8.2GitHub Actions: Complete Performance Budget Workflow

# .github/workflows/performance-budget.yml
name: Performance Budget Check
on:
  pull_request:
    branches: [main]

jobs:
  lighthouse:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: 24
          cache: npm

      - name: Install dependencies and build
        run: npm ci && npm run build

      - name: Deploy preview
        run: npm run deploy:preview
        env:
          PREVIEW_TOKEN: ${{ secrets.PREVIEW_TOKEN }}

      - name: Run Lighthouse CI
        uses: treosh/lighthouse-ci-action@v11
        with:
          configPath: ./lighthouserc.json
          uploadArtifacts: true
          temporaryPublicStorage: true

      - name: Check bundle size budget
        run: npx bundlesize --config bundlesize.config.json

      - name: Check API response time budget
        run: |
          FAILED=0
          for endpoint in "/api/products" "/api/cart" "/api/search?q=test"; do
            RESPONSE_TIME=$(curl -o /dev/null -s -w '%{time_total}' \
              "https://staging.example.com${endpoint}")
            echo "$endpoint: ${RESPONSE_TIME}s"
            if (( $(echo "$RESPONSE_TIME > 0.5" | bc -l) )); then
              echo "FAIL: $endpoint exceeded 500ms budget (actual: ${RESPONSE_TIME}s)"
              FAILED=1
            fi
          done
          if [ "$FAILED" -eq 1 ]; then
            exit 1
          fi

      - name: Post results as PR comment
        if: always()
        uses: marocchino/sticky-pull-request-comment@v2
        with:
          header: performance-budget
          path: lighthouse-results-summary.md