Mark the last item stored in storage for smart-equip (#22236)

* mark the last item stored in grid inventory

* shift

Content.Client/UserInterface/Systems/Storage/Controls/StorageContainer.cs

@@ -249,6 +249,7 @@ public sealed class StorageContainer : BaseWindow
 
         var boundingGrid = storageComp.Grid.GetBoundingBox();
         var size = _emptyTexture!.Size * 2;
+        var lastEntity = storageComp.Container.ContainedEntities.LastOrDefault();
 
         //todo. at some point, we may want to only rebuild the pieces that have actually received new data.
 
@@ -278,6 +279,7 @@ public sealed class StorageContainer : BaseWindow
                         var gridPiece = new ItemGridPiece((itemEnt, itemEntComponent), item.Value, _entity)
                         {
                             MinSize = size,
+                            Marked = itemEnt == lastEntity
                         };
                         gridPiece.OnPiecePressed += OnPiecePressed;
                         gridPiece.OnPieceUnpressed += OnPieceUnpressed;