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).

src/types.ts

@@ -1,8 +1,9 @@
 import type { RefObject } from 'react';
+import type { GameStatus, GameStatusManager } from './useGameStatus/types';
 
 export type Difficulty = 'easy' | 'medium' | 'hard';
 
-export type GameStatus = 'waiting' | 'started' | 'paused' | 'game-over' | 'game-won';
+export type { GameStatus, GameStatusManager };
 
 export type GameOptions = {
   difficulty?: Difficulty;
@@ -13,11 +14,6 @@ export type KeyLogEntry = { key: string; timestamp: number };
 export type GameManager = {
   containerRef: RefObject<HTMLDivElement | null>;
   renderBoard: () => void;
-  gameStatus: GameStatus;
-  setGameStatus: (status: GameStatus) => void;
-  startGame: () => void;
-  togglePause: (pause?: boolean) => void;
-  quitGame: () => void;
   cursor: any;
   scoreManager: {
     timeValue: number;
@@ -27,4 +23,4 @@ export type GameManager = {
   keyLog: KeyLogEntry[];
   clearKeyLog: () => void;
   getKeyLog: () => KeyLogEntry[];
-};
+} & GameStatusManager;