fix(ui): port retail window control feedback

Map synthetic move and resize affordances to the exact DAT cursors, make chat top chrome movable, and replace stale primary-panel height caps with a dynamic screen-edge constraint. This keeps the retained wrapper adaptation aligned with retail Dragbar/Resizebar behavior.

src/AcDream.App/UI/RetailCursorCatalog.cs

@@ -1,6 +1,11 @@
 namespace AcDream.App.UI;
 
-/// <summary>Retail global cursor enum metadata used outside LayoutDesc widget states.</summary>
+/// <summary>
+/// Retail cursor metadata used outside ordinary LayoutDesc widget-state lookup.
+/// Global cursors resolve through enum table 6; synthetic retained-window control
+/// regions use the exact direct cursor media authored on retail Dragbar/Resizebar
+/// elements.
+/// </summary>
 internal static class RetailCursorCatalog
 {
     public const uint CursorEnumTable = 6;
@@ -32,6 +37,31 @@ internal static class RetailCursorCatalog
 
         return spec.IsValid;
     }
+
+    /// <summary>
+    /// Direct <c>MD_Data_Cursor</c> surfaces authored on retail Type-2 Dragbar and
+    /// Type-9 Resizebar controls. The retained wrapper border has no LayoutDesc
+    /// element of its own, so it uses the same media through this shared seam.
+    /// </summary>
+    public static bool TryGetWindowControlCursor(
+        CursorFeedbackKind kind,
+        out UiCursorMedia cursor)
+    {
+        // MediaMachine::Update_Cursor @ 0x00465A80 installs these element-local
+        // cursor DIDs; UIElementManager::CheckCursor @ 0x0045ABF0 preserves the
+        // captured Dragbar/Resizebar cursor for the complete operation.
+        cursor = kind switch
+        {
+            CursorFeedbackKind.WindowMove => new UiCursorMedia(0x06006119u, 16, 16),
+            CursorFeedbackKind.ResizeHorizontal => new UiCursorMedia(0x06006128u, 16, 16),
+            CursorFeedbackKind.ResizeVertical => new UiCursorMedia(0x06005E66u, 16, 16),
+            CursorFeedbackKind.ResizeDiagonalNwse => new UiCursorMedia(0x06006126u, 16, 16),
+            CursorFeedbackKind.ResizeDiagonalNesw => new UiCursorMedia(0x06006127u, 16, 16),
+            _ => default,
+        };
+
+        return cursor.IsValid;
+    }
 }
 
 internal readonly record struct RetailCursorSpec(uint EnumId, int HotspotX, int HotspotY)