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.

tests/AcDream.Core.Tests/Physics/InitialPlacementOverlapTests.cs

@@ -50,6 +50,9 @@ public sealed class InitialPlacementOverlapTests
             movingEntityId: PlayerId);
 
         Assert.True(result.Ok);
+        Assert.True(result.InContact);
+        Assert.True(result.OnWalkable);
+        Assert.Equal(Cell, result.ContactPlaneCellId);
         Assert.NotEqual(savedFeet, result.Position);
         float centerDistance = Vector3.Distance(
             result.Position + new Vector3(0f, 0f, Radius),