chore: enable test coverage reporting in CI pipeline

- Updated `.github/workflows/ci.yml` to include the `--coverage` flag when running tests.
- This ensures test coverage data is generated and can be uploaded to Codecov for better analysis.

.github/workflows/ci.yml

@@ -29,7 +29,7 @@ jobs:
         run: npm run lint
 
       - name: Test
-        run: npm run test
+        run: npm run test -- --coverage
 
       - name: Upload coverage reports to Codecov
         uses: codecov/codecov-action@v5