feat: add GitHub Actions workflow for Chrome Web Store publishing

Add automated publishing workflow that:
- Triggers on GitHub releases and manual dispatch
- Runs type checking and tests as quality gates
- Builds extension and publishes to Chrome Web Store
- Uses existing GitHub secrets for authentication

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: andyleap

.github/workflows/publish-chrome-extension.yml

@@ -0,0 +1,60 @@
+name: Publish Chrome Extension
+
+on:
+  # Trigger when a GitHub release is published
+  release:
+    types: [published]
+
+  # Allow manual triggering for testing
+  workflow_dispatch:
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run type check
+        run: npm run typecheck
+
+      - name: Run tests
+        run: npm test
+
+      - name: Build extension
+        run: npm run build
+
+      - name: Extract version from manifest
+        id: version
+        run: |
+          VERSION=$(node -p "require('./manifest.json').version")
+          echo "VERSION=$VERSION" >> $GITHUB_ENV
+          echo "Extension version: $VERSION"
+
+      - name: Upload to Chrome Web Store
+        uses: mnao305/chrome-extension-upload@v5.0.0
+        with:
+          file-path: builds/${{ env.VERSION }}.zip
+          extension-id: ${{ secrets.EXTENSION_ID }}
+          client-id: ${{ secrets.CLIENT_ID }}
+          client-secret: ${{ secrets.CLIENT_SECRET }}
+          refresh-token: ${{ secrets.REFRESH_TOKEN }}
+          publish: true
+
+      - name: Upload build artifact
+        uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: extension-build-${{ env.VERSION }}
+          path: builds/${{ env.VERSION }}.zip
+          retention-days: 90