feat(builds): populate builds page with Linux and Android history (#94)

The builds page at /builds/ was empty because generate-build-history
only ran inside deploy-playstore; if that job failed early (e.g. Play
Store secrets not configured) the website was never updated, and the
build-linux job never triggered a website update at all.

Changes:
- generate_build_history.py: extend to cover Linux tarballs in addition
  to Android APKs, capped at MAX_BUILDS_PER_PLATFORM (30) each
- Taskfile: add website-publish task (generate-build-history +
  website-deploy), exclude *.tar.gz from rsync, update descriptions
- .forgejo/workflows/ci.yml: add publish-website job that waits for
  both build-linux and deploy-playstore (using always() so it runs
  even when deploy-playstore fails), then removes the duplicate
  generate/deploy steps from deploy-playstore
- .github/workflows/ci.yml: add deploy job that deploys Linux build,
  generates build history, builds Hugo site, and rsyncs to server
- .gitignore: ignore website/content/builds/_index.md (generated),
  Python __pycache__, and widget test failure screenshots
- stalwart-dev/integration_ui_test.sh: use ${USER:-$(id -un)} for
  robustness in environments where USER is unset
- scripts/test_generate_build_history.py: unit tests for parse_builds
  and render_entries covering both platforms

Generated content (builds/_index.md and per-day pages) is not tracked
in git; it is produced at CI time and rsynced to the server.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -151,3 +151,99 @@ jobs:
 
       - name: Build Linux release
         run: flutter build linux --release
+
+  deploy:
+    name: Deploy Linux build & publish website
+    runs-on: ubuntu-latest
+    needs: build-linux
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+    env:
+      SSH_HOST: ${{ secrets.SSH_HOST }}
+      SSH_USER: ${{ secrets.SSH_USER }}
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install build & deploy dependencies
+        run: |
+          sudo apt-get update -q
+          sudo apt-get install -y --no-install-recommends \
+            libgtk-3-dev pkg-config cmake ninja-build clang \
+            libsecret-1-dev hugo rsync
+
+      - uses: subosito/flutter-action@v2
+        with:
+          flutter-version: "3.41.6"
+          channel: stable
+          cache: true
+
+      - name: Cache pub packages
+        uses: actions/cache@v4
+        with:
+          path: ~/.pub-cache
+          key: pub-${{ hashFiles('pubspec.lock') }}
+          restore-keys: pub-
+
+      - name: Install dependencies
+        run: flutter pub get
+
+      - name: Generate Drift code
+        run: flutter pub run build_runner build --delete-conflicting-outputs
+
+      - name: Generate changelog
+        run: |
+          mkdir -p assets
+          git log -n 50 \
+            --pretty=format:'* %ad [%h](https://codeberg.org/guettli/sharedinbox/commit/%H): %s' \
+            --date=short > assets/changelog.txt
+
+      - name: Setup SSH
+        run: |
+          mkdir -p ~/.ssh
+          printf '%s\n' "${{ secrets.SSH_PRIVATE_KEY }}" > ~/.ssh/id_ed25519
+          chmod 600 ~/.ssh/id_ed25519
+
+      - name: Build Linux release
+        run: |
+          HASH=$(git rev-parse --short HEAD)
+          flutter build linux --release --no-pub --dart-define=GIT_HASH=$HASH
+
+      - name: Deploy Linux build to server
+        run: |
+          HASH=$(git rev-parse --short HEAD)
+          DATE_PATH=$(date -u +%Y/%m/%d)
+          REMOTE_DIR="public_html/builds/$DATE_PATH"
+          TARBALL="sharedinbox-linux-amd64-$HASH.tar.gz"
+          tar -czf /tmp/$TARBALL -C build/linux/x64/release bundle
+          ssh -o StrictHostKeyChecking=no "$SSH_USER@$SSH_HOST" "mkdir -p $REMOTE_DIR"
+          scp -o StrictHostKeyChecking=no /tmp/$TARBALL "$SSH_USER@$SSH_HOST:$REMOTE_DIR/$TARBALL"
+          DOWNLOAD_URL="https://sharedinbox.de/builds/$DATE_PATH/$TARBALL"
+          EXISTING=$(ssh -o StrictHostKeyChecking=no "$SSH_USER@$SSH_HOST" \
+            "cat public_html/latest.json 2>/dev/null || echo '{}'")
+          WINDOWS_URL=$(echo "$EXISTING" | \
+            python3 -c "import json,sys; d=json.load(sys.stdin); print(d.get('windows',''))" \
+            2>/dev/null || true)
+          if [ -n "$WINDOWS_URL" ]; then
+            echo "{\"version\":\"$HASH\",\"linux\":\"$DOWNLOAD_URL\",\"windows\":\"$WINDOWS_URL\"}" | \
+              ssh -o StrictHostKeyChecking=no "$SSH_USER@$SSH_HOST" "cat > public_html/latest.json"
+          else
+            echo "{\"version\":\"$HASH\",\"linux\":\"$DOWNLOAD_URL\"}" | \
+              ssh -o StrictHostKeyChecking=no "$SSH_USER@$SSH_HOST" "cat > public_html/latest.json"
+          fi
+
+      - name: Generate build history pages
+        run: python3 scripts/generate_build_history.py
+
+      - name: Build website
+        env:
+          HUGO_PARAMS_GITVERSION: ${{ github.sha }}
+        run: hugo --source website --minify
+
+      - name: Deploy website
+        run: |
+          rsync -avz --delete \
+            --exclude='*.apk' \
+            --exclude='*.tar.gz' \
+            -e "ssh -o StrictHostKeyChecking=no" \
+            website/public/ \
+            "$SSH_USER@$SSH_HOST:public_html/"