ci: add GitHub Actions workflow for test suite

- Added test.yml workflow to run on PRs and pushes to main/master
- Runs server tests with coverage on every PR
- Uploads coverage reports to Codecov
- Added test:server:coverage script to root package.json
- Coverage thresholds enforced: 80% lines/functions, 75% branches

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.github/workflows/test.yml

@@ -0,0 +1,45 @@
+name: Test Suite
+
+on:
+  pull_request:
+    branches:
+      - "*"
+  push:
+    branches:
+      - main
+      - master
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: "npm"
+          cache-dependency-path: package-lock.json
+
+      - name: Install dependencies
+        # Use npm install instead of npm ci to correctly resolve platform-specific
+        # optional dependencies (e.g., @tailwindcss/oxide, lightningcss binaries)
+        run: npm install
+
+      - name: Run server tests with coverage
+        run: npm run test:server:coverage
+        env:
+          NODE_ENV: test
+
+      - name: Upload coverage reports
+        uses: codecov/codecov-action@v4
+        if: always()
+        with:
+          files: ./apps/server/coverage/coverage-final.json
+          flags: server
+          name: server-coverage
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}

package.json

@@ -24,6 +24,7 @@
     "test": "npm run test --workspace=apps/app",
     "test:headed": "npm run test:headed --workspace=apps/app",
     "test:server": "npm run test --workspace=apps/server",
+    "test:server:coverage": "npm run test:cov --workspace=apps/server",
     "dev:marketing": "npm run dev --workspace=apps/marketing"
   }
 }