feat: add SynthQuest game mode with World 1 (Waves) — 8 puzzle levels

Gamified synth learning inspired by Turing Complete. Progressive puzzle
system teaches oscillators, waveforms, frequency, and mixing through
hands-on module patching. Includes world map, level progression with
3-star rating, target audio playback, solution validation, and
localStorage persistence. Sandbox mode still accessible via button.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/App.jsx

@@ -9,7 +9,7 @@ import ModulePalette from './components/ModulePalette.jsx';
 import PresetModal from './components/PresetModal.jsx';
 import { CHIPTUNE_PRESET } from './presets/chiptune.js';
 
-export default function App() {
+export default function App({ onSwitchToGame }) {
   const [, forceUpdate] = useState(0);
   const containerRef = useRef(null);
   const portPositions = useRef({});
@@ -205,6 +205,11 @@ export default function App() {
     <div className="app">
       {/* Toolbar */}
       <div className="toolbar">
+        {onSwitchToGame && (
+          <button className="toolbar-btn" onClick={onSwitchToGame} style={{ color: 'var(--yellow)' }}>
+            🎮 Game
+          </button>
+        )}
         <span className="toolbar-title">Reaktor</span>
         <div className="toolbar-sep" />
         <button className={`toolbar-btn ${state.isRunning ? 'active' : ''}`} onClick={handleToggleAudio}>