feat: add Worlds 2-3, patch persistence, and zoom controls

- World 2 (Filtros): 8 levels teaching filters, resonance, LFO modulation, acid bass
- World 3 (Envelopes): 8 levels teaching VCA, ADSR, pluck, tremolo, full synth lead
- Star-based world unlock system (12 stars for W2, 24 for W3)
- Level patch persistence: auto-saves player patches, restores on revisit
- Google Maps-style zoom controls (+/−/reset) in both puzzle and sandbox views
- Multi-world navigation in GameApp and WorldMap
- Target audio now supports filter chain for World 2 levels

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

src/game/GameApp.jsx

@@ -2,43 +2,58 @@ import React, { useState, useCallback } from 'react';
 import WorldMap from './WorldMap.jsx';
 import PuzzleView from './PuzzleView.jsx';
 import { WORLD_1 } from './levels/world1.js';
+import { WORLD_2 } from './levels/world2.js';
+import { WORLD_3 } from './levels/world3.js';
+
+const allWorlds = [WORLD_1, WORLD_2, WORLD_3];
 
 export default function GameApp({ onSwitchToSandbox }) {
-  const [view, setView] = useState('map'); // 'map' | 'puzzle'
+  const [view, setView] = useState('map');
   const [currentLevel, setCurrentLevel] = useState(null);
   const [currentLevelIndex, setCurrentLevelIndex] = useState(0);
+  const [currentWorld, setCurrentWorld] = useState(null);
 
-  const worldLevels = WORLD_1.levels;
-
-  const handleSelectLevel = useCallback((level) => {
-    const idx = worldLevels.findIndex(l => l.id === level.id);
+  const handleSelectLevel = useCallback((level, world) => {
+    const idx = world.levels.findIndex(l => l.id === level.id);
     setCurrentLevel(level);
     setCurrentLevelIndex(idx);
+    setCurrentWorld(world);
     setView('puzzle');
-  }, [worldLevels]);
+  }, []);
 
   const handleBack = useCallback(() => {
     setView('map');
     setCurrentLevel(null);
+    setCurrentWorld(null);
   }, []);
 
   const handleNextLevel = useCallback(() => {
+    if (!currentWorld) return;
     const nextIdx = currentLevelIndex + 1;
-    if (nextIdx < worldLevels.length) {
-      setCurrentLevel(worldLevels[nextIdx]);
+    if (nextIdx < currentWorld.levels.length) {
+      setCurrentLevel(currentWorld.levels[nextIdx]);
       setCurrentLevelIndex(nextIdx);
     } else {
-      setView('map');
+      // Move to next world's first level if unlocked
+      const worldIdx = allWorlds.findIndex(w => w.id === currentWorld.id);
+      if (worldIdx < allWorlds.length - 1) {
+        const nextWorld = allWorlds[worldIdx + 1];
+        setCurrentWorld(nextWorld);
+        setCurrentLevel(nextWorld.levels[0]);
+        setCurrentLevelIndex(0);
+      } else {
+        setView('map');
+      }
     }
-  }, [currentLevelIndex, worldLevels]);
+  }, [currentLevelIndex, currentWorld]);
 
-  if (view === 'puzzle' && currentLevel) {
+  if (view === 'puzzle' && currentLevel && currentWorld) {
     return (
       <PuzzleView
         key={currentLevel.id}
         level={currentLevel}
         levelIndex={currentLevelIndex}
-        worldLevels={worldLevels}
+        worldLevels={currentWorld.levels}
         onBack={handleBack}
         onNextLevel={handleNextLevel}
       />