID = r.FormValue("chat_id")
+		f.text = r.FormValue("text")
+		f.replyMarkup = r.FormValue("reply_markup")
+		io.WriteString(w, `{"ok":true,"result":{"message_id":1}}`)
+	default:
+		io.WriteString(w, `{"ok":true,"result":true}`)
+	}
+}
+
+func TestHandleStartReplies(t *testing.T) {
+	api := &fakeAPI{}
+	srv := httptest.NewServer(api)
+	t.Cleanup(srv.Close)
+	b, err := New(Config{Token: "1:2", APIBaseURL: srv.URL, BotUsername: "ScrabbleBot", BotLinkURL: "https://t.me/bot/app"}, zap.NewNop())
+	if err != nil {
+		t.Fatalf("new: %v", err)
+	}
+
+	b.handleStart(context.Background(), b.api, &models.Update{Message: &models.Message{
+		Chat: models.Chat{ID: 42, Type: models.ChatTypePrivate},
+		From: &models.User{LanguageCode: "ru"},
+		Text: "/start f99",
+	}})
+
+	if api.chatID != "42" {
+		t.Errorf("chat_id = %q, want 42", api.chatID)
+	}
+	if !strings.Contains(api.text, "@ScrabbleBot") {
+		t.Errorf("text = %q, want the @mention", api.text)
+	}
+	if strings.Contains(api.replyMarkup, "web_app") {
+		t.Errorf("reply_markup = %q has a web_app button; want a url button", api.replyMarkup)
+	}
+	if !strings.Contains(api.replyMarkup, "startapp=f99") {
+		t.Errorf("reply_markup = %q, want startapp=f99 (the /start payload forwarded)", api.replyMarkup)
+	}
+}
+
+func TestHandleStartIgnoresGroup(t *testing.T) {
+	api := &fakeAPI{}
+	srv := httptest.NewServer(api)
+	t.Cleanup(srv.Close)
+	b, err := New(Config{Token: "1:2", APIBaseURL: srv.URL, BotUsername: "B", BotLinkURL: "https://t.me/b/a"}, zap.NewNop())
+	if err != nil {
+		t.Fatalf("new: %v", err)
+	}
+	b.handleStart(context.Background(), b.api, &models.Update{Message: &models.Message{
+		Chat: models.Chat{ID: -100, Type: models.ChatTypeSupergroup}, Text: "/start",
+	}})
+	if api.chatID != "" {
+		t.Errorf("replied to a group message (chat=%q); want none", api.chatID)
+	}
+}

ui/e2e/quickmatch.spec.ts

@@ -19,7 +19,7 @@ test('quick game: enter immediately, wait for an opponent, then it joins', async
 
   // Still waiting for an opponent: the opponent card shows the placeholder, and resign (in the
   // history panel) is disabled.
-  await expect(page.getByText(/Searching for opponent/)).toBeVisible();
+  await expect(page.getByText(/Waiting for opponent/)).toBeVisible();
   await page.locator('.scoreboard').click(); // open the history panel
   await expect(page.getByRole('button', { name: 'Drop game' })).toBeDisabled();
 
@@ -28,7 +28,7 @@ test('quick game: enter immediately, wait for an opponent, then it joins', async
 
   // The opponent card shows its name, the placeholder is gone, and resign is enabled again.
   await expect(page.getByText('Robo')).toBeVisible();
-  await expect(page.getByText(/Searching for opponent/)).toHaveCount(0);
+  await expect(page.getByText(/Waiting for opponent/)).toHaveCount(0);
   await expect(page.getByRole('button', { name: 'Drop game' })).toBeEnabled();
 });
 
@@ -48,7 +48,7 @@ test('AI game: 🤖 opponent, no wait, chat disabled, dictionary still works', a
   // The player lands in an active game at once (no "searching" wait); the opponent shows as 🤖.
   await expect(page.locator('[data-cell]').first()).toBeVisible();
   await expect(page.locator('.scoreboard').getByText('🤖')).toBeVisible();
-  await expect(page.getByText(/Searching for opponent/)).toHaveCount(0);
+  await expect(page.getByText(/Waiting for opponent/)).toHaveCount(0);
 
   // An AI game has no chat at all: the comms hub drops the Chat tab and lands on the Dictionary
   // alone, which stays usable.
@@ -96,7 +96,7 @@ async function enterOpenGame(page: import('@playwright/test').Page): Promise<voi
   await page.getByRole('button', { name: 'Random player' }).click();
   await page.locator('.variant').first().click();
   await page.getByRole('button', { name: /Start game/i }).click();
-  await expect(page.getByText(/Searching for opponent/)).toBeVisible();
+  await expect(page.getByText(/Waiting for opponent/)).toBeVisible();
 }
 
 test('quick game: a poll recovers a join missed while the live stream is down', async ({ page }) => {
@@ -106,7 +106,7 @@ test('quick game: a poll recovers a join missed while the live stream is down',
   await page.evaluate(() => (window as unknown as { __stream: { drop(): void } }).__stream.drop());
   await page.evaluate(() => (window as unknown as { __mock: { joinOpponent(): void } }).__mock.joinOpponent());
   await expect(page.getByText('Robo')).toBeVisible();
-  await expect(page.getByText(/Searching for opponent/)).toHaveCount(0);
+  await expect(page.getByText(/Waiting for opponent/)).toHaveCount(0);
 });
 
 test('quick game: a stream reconnect recovers a join missed while it was down', async ({ page }) => {
@@ -117,7 +117,7 @@ test('quick game: a stream reconnect recovers a join missed while it was down',
   await page.evaluate(() => (window as unknown as { __mock: { joinOpponent(): void } }).__mock.joinOpponent());
   await page.evaluate(() => (window as unknown as { __stream: { restore(): void } }).__stream.restore());
   await expect(page.getByText('Robo')).toBeVisible();
-  await expect(page.getByText(/Searching for opponent/)).toHaveCount(0);
+  await expect(page.getByText(/Waiting for opponent/)).toHaveCount(0);
 });
 
 test('quick game: a foreground resync recovers a join shed while the stream stayed alive', async ({ page }) => {
@@ -125,11 +125,11 @@ test('quick game: a foreground resync recovers a join shed while the stream stay
   // The opponent joins but the event is shed with the stream still alive (no reconnect, and the
   // poll only runs while the stream is down): nothing has recovered yet.
   await page.evaluate(() => (window as unknown as { __mock: { joinOpponentSilently(): void } }).__mock.joinOpponentSilently());
-  await expect(page.getByText(/Searching for opponent/)).toBeVisible();
+  await expect(page.getByText(/Waiting for opponent/)).toBeVisible();
   // Returning to the foreground resyncs the open game (pageshow drives goForeground).
   await page.evaluate(() => window.dispatchEvent(new Event('pageshow')));
   await expect(page.getByText('Robo')).toBeVisible();
-  await expect(page.getByText(/Searching for opponent/)).toHaveCount(0);
+  await expect(page.getByText(/Waiting for opponent/)).toHaveCount(0);
 });
 
 // Regression: an opponent joining must not freeze the screen. The in-game live-event effect tracked

ui/e2e/social.spec.ts

@@ -238,7 +238,10 @@ test('profile edit disables Save and flags an invalid display name', async ({ pa
   await expect(save).toBeEnabled();
 });
 
-test('link account: a taken email opens the irreversible merge confirmation', async ({ page }) => {
+// Account linking is hidden in Profile.svelte while we target provider sign-in (the anonymous
+// /app/ guest who upgrades by linking comes later). The flow is kept wired; re-enable these two
+// specs together with the `.emailbox` section.
+test.skip('link account: a taken email opens the irreversible merge confirmation', async ({ page }) => {
   await loginLobby(page);
   await openProfile(page);
 
@@ -258,7 +261,7 @@ test('link account: a taken email opens the irreversible merge confirmation', as
   await expect(page.getByText('Merge accounts?')).toBeHidden();
 });
 
-test('link account: the Telegram web sign-in control is offered in a browser', async ({ page }) => {
+test.skip('link account: the Telegram web sign-in control is offered in a browser', async ({ page }) => {
   await loginLobby(page);
   await openProfile(page);
   await expect(page.getByRole('button', { name: 'Link Telegram' })).toBeVisible();

ui/e2e/telegram.spec.ts

@@ -83,6 +83,30 @@ test('tg-fullscreen header keeps a constant native-nav gap as the font scales',
   expect(large.overflows).toBe(false);
 });
 
+test('inside Telegram, a failed launch shows the retry screen, not the web login', async ({ page }) => {
+  // initData carrying the mock's "bootfail" sentinel makes authTelegram reject, simulating a
+  // backend outage during launch (e.g. a deploy rolling). The Mini App must surface its own
+  // boot-error/retry screen and never fall back to the web (guest/email) login.
+  await page.addInitScript(() => {
+    Object.assign(window, {
+      Telegram: {
+        WebApp: {
+          initData: 'query_id=bootfail&user=%7B%22id%22%3A1%7D&auth_date=1&hash=deadbeef',
+          initDataUnsafe: {},
+          ready() {},
+          expand() {},
+        },
+      },
+    });
+  });
+  await page.goto('/');
+
+  // After the silent retries, the boot-error screen with its Retry button shows…
+  await expect(page.getByRole('button', { name: 'Retry' })).toBeVisible();
+  // …and the web login (guest) is never shown inside Telegram.
+  await expect(page.getByRole('button', { name: /guest/i })).toHaveCount(0);
+});
+
 test('outside Telegram, the /telegram/ entry redirects to the site root', async ({ page }) => {
   await page.goto('/telegram/');
 

ui/src/App.svelte

@@ -18,6 +18,7 @@
   import CommsHub from './game/CommsHub.svelte';
   import Feedback from './screens/Feedback.svelte';
   import Blocked from './screens/Blocked.svelte';
+  import BootError from './screens/BootError.svelte';
 
   onMount(() => {
     void bootstrap();
@@ -83,6 +84,10 @@
   {#if !routeIsLobby}
     <div class="splash">{t('common.loading')}</div>
   {/if}
+{:else if app.bootError}
+  <!-- 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.blocked}
   <Blocked />
 {:else}
@@ -123,7 +128,7 @@
 <StaleInviteModal />
 <WelcomeRedeemModal />
 
-{#if routeIsLobby && !app.splashDone && !app.blocked}
+{#if routeIsLobby && !app.splashDone && !app.blocked && !app.bootError}
   <Splash />
 {/if}
 

ui/src/lib/app.svelte.ts

@@ -18,6 +18,7 @@ import {
   telegramDisableVerticalSwipes,
   telegramHaptic,
   telegramLaunch,
+  type TelegramLaunch,
   telegramOnEvent,
   telegramRequestFullscreen,
   telegramSetChrome,
@@ -41,6 +42,10 @@ export interface Toast {
 
 export const app = $state<{
   ready: boolean;
+  /** Inside a Mini App, set when the launch failed to authenticate after its retries (e.g. the
+   *  backend was down during a deploy). App.svelte then renders the boot-error retry screen
+   *  instead of the web login — a Mini App has no manual sign-in to fall back to. */
+  bootError: boolean;
   /** Whether the lobby's first cold load has settled (success or error). The loading splash
    *  (components/Splash.svelte) watches it to know when to dismiss; set by screens/Lobby. */
   lobbyReady: boolean;
@@ -90,6 +95,7 @@ export const app = $state<{
   resync: number;
 }>({
   ready: false,
+  bootError: false,
   lobbyReady: false,
   splashDone: false,
   streamAlive: false,
@@ -563,14 +569,7 @@ export async function bootstrap(): Promise<void> {
     // listener above then re-syncs the safe-area insets. Desktop keeps the bot's full-size
     // window. No-op on clients predating Bot API 8.0.
     telegramRequestFullscreen();
-    try {
-      await adoptSession(await gateway.authTelegram(launch.initData));
-      // A blocked account skips deep-link routing — the blocked screen overlays every route.
-      if (!app.blocked) await routeStartParam(launch.startParam);
-    } catch (err) {
-      handleError(err);
-      navigate('/login');
-    }
+    await bootTelegram(launch);
     app.ready = true;
     return;
   }
@@ -585,6 +584,57 @@ export async function bootstrap(): Promise<void> {
   app.ready = true;
 }
 
+// Inside a Mini App the only identity is the Telegram session, so a failed launch must never fall
+// back to the web login screen. A transient backend outage (a deploy rolling over) is retried a
+// few times in silence; only then does the boot-error screen surface, from which Retry re-runs the
+// same path (retryTelegramBoot).
+const TELEGRAM_BOOT_RETRIES = 2;
+const TELEGRAM_BOOT_RETRY_MS = 1200;
+
+function delay(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+/**
+ * bootTelegram authenticates a Mini App launch from its initData and routes any deep-link start
+ * parameter, retrying a few times on a transient failure before raising the boot-error screen
+ * (app.bootError). A blocked account is terminal — it switches straight to the blocked screen
+ * without retrying.
+ */
+async function bootTelegram(launch: TelegramLaunch): Promise<void> {
+  for (let attempt = 0; ; attempt++) {
+    try {
+      await adoptSession(await gateway.authTelegram(launch.initData));
+      // A blocked account skips deep-link routing — the blocked screen overlays every route.
+      if (!app.blocked) await routeStartParam(launch.startParam);
+      app.bootError = false;
+      return;
+    } catch (err) {
+      if (err instanceof GatewayError && err.code === 'account_blocked') {
+        await enterBlocked();
+        return;
+      }
+      if (attempt >= TELEGRAM_BOOT_RETRIES) {
+        app.bootError = true;
+        return;
+      }
+      await delay(TELEGRAM_BOOT_RETRY_MS);
+    }
+  }
+}
+
+/**
+ * retryTelegramBoot re-attempts the Mini App launch from the boot-error screen's Retry button. It
+ * clears the error and shows the loading state again, then runs the same retrying boot; on success
+ * the app renders normally, otherwise the boot-error screen returns.
+ */
+export async function retryTelegramBoot(): Promise<void> {
+  app.bootError = false;
+  app.ready = false;
+  await bootTelegram(telegramLaunch());
+  app.ready = true;
+}
+
 /**
  * routeStartParam navigates a Telegram deep-link start parameter to its target: a
  * specific game, the friends screen with a friend-code redemption, or the lobby

ui/src/lib/i18n/en.ts

@@ -11,6 +11,9 @@ export const en = {
   'blocked.temporary': 'Your account is blocked until {until}.',
   'blocked.reason': 'Reason:',
 
+  'boot.errorTitle': "Couldn't load the game",
+  'boot.errorBody': 'Please try again in a moment.',
+
   'common.back': 'Back',
   'common.cancel': 'Cancel',
   'common.ok': 'OK',
@@ -63,7 +66,7 @@ export const en = {
   'game.yourTurn': 'Your turn',
   'game.yourTurnBy': '{name}: Your turn!',
   'game.opponentsTurn': "Opponent's turn",
-  'game.searchingForOpponent': 'Searching for opponent…',
+  'game.searchingForOpponent': 'Waiting for opponent…',
   'game.waiting': "Waiting for {name}",
   'game.makeMove': 'Make move',
   'game.reset': 'Reset',

ui/src/lib/i18n/ru.ts

@@ -12,6 +12,9 @@ export const ru: Record<MessageKey, string> = {
   'blocked.temporary': 'Ваша учётная запись заблокирована до {until}.',
   'blocked.reason': 'Причина:',
 
+  'boot.errorTitle': 'Не удалось загрузить игру',
+  'boot.errorBody': 'Попробуйте ещё раз или зайдите позже.',
+
   'common.back': 'Назад',
   'common.cancel': 'Отмена',
   'common.ok': 'ОК',
@@ -64,7 +67,7 @@ export const ru: Record<MessageKey, string> = {
   'game.yourTurn': 'Ваш ход',
   'game.yourTurnBy': '{name}: Ваш ход!',
   'game.opponentsTurn': 'Ход соперника',
-  'game.searchingForOpponent': 'Поиск соперника...',
+  'game.searchingForOpponent': 'Ждём соперника…',
   'game.waiting': 'Ожидаем {name}',
   'game.makeMove': 'Сделать ход',
   'game.reset': 'Сброс',

ui/src/lib/mock/client.ts

@@ -136,7 +136,10 @@ export class MockGateway implements GatewayClient {
   }
 
   // --- auth ---
-  async authTelegram(): Promise<Session> {
+  async authTelegram(initData: string): Promise<Session> {
+    // e2e hook: an initData carrying this sentinel simulates a backend that rejects the launch,
+    // so the Mini App boot-failure path (silent retries → boot-error screen) can be exercised.
+    if (initData.includes('bootfail')) throw new GatewayError('unavailable');
     return { ...SESSION, isGuest: false };
   }
   async authGuest(): Promise<Session> {