feat(ci): add format check and tests to PR validation pipeline

- Add format:check step (prettier --check, hard fail)
- Make lint step a hard fail (remove || echo fallback)
- Add test step (soft fail for now — coverage is thin)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -567,8 +567,14 @@ jobs:
       - name: Type check
         run: pnpm run type-check
 
+      - name: Format check
+        run: pnpm run format:check
+
       - name: Lint
-        run: pnpm run lint || echo "Lint warnings found"
+        run: pnpm run lint
+
+      - name: Test
+        run: pnpm run test || true
 
       - name: Security Audit
         run: |