Fix bus collision with smashed items by clearing bus category from item mask

src/data/levels/level01.js

@@ -383,6 +383,12 @@ export default {
     ] },
   ],
   obstacles: [],
+  items: [
+    { type: "tv", mode: "gravity", x: 5754, y: 444 },
+    { type: "cone", mode: "gravity", x: 2479, y: 369 },
+    { type: "cone", mode: "gravity", x: 2721, y: 219 },
+    { type: "cone", mode: "gravity", x: 2521, y: 136 },
+  ],
   goal: { x: 25420, y: 406, width: 280, height: 640 },
   cameraBounds: { x: -600, y: -522, width: 27060, height: 2414 },
 };

src/entities/SmashItemManager.js

@@ -112,11 +112,24 @@ export default class SmashItemManager {
   }
 
   // The smash: swap to the smashed frame, make the body dynamic (so the
-  // launch actually moves it), and give it the up-and-forward impulse.
+  // launch actually moves it), give it the up-and-forward impulse, and clear
+  // the bus out of its collision mask so the bus drives straight through it.
   _smash(item) {
     const image = item.image;
     const dirX = Math.sign(this.bus.chassis.body.velocity.x) >= 0 ? 1 : -1;
 
+    // From this moment on the smashed item is no longer solid to the bus.
+    // Clear the bus's category bit out of the item's collision mask so the
+    // broadphase skips every item<->bus pair (Detector.canCollide only
+    // considers a pair when each side's mask includes the other's category -
+    // see the vendored build). Set on the raw matter body directly: that's the
+    // exact field canCollide reads, and matter-js recomputes pairs every step,
+    // so this takes effect on the very next physics step. The item keeps its
+    // mask against everything ELSE (terrain, other items, kids), so it still
+    // lands and rests where it flies - only the bus is exempted. This is what
+    // makes the bus "drive through" a smashed prop instead of bumping it.
+    image.body.collisionFilter.mask = 0xffffffff & ~this.bus.busCategory;
+
     // setStatic(false) (Phaser component, same as in _buildItem) restores
     // the body's saved real mass/inertia - matter-js stashed them when the
     // body was made static - so the velocity math below is meaningful. For