fix(world): restore portal and distant use lifecycles

src/AcDream.App/Input/LocalPlayerRuntimeState.cs

@@ -53,7 +53,9 @@ internal sealed class LocalPlayerControllerSlot
     /// and completes StopCompletely, so its MotionDone relay must reach the
     /// candidate interpreter before the complete controller is published.
     /// </summary>
-    public IDisposable BeginMotionPreparation(PlayerMovementController controller)
+    public IDisposable BeginMotionPreparation(
+        PlayerMovementController controller,
+        Action? drainPriorAnimationQueue = null)
     {
         ArgumentNullException.ThrowIfNull(controller);
         if (_preparingMotionOwner is not null)
@@ -62,6 +64,12 @@ internal sealed class LocalPlayerControllerSlot
                 "A local player motion owner is already being prepared.");
         }
 
+        // The live PartArray exists before the local player controller. Drain
+        // any animation completions produced under that prior ownership while
+        // they still resolve to the prior (or null) interpreter. Publishing
+        // the fresh interpreter first would let those old callbacks pop its
+        // new pending_motions queue and leave an unmatched Ready sentinel.
+        drainPriorAnimationQueue?.Invoke();
         _preparingMotionOwner = controller;
         return new MotionPreparation(this, controller);
     }