Rewrite core game logic to fix 10 critical bugs violating poker rules:
- Add betMatched flag to separate chip tracking from bet-matching state
- Implement last-aggressor tracking for proper betting round completion
- Rewrite all action functions with validation enforcement
- Add side pot support for multi-level all-in scenarios
- Replace nested setTimeout AI turns with async promise chain
- Add aiActing guard to prevent race conditions during AI play
- Fix currentTurn advancement to always land on active players