fix: smooth persona hover transitions

Preserve the original reflection material while adding pointer inertia and a short exit hold. Retain the Rive pointer constraint through the fade and blend rapid re-entry to avoid abrupt changes.

Cover timing, re-entry, cancellation, renderer disposal and native Rive frames. The fade regression fails with the previous resource and passes with the updated resource.

src/shared/ai-elements/persona-hover-timing.json

@@ -0,0 +1,7 @@
+{
+  "enterMs": 150,
+  "followMs": 80,
+  "exitHoldMs": 100,
+  "exitMs": 600,
+  "blendMs": 100
+}