Phase A: stability and performance

A1 Pooled particle system
- New ParticleManager owns 9 reusable Phaser emitters created once per scene
  (jump, explosion, powerup, puff, sparks, flame, wind, spring, speedline)
- BootScene generates reusable white textures (px_square/soft/streak/ring)
- GameScene burst helpers + EffectsManager flow effects now delegate to the
  pool instead of allocating rectangles + tweens every frame
- Quality auto-detect (low on mobile/small screens) cuts particle counts

A2 Fix high-speed landing tunneling
- Cap downward velocity at PHYSICS.maxFallSpeed (boosts unaffected)
- platformCollisionFilter now uses a swept deltaY one-way check so a fast
  fall can never be wrongly rejected or passed through

A3 Safe storage
- New utils/storage.js wraps localStorage with in-memory fallback so private
  mode / quota errors cannot crash the game; all access routed through it

A4-A6 Lifecycle and robustness
- Global error / unhandledrejection guard recovers to the menu
- GameScene auto-pauses on tab hidden and cleans up the cross-scene listener
  on shutdown; fps pacing + disableContextMenu in game config
- Moving platforms use a proper dynamic body instead of destroy()+new Body

Verified in-browser: menu + game load with zero console errors, all emitters
active, normal bouncing works, fall speed capped.

src/main.js

@@ -22,9 +22,33 @@ const config = {
       debug: false,
     },
   },
+  fps: {
+    target: 60,
+    min: 30,
+  },
+  disableContextMenu: true,
   scene: [BootScene, MenuScene, GameScene, GameOverScene],
   pixelArt: false,
   antialias: true,
 };
 
-window.game = new Game(config);
+const game = new Game(config);
+window.game = game;
+
+// Global crash guard: if an uncaught error happens during gameplay, recover to
+// the menu instead of leaving a frozen canvas.
+function recoverToMenu() {
+  try {
+    if (!game || !game.scene) return;
+    const inGame = game.scene.isActive('GameScene');
+    if (inGame) {
+      game.scene.stop('GameScene');
+      game.scene.start('MenuScene');
+    }
+  } catch (_) {
+    /* swallow — last-resort guard */
+  }
+}
+
+window.addEventListener('error', recoverToMenu);
+window.addEventListener('unhandledrejection', recoverToMenu);