- ConnectionManager: Add redis_factory constructor parameter
- GameService: Add engine_factory constructor parameter
- AuthHandler: New class replacing standalone functions with
token_verifier and conn_manager injection
- Update all tests to use constructor DI instead of patch()
- Update CLAUDE.md with factory injection patterns
- Update services README with new patterns
- Add socketio README documenting AuthHandler and events
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>