Implement comprehensive test suite for four core quality gates:
- BuildGate: Tests mypy type checking enforcement
- LintGate: Tests ruff linting with warnings as failures
- TestGate: Tests pytest execution requiring 100% pass rate
- CoverageGate: Tests coverage enforcement with 85% minimum
All tests follow TDD methodology - written before implementation.
Total: 36 tests covering success, failure, and edge cases.
Related to #147
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Jason Woltje
0af93d1ef4