Introduce Tri-Ominoes, a triangular grid tile-placement game for 2–4 players. The implementation includes a pure rules engine (`TriominoesLogic`), triangular grid geometry and data (`TriominoesData`), a Phaser scene (`TriominoesGame`), and a heuristic AI with 5 skill levels (`TriominoesAI`).
Key features:
- Corner-matching tile placement on an equilateral triangular grid
- Scoring with pip sums, hexagon-closing bonuses, and going-out rewards
- Draw-from-pool and pass mechanics with forced pass when blocked
- Animated AI tile placement from opponent portraits
- Board panning and re-centering for large play areas
- Game-over modal with final scores and history posting
Also updates the game registry, scene dispatch, opponent select skill controls, and adds two new character portraits (beth, blackwind).
