Agent Skills: code-ratchets

Implement code quality ratchets to prevent proliferation of deprecated patterns. Use when (1) migrating away from legacy code patterns, (2) enforcing gradual codebase improvements, (3) preventing copy-paste proliferation of deprecated practices, or (4) setting up pre-commit hooks to count and limit specific code patterns. A ratchet fails if pattern count exceeds OR falls below expected—ensuring patterns never increase and prompting updates when they decrease.