[AUDIT] Increase Test Coverage from 6 tests

Critical: Low Test Coverage

Severity: CRITICAL

Current State

• Only 6 test files found
• Insufficient for production charts/visualization

Required Actions

1. Write unit tests (90% coverage)
2. Write integration tests (80% coverage)
3. Add visual regression tests
4. Enforce coverage in CI/CD

Definition of Done

• Minimum 80% test coverage
• All tests passing in CI/CD
• TDD enforced for new code