- Add .gitattributes with text=auto eol=lf for all text files
- Renormalize all files in index to LF line endings
- Fixes massive whitespace-only diffs between main and feature branch
- Add tests/contracts/engine_contract.py with shared Engine/Session tests
- TestKokoroEngineContract and TestSuperTonicEngineContract inherit from it
- Eliminates protocol test duplication between plugins
- Any new plugin just inherits EngineContractMixin to verify compliance