fix(ui): select items before drag mesh

Port ItemList_BeginDrag's select-before-waiting order so a direct press-drag shows the selection indicator on its first frame across inventory, paperdoll, and toolbar item lists.

Co-Authored-By: Codex <codex@openai.com>

src/AcDream.App/UI/Layout/InventoryController.cs

@@ -422,9 +422,15 @@ public sealed class InventoryController : IItemListDragHandler, IRetainedPanelCo
     }
 
     // ── IItemListDragHandler (B-Drag) — drop an item to move it (optimistic + wire) ──────────────
-    /// <summary>Inventory items do NOT lift-remove (unlike the toolbar): the item stays in its slot
-    /// while <see cref="UiItemSlot"/> reveals retail's waiting/ghosted mesh until release.</summary>
-    public void OnDragLift(UiItemList sourceList, UiItemSlot sourceCell, ItemDragPayload payload) { }
+    /// <summary>Retail ItemList_BeginDrag selects an unselected item before enabling its waiting
+    /// mesh. Inventory items do not lift-remove (unlike the toolbar): the item stays in its slot
+    /// until the server confirms the eventual drop.</summary>
+    public void OnDragLift(UiItemList sourceList, UiItemSlot sourceCell, ItemDragPayload payload)
+    {
+        // UIElement_ItemList::ItemList_BeginDrag @ 0x004E32D0.
+        if (payload.ObjId != 0 && _selection.SelectedObjectId != payload.ObjId)
+            _selection.Select(payload.ObjId, SelectionChangeSource.Inventory);
+    }
 
     /// <summary>Advisory neutral/accept/reject overlay. Shortcut aliases stay neutral; physical grid
     /// drops accept; a side-bag/main-pack drop rejects only when that container is known full.</summary>

src/AcDream.App/UI/Layout/PaperdollController.cs

@@ -283,9 +283,15 @@ public sealed class PaperdollController : IItemListDragHandler, IRetainedPanelCo
     }
 
     // ── IItemListDragHandler ──────────────────────────────────────────────────────────────────────
-    /// <summary>No-op: a wielded item stays put until the server confirms (same as the inventory grid,
-    /// unlike the toolbar's remove-on-lift). Unwield happens on DROP onto the pack grid — InventoryController.</summary>
-    public void OnDragLift(UiItemList sourceList, UiItemSlot sourceCell, ItemDragPayload payload) { }
+    /// <summary>Selects the wielded item before the waiting mesh appears. The item itself stays put
+    /// until the server confirms, like the inventory grid and unlike the toolbar's remove-on-lift.
+    /// Unwield happens on DROP onto the pack grid — InventoryController.</summary>
+    public void OnDragLift(UiItemList sourceList, UiItemSlot sourceCell, ItemDragPayload payload)
+    {
+        // UIElement_ItemList::ItemList_BeginDrag @ 0x004E32D0.
+        if (payload.ObjId != 0 && _selection.SelectedObjectId != payload.ObjId)
+            _selection.Select(payload.ObjId, SelectionChangeSource.Paperdoll);
+    }
 
     /// <summary>Accept iff the dragged item can be worn here (its ValidLocations intersects the slot mask).
     /// Retail: gmPaperDollUI::OnItemListDragOver (decomp 174302).</summary>

src/AcDream.App/UI/Layout/ToolbarController.cs

@@ -615,6 +615,11 @@ public sealed class ToolbarController : IItemListDragHandler, IRetainedPanelCont
     /// <inheritdoc/>
     public void OnDragLift(UiItemList sourceList, UiItemSlot sourceCell, ItemDragPayload payload)
     {
+        // UIElement_ItemList::ItemList_BeginDrag @ 0x004E32D0 selects first; the toolbar's
+        // RecvNotice_ItemListBeginDrag handler then removes the shortcut alias.
+        if (payload.ObjId != 0 && _selectedObjectId() != payload.ObjId)
+            _selectItem?.Invoke(payload.ObjId);
+
         // Retail RecvNotice_ItemListBeginDrag → RemoveShortcut (0x004bd930/0x004bd450): the lifted
         // shortcut leaves the bar (+ wire) the instant the drag starts; it's re-placed only on a
         // drop onto a slot. Off-bar release leaves it removed.

src/AcDream.App/UI/UiRoot.cs

@@ -757,9 +757,12 @@ public sealed class UiRoot : UiElement
         DragSource  = source;
         DragPayload = payload;
         _dragGhost  = source.GetDragGhost();   // snapshot NOW — the DragBegin handler may empty the source cell
-        source.SetDragSourceActive(true, payload);
         var e = new UiEvent(source.EventId, source, UiEventType.DragBegin, Payload: payload);
         source.OnEvent(in e);
+        // Retail UIElement_ItemList::ItemList_BeginDrag @ 0x004E32D0 selects an
+        // unselected item before enabling its waiting mesh. Keep that order so a
+        // press-drag shows the selection indicator on its very first frame.
+        source.SetDragSourceActive(true, payload);
     }
 
     private void UpdateDragHover(int x, int y)