fix(web): mascot physics, drag reliability, and speech-bubble polish

Audits and fixes ground-teleport/flat-fall/toss-momentum physics bugs,
fixes drag getting stuck via missing pointercancel handling, replaces
sprite-based speech bubbles with real HTML text/emoji bubbles, adds
drag-onto-icon "investigate" reactions and idle chatter, merges the
name badge and reaction bubble into one floating element, and caps the
bubble to one line with a teleprompter-style auto-scroll instead of
ellipsizing overflow text.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/lib/mascot/MascotLayer.svelte

@@ -48,9 +48,11 @@
     reactAnim: null,
     bounds: { w: 800, h: 600 },
     groundY: 600,
-    bubble: null,
+    bubbleText: null,
     bubbleUntil: 0,
-    blinkUntil: 0
+    blinkUntil: 0,
+    fallPhaseAt: 0,
+    investigateOnLand: false
   })
 
   let menuPos = $state<{ x: number; y: number } | null>(null)
@@ -105,7 +107,7 @@
   function onPet() {
     // Plain-click pet: briefly show a happy bubble. The actual model.pet()
     // call already happened in Mascot.svelte.
-    runtime.bubble = '/mascot/bubble-love.png'
+    runtime.bubbleText = '❤️'
     runtime.bubbleUntil = performance.now() + 1500
   }
 
@@ -149,6 +151,13 @@
     // behind it.
     const detach = attachStimuli((reaction) => {
       if (getModel().stage === 'egg') return
+      // Dragging always wins — never let a reaction interrupt an active
+      // drag (previously it could visually flash a reaction animation
+      // mid-drag, even though position tracking stayed correct; see the
+      // physics audit's Finding 5). Sleep is only interrupted by
+      // reactions that explicitly opt in via interruptsSleep.
+      if (runtime.behavior === 'dragged') return
+      if (runtime.behavior === 'sleep' && !reaction.interruptsSleep) return
       // Reaction dispatch: respect priority + cooldown (handled in stimuli.ts);
       // here we just force the behavior.
       const anim = reaction.anim as AnimName
@@ -156,7 +165,7 @@
       runtime.reactAnim = anim
       forceBehavior(runtime, id, { anim, durationMs: reaction.durationMs })
       if (reaction.bubble) {
-        runtime.bubble = reaction.bubble
+        runtime.bubbleText = reaction.bubble
         runtime.bubbleUntil = performance.now() + reaction.durationMs
       }
       if (reaction.effect) reaction.effect()
@@ -180,9 +189,13 @@
 
 <div bind:this={host} class="pointer-events-none absolute inset-0 z-[45]">
   <Mascot
-    {runtime}
+    bind:runtime
     onContextMenu={openMenu}
     onPet={onPet}
+    onRequestName={() => {
+      nameDialogMode = 'hatch'
+      nameDialogOpen = true
+    }}
   />
 </div>