fix: set the ghost owner before OnNetworkSpawn

- The ghost owner is now assigned right after SetupOnSpawn, so OnNetworkSpawn sees the same owner on the
  NetworkObject and its ghost. The interop test records the ghost owner in OnNetworkSpawn and asserts it.
- NetworkVariableReadDuringPredictionIsNotTickAligned asserts that a re-simulated tick reads a different value
  than its first prediction, rather than counting reads before the stamp tick.
- NetworkShowThenClientDisconnects is only ignored for UnifiedServer, the fixture where the scene migration
  failure occurs.

Author: NoelStephensUnity

com.unity.netcode.gameobjects/Runtime/Spawning/NetworkSpawnManager.cs

@@ -1183,7 +1183,6 @@ internal bool AuthorityLocalSpawn([NotNull] NetworkObject networkObject, ulong n
             if (networkObject.HasGhost)
             {
                 networkObject.NetworkObjectBridge.NetworkObjectId.Value = networkObject.NetworkObjectId;
-                networkObject.NetworkObjectBridge.UpdateGhostOwner(NetworkManager, networkObject.OwnerClientId);
             }
 #endif
 
@@ -1309,6 +1308,13 @@ internal bool SpawnNetworkObjectLocallyCommon(NetworkObject networkObject, ulong
             }
 
             networkObject.SetupOnSpawn(networkId, playerObject, ownerClientId, destroyWithScene);
+#if UNIFIED_NETCODE
+            // Before OnNetworkSpawn, so owner-specific initialization sees the ghost owner too.
+            if (networkObject.HasGhost)
+            {
+                networkObject.NetworkObjectBridge.UpdateGhostOwner(NetworkManager, ownerClientId);
+            }
+#endif
 
             SpawnedObjects.Add(networkObject.NetworkObjectId, networkObject);
             SpawnedObjectsList.Add(networkObject);

com.unity.netcode.gameobjects/Tests/Runtime/NetworkObject/NetworkObjectDontDestroyWithOwnerTests.cs

@@ -290,7 +290,7 @@ public IEnumerator DontDestroyWithOwnerTest([Values] ParentedPass parentedPass)
         public IEnumerator NetworkShowThenClientDisconnects()
         {
 #if UNIFIED_NETCODE
-            if (m_AllPrefabsAsHybrid)
+            if (m_AllPrefabsAsHybrid && !m_UseHost)
             {
                 Assert.Ignore("A scene migration update can reach a client before the hybrid object's ghost has spawned there.");
             }

com.unity.netcode.gameobjects/Tests/Runtime/Unified/HybridInteropTests.cs

@@ -155,10 +155,13 @@ internal class HybridInteropNetworkBehaviour : NetworkBehaviour
         public int OwnerWrittenTickChanges;
         public int OwnerWrittenTickDecreases;
         public bool GhostWasPredictedOnSpawn;
+        public NetworkId GhostOwnerOnSpawn;
 
         public override void OnNetworkSpawn()
         {
-            GhostWasPredictedOnSpawn = GetComponent<GhostObject>().IsPredictedGhost;
+            var ghost = GetComponent<GhostObject>();
+            GhostWasPredictedOnSpawn = ghost.IsPredictedGhost;
+            GhostOwnerOnSpawn = ghost.OwnerNetworkId;
             OwnerWrittenTick.OnValueChanged += OnOwnerWrittenTickChanged;
         }
 
@@ -242,8 +245,10 @@ protected override IEnumerator OnServerAndClientsConnected()
         {
             var client = m_ClientNetworkManagers[0];
             m_ServerInstance = SpawnObject(m_InteropPrefab, client).GetComponent<NetworkObject>();
-            Assert.AreEqual(client.NetcodeWorld.LocalConnection.NetworkId, m_ServerInstance.GetComponent<GhostObject>().OwnerNetworkId,
-                "Spawning with an NGO owner did not set the ghost owner!");
+            var clientNetworkId = client.NetcodeWorld.LocalConnection.NetworkId;
+            Assert.AreEqual(clientNetworkId, m_ServerInstance.GetComponent<GhostObject>().OwnerNetworkId, "Spawning with an NGO owner did not set the ghost owner!");
+            Assert.AreEqual(clientNetworkId, m_ServerInstance.GetComponent<HybridInteropNetworkBehaviour>().GhostOwnerOnSpawn,
+                "The ghost owner was not set yet when OnNetworkSpawn was invoked!");
             yield return WaitForSpawnedOnAllOrTimeOut(m_ServerInstance);
             AssertOnTimeout($"Timed out waiting for {m_ServerInstance.name} to spawn on all clients!");
             m_ClientInstance = client.SpawnManager.SpawnedObjects[m_ServerInstance.NetworkObjectId];
@@ -300,14 +305,14 @@ public IEnumerator NgoRpcToUnifiedRemoteToNgoRpc()
         }
 
         /// <summary>
-        /// A NetworkVariable is not rolled back: prediction of a tick before the value's stamp still reads the new value.
+        /// A NetworkVariable is not rolled back: re-simulating a tick can read a different value than its first prediction did.
         /// </summary>
         [UnityTest]
         public IEnumerator NetworkVariableReadDuringPredictionIsNotTickAligned()
         {
             yield return RecordAcrossStampedValueChange();
             var clientGhost = m_ClientInstance.GetComponent<HybridInteropGhost>();
-            Assert.Greater(clientGhost.EarlyReadsOfNewValue, 0, "Expected prediction of ticks before the stamp to read the new value.");
+            Assert.Greater(clientGhost.InconsistentRawTicks, 0, "Expected a re-simulated tick to read a different value than its first prediction.");
         }
 
         /// <summary>