feat(vfx): port retail hidden and teleport presentation

Preserve canonical live-object ownership across Hidden transitions and remote teleport placement so effects, collision, streaming, and targeting remain synchronized.

src/AcDream.Core/Physics/Motion/TargetManager.cs

@@ -297,4 +297,22 @@ public sealed class TargetManager
         foreach (var voyeur in _voyeurTable.Values.ToList())
             SendVoyeurUpdate(voyeur, _host.Position, status);
     }
+
+    /// <summary>
+    /// Broadcasts a terminal availability event and drops the watched-role
+    /// subscriptions after delivery. Retail normally removes the object from
+    /// cell lookup before its watchers process the event; clearing the local
+    /// table explicitly preserves that lifecycle boundary when the App uses
+    /// the target fan-out as the temporary bridge for an unavailable object.
+    /// The object's own watcher role (<see cref="TargetInfo"/>) is untouched.
+    /// </summary>
+    public void NotifyVoyeurOfEventAndClear(TargetStatus status)
+    {
+        if (_voyeurTable == null)
+            return;
+
+        foreach (var voyeur in _voyeurTable.Values.ToList())
+            SendVoyeurUpdate(voyeur, _host.Position, status);
+        _voyeurTable.Clear();
+    }
 }