General storage fixes (#34845)

* Fix storage stars

* Fix some more storage bugs

- Fix positions not saving.
- Fix the 1-tick delay between parent and child storage UIs opening / closing.
- Fix BackButton being visible sometimes when it shouldn't be.

* milon is a furry

Content.Client/Storage/Systems/StorageSystem.cs

@@ -19,6 +19,8 @@ public sealed class StorageSystem : SharedStorageSystem
 
     private Dictionary<EntityUid, ItemStorageLocation> _oldStoredItems = new();
 
+    private List<(StorageBoundUserInterface Bui, bool Value)> _queuedBuis = new();
+
     public override void Initialize()
     {
         base.Initialize();
@@ -72,7 +74,7 @@ public sealed class StorageSystem : SharedStorageSystem
             if (NestedStorage && player != null && ContainerSystem.TryGetContainingContainer((uid, null, null), out var container) &&
                 UI.TryGetOpenUi<StorageBoundUserInterface>(container.Owner, StorageComponent.StorageUiKey.Key, out var containerBui))
             {
-                containerBui.Hide();
+                _queuedBuis.Add((containerBui, false));
             }
         }
     }
@@ -89,7 +91,7 @@ public sealed class StorageSystem : SharedStorageSystem
     {
         if (UI.TryGetOpenUi<StorageBoundUserInterface>(uid, StorageComponent.StorageUiKey.Key, out var storageBui))
         {
-            storageBui.Hide();
+            _queuedBuis.Add((storageBui, false));
         }
     }
 
@@ -97,7 +99,7 @@ public sealed class StorageSystem : SharedStorageSystem
     {
         if (UI.TryGetOpenUi<StorageBoundUserInterface>(uid, StorageComponent.StorageUiKey.Key, out var storageBui))
         {
-            storageBui.Show();
+            _queuedBuis.Add((storageBui, true));
         }
     }
 
@@ -152,4 +154,30 @@ public sealed class StorageSystem : SharedStorageSystem
             }
         }
     }
+
+    public override void Update(float frameTime)
+    {
+        base.Update(frameTime);
+
+        if (!_timing.IsFirstTimePredicted)
+        {
+            return;
+        }
+
+        // This update loop exists just to synchronize with UISystem and avoid 1-tick delays.
+        // If deferred opens / closes ever get removed you can dump this.
+        foreach (var (bui, open) in _queuedBuis)
+        {
+            if (open)
+            {
+                bui.Show();
+            }
+            else
+            {
+                bui.Hide();
+            }
+        }
+
+        _queuedBuis.Clear();
+    }
 }