## 2025-02-12 - Missing Test Cleanup **Vulnerability:** Tests in `src/pages/__tests__/Contact.test.tsx` were failing with duplicate elements because `cleanup()` was not being called between tests. **Learning:** `testing-library/react` usually handles cleanup automatically, but in this environment/setup, explicit `cleanup()` and `document.body.innerHTML = ''` in `afterEach` is required to prevent DOM state leakage. **Prevention:** Always include explicit `cleanup()` in `afterEach` blocks when writing component tests in this repository.