Fix all-kids-lost failing too early; add bus-fell fail condition

The level now only fails on "all kids lost" once every ejected kid has
settled outside the bus (restSpeed/settleDuration hysteresis) or fallen
past the camera bounds, giving a rescue window after a jump. Also fails
when the bus itself drops below the level, and guards the compartment
clamp with a distance radius so far-away kids aren't yanked toward the
bus.

src/config.js

@@ -53,6 +53,17 @@ export const BUS = {
   compartmentFloorThickness: 10 * WORLD_SCALE,
   compartmentFloorY: 12 * WORLD_SCALE,
   compartmentTopY: -60 * WORLD_SCALE,
+  // The clamp in KidManager only makes sense as a same-tick tunnel-through
+  // guard against the compartment's OWN fixtures - a kid further than this
+  // from the chassis was never inside the compartment to begin with, and
+  // local-frame coordinates alone can't tell "just tunneled through" apart
+  // from "resting somewhere else in the level entirely" without a distance
+  // check like this (a kid at rest far away can still end up with local
+  // coordinates that look like a boundary violation purely because the
+  // chassis itself has moved since). Generous enough to still catch a
+  // genuinely fast tunnel-through, nowhere near large enough to reach a kid
+  // that's actually elsewhere on the level.
+  compartmentClampRadius: 400 * WORLD_SCALE,
 
   // Density/friction/stiffness/damping are dimensionless ratios, not pixel
   // distances - they don't scale with WORLD_SCALE.
@@ -138,6 +149,23 @@ export const KID = {
   // bus does, Snuggle-Truck style. Primary tuning knob for "how floaty,"
   // not physically derived.
   ejectedGravityScale: 0.35,
+  // How slow (raw Matter velocity magnitude, same convention as everything
+  // else that reads body.velocity directly in this codebase) an ejected
+  // kid needs to be moving to count as "settled" outside the bus - used by
+  // PlayScene to delay the all-kids-lost failure until every kid has
+  // actually landed and stopped, not the instant the last one leaves the
+  // compartment, so a jump that pops everyone loose still leaves a window
+  // to drive back underneath and catch them. Calibrated via a headless
+  // matter-js simulation of a kid landing with realistic horizontal speed
+  // under ejectedGravityScale: settles below this within ~3s of landing,
+  // fully stops within ~10s - tune by playtesting if that feels off.
+  restSpeedThreshold: 1,
+  // Must stay below restSpeedThreshold continuously for this long to count
+  // as settled, not just an instant - a kid arcing under weak gravity can
+  // pass through near-zero speed for a single tick right at the peak of
+  // its jump while still very much airborne (about to fall again, not
+  // landed), so a momentary dip alone isn't proof it's actually stopped.
+  settleDurationMs: 500,
 };
 
 export const CAMERA = {

src/entities/Kid.js

@@ -12,6 +12,7 @@ export default class Kid {
     this.bus = bus;
     this.seatIndex = seatIndex;
     this.state = 'aboard'; // aboard | ejected
+    this._slowSince = null; // see isSettled()
 
     const worldPos = bus.getSeatWorldPosition(seatIndex);
 
@@ -73,6 +74,23 @@ export default class Kid {
     this.image.body.ignoreGravity = false;
   }
 
+  // True once this kid's speed has stayed below KID.restSpeedThreshold for
+  // KID.settleDurationMs straight - used by PlayScene to tell "actually
+  // landed and stopped" apart from a kid just passing through low speed for
+  // an instant at the peak of its arc while still airborne. Only meaningful
+  // to call repeatedly (e.g. every frame) once ejected - the timer resets
+  // itself the moment speed rises back above threshold.
+  isSettled(now) {
+    const v = this.image.body.velocity;
+    const speed = Math.hypot(v.x, v.y);
+    if (speed >= KID.restSpeedThreshold) {
+      this._slowSince = null;
+      return false;
+    }
+    if (this._slowSince === null) this._slowSince = now;
+    return now - this._slowSince >= KID.settleDurationMs;
+  }
+
   destroy() {
     this.image.destroy();
   }

src/scenes/LevelFailedScene.js

@@ -4,6 +4,7 @@ import { createButton } from '../util/ui.js';
 
 const REASON_TEXT = {
   'all-kids-lost': 'Every kid got thrown off the bus!',
+  'bus-fell': 'The bus fell into the gap!',
 };
 
 export default class LevelFailedScene extends Phaser.Scene {

src/scenes/PlayScene.js

@@ -55,6 +55,8 @@ export default class PlayScene extends Phaser.Scene {
     this.bus.applyIntent(intent);
     this.cameraRig.update();
     this._updateParallax();
+    this._checkBusFell();
+    this._checkAllKidsLost();
 
     if (DEBUG && this.debugText) {
       const g = this.gForceMonitor.lastGForce || 0;
@@ -121,6 +123,39 @@ export default class PlayScene extends Phaser.Scene {
     this.bgFar.tilePositionX = progress * this._bgFarPanRange;
   }
 
+  // A bus that's fallen past the bottom of the level's own camera bounds
+  // is somewhere the camera can never scroll down far enough to show again
+  // (that's the literal definition of "off screen" here) - treated the
+  // same as losing every kid, since there's no way to recover either.
+  _checkBusFell() {
+    if (this._isBelowCameraBounds(this.bus.chassis.y)) {
+      this.events.emit('level-failed', { reason: 'bus-fell' });
+    }
+  }
+
+  _isBelowCameraBounds(y) {
+    const bounds = this.level.cameraBounds;
+    return y > bounds.y + bounds.height;
+  }
+
+  // 0 kids aboard isn't itself a fail condition - KidManager just tracks
+  // who's still seated. A kid popped loose by a jump is still catchable
+  // (falls down through the compartment's open top and re-boards - see
+  // KidManager) right up until it's either settled outside the bus or lost
+  // down a gap, so the level only fails once EVERY kid has reached one of
+  // those two unrecoverable states, not the instant the last one leaves.
+  _checkAllKidsLost() {
+    if (this.kidManager.kidsAboardCount > 0) return;
+
+    const allUnrecoverable = this.kidManager.kids.every((kid) => {
+      return this._isBelowCameraBounds(kid.image.y) || kid.isSettled(this.time.now);
+    });
+
+    if (allUnrecoverable) {
+      this.events.emit('level-failed', { reason: 'all-kids-lost' });
+    }
+  }
+
   _buildGoal() {
     const goal = this.level.goal;
     this.goalBody = this.matter.add.rectangle(goal.x, goal.y, goal.width, goal.height, {

src/systems/KidManager.js

@@ -78,10 +78,11 @@ export default class KidManager {
         kidsAboard: this.kidsAboardCount,
         total: this.total,
       });
-
-      if (this.kidsAboardCount === 0) {
-        this.scene.events.emit('level-failed', { reason: 'all-kids-lost' });
-      }
+      // No level-failed here even at 0 aboard - PlayScene decides that once
+      // every kid has actually settled outside the bus (or fallen down a
+      // gap), not the instant the last one leaves, so a jump that pops
+      // everyone loose still leaves a window to drive back underneath and
+      // catch them (see PlayScene._checkAllKidsLost).
     }
   }
 
@@ -92,6 +93,16 @@ export default class KidManager {
   _clampToCompartment(kid, chassis, cos, sin) {
     const dx = kid.image.x - chassis.x;
     const dy = kid.image.y - chassis.y;
+
+    // A kid genuinely outside compartmentClampRadius was never inside the
+    // compartment this tick - skip it entirely, rather than let the below
+    // checks (which only bound ONE axis each) treat "far away in the other
+    // axis" as a boundary violation. Without this, a kid resting anywhere
+    // else in the level could get yanked toward wherever the bus currently
+    // is, since local-frame coordinates alone don't distinguish "just
+    // tunneled through" from "elsewhere entirely."
+    if (dx * dx + dy * dy > BUS.compartmentClampRadius * BUS.compartmentClampRadius) return;
+
     let localX = dx * cos + dy * sin;
     let localY = -dx * sin + dy * cos;
     let hitFloor = false;