fix(items): complete retail corpse looting feedback

Route corpse Use through the shared ItemHolder policy so Stuck corpses open instead of being sent as pickup requests. Restore the framed, horizontally resizable external-container strip and use a compact initial width. Port retail's target-list pending item projection so loot is marked in the chosen inventory slot without changing canonical ownership before the server confirms.

Co-authored-by: OpenAI Codex <codex@openai.com>

src/AcDream.App/UI/RetailUiRuntime.cs

@@ -1640,20 +1640,7 @@ public sealed class RetailUiRuntime : IDisposable
             Host.Root,
             root,
             _bindings.Assets.ResolveSprite,
-            new RetailWindowFrame.Options
-            {
-                WindowName = WindowNames.ExternalContainer,
-                Chrome = RetailWindowChrome.Imported,
-                Left = root.Left,
-                Top = root.Top,
-                ContentWidth = root.Width,
-                ContentHeight = root.Height,
-                Visible = false,
-                Draggable = false,
-                Resizable = false,
-                ResizeX = false,
-                ResizeY = false,
-            });
+            ExternalContainerController.CreateWindowOptions(root));
 
         uint contentsEmpty;
         uint containerEmpty;