feat(09-04): add test job to CI pipeline

- Add test job with type checking, unit tests, and E2E tests
- Install Playwright browsers for E2E testing
- Upload coverage and playwright reports as artifacts
- Build job now depends on test job (fail-fast)

.gitea/workflows/build.yaml

@@ -15,7 +15,48 @@ env:
   IMAGE_NAME: admin/taskplaner
 
 jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        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 check -- --output machine
+
+      - name: Install Playwright browsers
+        run: npx playwright install --with-deps chromium
+
+      - name: Run unit tests with coverage
+        run: npm run test:coverage
+
+      - name: Run E2E tests
+        run: npm run test:e2e
+        env:
+          CI: true
+
+      - name: Upload test artifacts
+        uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: test-results
+          path: |
+            coverage/
+            playwright-report/
+            test-results/
+          retention-days: 7
+
   build:
+    needs: test
     runs-on: ubuntu-latest
     steps:
       - name: Checkout