feat: implement Phase 30 - useGameStatus hook

Extract game status logic into dedicated hook following vim-maze pattern:

New Module Structure:
- src/useGameStatus/types.ts: GameStatus and GameStatusManager types
- src/useGameStatus/useGameStatus.ts: Hook implementation
- src/useGameStatus/index.ts: Public exports

Hook Implementation:
- State machine with 5 states (waiting/started/paused/game-over/game-won)
- Methods: startGame, togglePause, quitGame, setGameStatus
- Clean state transitions with useState
- Simpler than vim-maze (no intermediate 'has-key' state)

Updated Core Files:
- src/useGame.ts: Use useGameStatus() instead of inline useState
  - Compose gameStatusManager into GameManager
  - Cleaner separation of concerns

- src/types.ts: Import and re-export GameStatus types
  - GameManager extends GameStatusManager (intersection type)
  - Single source of truth for status types

- src/index.ts: Export useGameStatus hook publicly

Benefits:
- Reusable state machine
- Easier to test in isolation
- Follows unified API architecture
- Matches vim-maze patterns

State Transitions:
waiting → startGame() → started ↔ togglePause() ↔ paused
started → (win/lose) → game-won/game-over
* → quitGame() → waiting

Phase 30 complete. Next: Phase 40 (useCursor composition).

IMPLEMENTATION_PLAN.md

@@ -93,10 +93,12 @@ src/
 
 ### Phase 30: useGameStatus Hook
 
-- [ ] Implement GameStatus state machine
+- [x] Implement GameStatus state machine
   - 'waiting' → 'started' → 'game-won' / 'game-over'
   - 'paused' state support
-- [ ] Methods: startGame, togglePause, quitGame, setGameStatus
+- [x] Methods: startGame, togglePause, quitGame, setGameStatus
+- [x] Extract from inline useState in useGame
+- [x] Create dedicated hook following vim-maze pattern
 
 ### Phase 40: useCursor Hook Composition