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>

tests/AcDream.App.Tests/UI/Layout/ExternalContainerControllerTests.cs

@@ -14,6 +14,40 @@ public sealed class ExternalContainerControllerTests
 
     private sealed class TestElement : UiElement { }
 
+    [Fact]
+    public void WindowPolicy_AddsOuterFrameAndAllowsHorizontalResize()
+    {
+        var screen = new UiRoot { Width = 1280f, Height = 720f };
+        var root = new TestElement
+        {
+            Left = 0f,
+            Top = 400f,
+            Width = 800f,
+            Height = 110f,
+        };
+        RetailWindowFrame.Options options =
+            ExternalContainerController.CreateWindowOptions(root);
+
+        RetailWindowHandle handle = RetailWindowFrame.Mount(
+            screen,
+            root,
+            static _ => (0u, 0, 0),
+            options);
+
+        var frame = Assert.IsType<UiNineSlicePanel>(handle.OuterFrame);
+        Assert.Equal(710f, frame.Width);
+        Assert.Equal(120f, frame.Height);
+        Assert.Equal(170f, frame.MinWidth);
+        Assert.True(frame.Draggable);
+        Assert.True(frame.Resizable);
+        Assert.True(frame.ResizeX);
+        Assert.False(frame.ResizeY);
+        Assert.Equal(ResizeEdges.Left | ResizeEdges.Right, frame.ResizableEdges);
+        Assert.True(frame.ConstrainResizeToParent);
+        Assert.False(frame.DrawCenterFill);
+        Assert.Equal(700f, root.Width);
+    }
+
     private sealed class Harness : IDisposable
     {
         public readonly ExternalContainerState State = new();

tests/AcDream.App.Tests/UI/Layout/InventoryControllerTests.cs

@@ -627,6 +627,68 @@ public class InventoryControllerTests
         Assert.Equal(Player, objects.Get(0xFFFFu)!.ContainerId);  // moved locally (instant)
     }
 
+    [Fact]
+    public void LootDrop_InsertsWaitingProjectionAtChosenSlotUntilServerConfirms()
+    {
+        const uint chest = 0x70000001u;
+        const uint loot = 0x70000002u;
+        var (layout, grid, _, _, _, _, _, _) = BuildLayout();
+        var objects = new ClientObjectTable();
+        SeedContained(objects, 0xAu, Player, slot: 0);
+        SeedContained(objects, 0xBu, Player, slot: 1);
+        SeedContained(objects, loot, chest, slot: 0, type: ItemType.Misc);
+        var selection = new SelectionState();
+        selection.Select(loot, SelectionChangeSource.ExternalContainer);
+        var puts = new List<(uint item, uint container, int placement)>();
+        using var ctrl = Bind(layout, objects, puts: puts, selection: selection);
+        var source = new UiItemSlot { SourceKind = ItemDragSource.Ground };
+        source.SetItem(loot, 0u);
+        var payload = new ItemDragPayload(loot, ItemDragSource.Ground, 0, source);
+
+        ctrl.HandleDropRelease(grid, grid.GetItem(1)!, payload);
+
+        Assert.Equal(new[] { (loot, Player, 1) }, puts);
+        Assert.Equal(chest, objects.Get(loot)!.ContainerId);
+        Assert.Equal(loot, grid.GetItem(1)!.ItemId);
+        Assert.True(grid.GetItem(1)!.WaitingVisual);
+        Assert.True(grid.GetItem(1)!.Selected);
+        Assert.Equal(0xBu, grid.GetItem(2)!.ItemId);
+
+        objects.ApplyConfirmedServerMove(loot, Player, 0u, newSlot: 1);
+
+        UiItemSlot confirmed = Enumerable.Range(0, grid.GetNumUIItems())
+            .Select(i => grid.GetItem(i)!)
+            .Single(cell => cell.ItemId == loot);
+        Assert.False(confirmed.WaitingVisual);
+        Assert.Equal(Player, objects.Get(loot)!.ContainerId);
+    }
+
+    [Fact]
+    public void LootDrop_ServerFailureRemovesOnlyThePendingProjection()
+    {
+        const uint chest = 0x70000001u;
+        const uint loot = 0x70000002u;
+        var (layout, grid, _, _, _, _, _, _) = BuildLayout();
+        var objects = new ClientObjectTable();
+        SeedContained(objects, 0xAu, Player, slot: 0);
+        SeedContained(objects, loot, chest, slot: 0, type: ItemType.Misc);
+        var puts = new List<(uint item, uint container, int placement)>();
+        using var ctrl = Bind(layout, objects, puts: puts);
+        var source = new UiItemSlot { SourceKind = ItemDragSource.Ground };
+        source.SetItem(loot, 0u);
+        var payload = new ItemDragPayload(loot, ItemDragSource.Ground, 0, source);
+
+        ctrl.HandleDropRelease(grid, grid.GetItem(1)!, payload);
+        Assert.Equal(loot, grid.GetItem(1)!.ItemId);
+
+        objects.RejectMove(loot, weenieError: 0x29u);
+
+        Assert.DoesNotContain(
+            Enumerable.Range(0, grid.GetNumUIItems()).Select(i => grid.GetItem(i)!.ItemId),
+            id => id == loot);
+        Assert.Equal(chest, objects.Get(loot)!.ContainerId);
+    }
+
     [Fact]
     public void Drop_onEmptyGridCell_appendsToFirstEmpty()
     {