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.md

@@ -314,6 +314,112 @@ pattern(r, c) = (3 * (r % 3) + floor(r / 3) + c) % 9 + 1
 
 ---
 
-## Iteration 5: [Pending]
+## Iteration 5: Phase 30 - useGameStatus Hook
+
+**Date**: 2025-01-22
+
+### Goals
+- Extract game status logic into dedicated hook
+- Follow vim-maze architecture pattern
+- Clean separation of concerns
+- Reusable state machine
+
+### Tasks Completed
+
+#### 1. Created useGameStatus Module
+**File Structure**:
+```
+src/useGameStatus/
+├── index.ts              # Public exports
+├── types.ts              # GameStatus, GameStatusManager
+└── useGameStatus.ts      # Hook implementation
+```
+
+#### 2. Implemented State Machine
+**States**:
+- `waiting` - Initial state, awaiting start
+- `started` - Game in progress
+- `paused` - Game temporarily paused
+- `game-over` - Game lost
+- `game-won` - Game completed
+
+**State Transitions**:
+```
+waiting ──startGame()──> started
+               ▲            │
+               │            │ togglePause()
+               │            ▼
+              quitGame()  paused
+                           │
+                           │ togglePause()
+                           ▼
+                        started
+```
+
+#### 3. Hook API
+```typescript
+const gameStatusManager = useGameStatus();
+const {
+  gameStatus,        // Current state
+  setGameStatus,     // Direct setter (for special cases)
+  startGame,         // waiting → started
+  togglePause,       // started ↔ paused
+  quitGame,          // * → waiting
+} = gameStatusManager;
+```
+
+#### 4. Updated useGame
+- Removed inline `useState<GameStatus>`
+- Uses `useGameStatus()` hook
+- Spreads `gameStatusManager` into `GameManager`
+- Cleaner, more maintainable code
+
+#### 5. Updated Type System
+**types.ts**:
+- Imports `GameStatus` and `GameStatusManager` from useGameStatus
+- Re-exports for public API
+- `GameManager` extends `GameStatusManager` (intersection type)
+- Avoids duplication, single source of truth
+
+### Technical Details
+
+**Simpler than vim-maze**:
+- No intermediate states (no 'has-key' equivalent)
+- Straightforward: waiting → started → won/over
+- Pause is optional toggle, not a separate flow
+
+**Hook Composition**:
+```typescript
+// In useGame
+const gameStatusManager = useGameStatus();
+const { gameStatus } = gameStatusManager;
+
+// Compose into GameManager
+const gameManager = {
+  ...gameStatusManager,  // gameStatus, startGame, etc.
+  // ... other managers
+};
+```
+
+**Type Safety**:
+- `GameManager` extends `GameStatusManager`
+- All status methods available on gameManager
+- Full TypeScript inference throughout
+
+### Build Status
+- ✅ TypeScript compiles cleanly
+- ✅ Example app builds successfully
+- ✅ No breaking changes to public API
+
+### Next Steps
+- Phase 40: useCursor Hook Composition
+  - useCellEditor (analog to useHero)
+  - useVimMotions
+  - useGameKeys
+  - useCursorRender
+
+---
+
+## Iteration 6: [Pending]
 
 *To be filled as implementation progresses...*