Overhaul deployment to Gitea Actions CI/CD, remove update.sh

Production no longer builds from source or self-updates via cron/git pull:
setup.sh now only provisions the server once (Docker, /opt/anouma, a
restricted `anouma-deploy` SSH user whose key can only ever run
deploy.sh, generated secrets). All future deployments run through
.gitea/workflows/ci.yml (lint/typecheck/test/build on every push) and
release.yml (on a vX.Y.Z tag: build the image, push it to the Gitea
registry, then SSH-trigger deploy.sh on the server), which pulls,
migrates, restarts, healthchecks, backs up the database first, and
automatically rolls back the code on a failed healthcheck.

docker-compose.yml's app service now runs a registry image
(${ANOUMA_IMAGE}) instead of building locally.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitea/workflows/release.yml

@@ -0,0 +1,99 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    container:
+      image: node:22-alpine
+    env:
+      NODE_ENV: production
+      NEXT_TELEMETRY_DISABLED: "1"
+      DATABASE_URI: postgresql://ci:ci@localhost:5432/ci
+      PAYLOAD_SECRET: ci-only-not-a-real-secret
+      MEETING_SESSION_SECRET: ci-only-not-a-real-secret
+      CRON_SECRET: ci-only-not-a-real-secret
+      NEXT_PUBLIC_SERVER_URL: http://localhost:3000
+    steps:
+      - uses: actions/checkout@v4
+      - run: apk add --no-cache libc6-compat
+      - run: npm ci
+      - run: npm run lint
+      - run: npx tsc --noEmit
+      - run: npm test
+      - run: npm run build
+
+  build-and-deploy:
+    needs: test
+    runs-on: ubuntu-latest
+    # No container here — this job needs the Docker CLI + an SSH client
+    # directly on the runner host, not inside a Node container.
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Determine image tags
+        id: image
+        # Gitea Actions' runner is protocol-compatible with GitHub Actions,
+        # so step commands use the same $GITHUB_OUTPUT / $GITHUB_ENV
+        # mechanism (the `gitea.*` vs `github.*` expression contexts are
+        # just aliases of each other for `${{ }}` templating).
+        run: |
+          echo "registry=${REGISTRY:-git.maro.run}" >> "$GITHUB_OUTPUT"
+          echo "repo=${REGISTRY_REPO:-maro/anouma}" >> "$GITHUB_OUTPUT"
+          echo "version=${{ github.ref_name }}" >> "$GITHUB_OUTPUT"
+        env:
+          REGISTRY: git.maro.run
+          REGISTRY_REPO: maro/anouma
+
+      - name: Log in to registry
+        run: echo "${{ secrets.REGISTRY_PASSWORD }}" | docker login "${{ steps.image.outputs.registry }}" -u "${{ secrets.REGISTRY_USERNAME }}" --password-stdin
+
+      - name: Build image
+        run: |
+          IMAGE="${{ steps.image.outputs.registry }}/${{ steps.image.outputs.repo }}"
+          VERSION="${{ steps.image.outputs.version }}"
+          docker build -t "$IMAGE:$VERSION" -t "$IMAGE:latest" .
+
+      - name: Push image
+        run: |
+          IMAGE="${{ steps.image.outputs.registry }}/${{ steps.image.outputs.repo }}"
+          VERSION="${{ steps.image.outputs.version }}"
+          docker push "$IMAGE:$VERSION"
+          docker push "$IMAGE:latest"
+
+      - name: Deploy to production
+        env:
+          DEPLOY_HOST: ${{ secrets.DEPLOY_HOST }}
+          DEPLOY_PORT: ${{ secrets.DEPLOY_PORT }}
+          DEPLOY_USER: ${{ secrets.DEPLOY_USER }}
+          DEPLOY_SSH_KEY: ${{ secrets.DEPLOY_SSH_KEY }}
+          # Optional: pin the exact host key instead of trusting it on
+          # first connect (see DEPLOYMENT.md). Safe to leave unset.
+          DEPLOY_HOST_KEY: ${{ secrets.DEPLOY_HOST_KEY }}
+          VERSION: ${{ steps.image.outputs.version }}
+        run: |
+          set -euo pipefail
+          umask 077
+          key_file="$(mktemp)"
+          known_hosts_file="$(mktemp)"
+          trap 'rm -f "$key_file" "$known_hosts_file"' EXIT
+
+          printf '%s\n' "$DEPLOY_SSH_KEY" > "$key_file"
+          chmod 600 "$key_file"
+
+          if [ -n "${DEPLOY_HOST_KEY:-}" ]; then
+            printf '%s\n' "$DEPLOY_HOST_KEY" > "$known_hosts_file"
+          else
+            ssh-keyscan -p "${DEPLOY_PORT:-22}" "$DEPLOY_HOST" > "$known_hosts_file" 2>/dev/null
+          fi
+
+          # The forced command in the server's authorized_keys (see
+          # setup.sh) ignores this and always runs deploy.sh itself — the
+          # string below only ever reaches it via $SSH_ORIGINAL_COMMAND.
+          ssh -i "$key_file" -o UserKnownHostsFile="$known_hosts_file" -p "${DEPLOY_PORT:-22}" \
+            "${DEPLOY_USER}@${DEPLOY_HOST}" "deploy ${VERSION}"