- Implement Checkers and Chess with complete Phaser UI, pure logic modules, and alpha-beta minimax AI opponents featuring a 1-5 skill model.
- Extend opponent skill selector to support Checkers and Chess.
- Register new games in frontend routing and backend registry.
- Improve Dominion game UX: add persistent phase dials and turn arrow indicators, add confirmation prompts for ending actions/turns, and refine card animation timings.
- Update Dominion card asset files.
