refactor: enforce new GameOptions signature for useGame

- Remove old signature support (cols, rows, platformHook)
- useGame now requires GameOptions object only
- Update example app to use new signature
- Signature: useGame(options, platformHook?)

example/src/App.tsx

@@ -3,7 +3,7 @@ import "@vimazing/vim-snake/game.css";
 import { useKeyBindings } from "./useKeyBindings";
 
 function App() {
-  const { containerRef, gameStatus, scoreManager, keyLog, score, level } = useGame(30, 20, useKeyBindings);
+  const { containerRef, gameStatus, scoreManager, keyLog, score, level } = useGame({ cols: 30, rows: 20 }, useKeyBindings);
 
   const formatTime = (ms: number) => {
     const seconds = Math.floor(ms / 1000);