fix(motion): restore retail object manager order

Process animation completion at the retail process_hooks boundary, then run targeting, movement, PartArray completion, and PositionManager in the named UpdateObjectInternal order for local, remote, hidden, and position-less animated objects. Retire TS-42 with deterministic conformance coverage.\n\nCo-authored-by: OpenAI Codex <codex@openai.com>

tests/AcDream.App.Tests/Physics/RemotePhysicsUpdaterTests.cs

@@ -56,6 +56,35 @@ public sealed class RemotePhysicsUpdaterTests
         Assert.Equal(entity.Position, root.Translation);
     }
 
+    [Fact]
+    public void TickHidden_RunsPartArrayManagerTailWithoutAdvancingSequence()
+    {
+        var updater = new RemotePhysicsUpdater(
+            new PhysicsEngine(),
+            (_, _) => (0.48f, 1.835f),
+            (_, _, _, _) => { });
+        var motion = new GameWindow.RemoteMotion();
+        motion.Body.Orientation = Quaternion.Identity;
+        var entity = new WorldEntity
+        {
+            Id = 2u,
+            ServerGuid = 0x70000002u,
+            SourceGfxObjOrSetupId = 0x02000001u,
+            Position = Vector3.Zero,
+            Rotation = Quaternion.Identity,
+            MeshRefs = Array.Empty<MeshRef>(),
+        };
+        int partArrayTailCalls = 0;
+
+        updater.TickHidden(
+            motion,
+            entity,
+            0.1f,
+            () => partArrayTailCalls++);
+
+        Assert.Equal(1, partArrayTailCalls);
+    }
+
     [Fact]
     public void TickHidden_CrossCellCommitUpdatesCanonicalCellBeforeUnhide()
     {