fix(ui): match retail spell bar controls

Place favorite-bar arrows by their authored sides, import rollover and pressed media through the shared scrollbar, and preserve manual offsets across passive refreshes. Carry the mixed-parent DAT anchor chain to a fixed 18-cell favorite viewport so overflow controls and the Cast button remain inside the retail-sized combat frame.

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

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

@@ -7,6 +7,43 @@ public sealed class RetailWindowFrameTests
 {
     private static (uint, int, int) NoTex(uint _) => (0u, 0, 0);
 
+    [Theory]
+    [InlineData(9, 459f, 288f)]
+    [InlineData(13, 587f, 416f)]
+    [InlineData(18, 747f, 576f)]
+    public void CombatRoot_FitsRequestedFavoriteSlotCapacity(
+        int visibleSlots,
+        float expectedRootWidth,
+        float expectedListWidth)
+    {
+        ImportedLayout combat = LayoutImporter.Build(
+            FixtureLoader.LoadCombatInfos(), NoTex, datFont: null);
+
+        float width = RetailCombatLayout.FitFavoriteSlots(combat, visibleSlots);
+
+        Assert.Equal(expectedRootWidth, width);
+        Assert.Equal(expectedListWidth, combat.FindElement(
+            SpellcastingUiController.FavoriteListId)!.Width);
+    }
+
+    [Fact]
+    public void CombatRoot_EighteenSlotsKeepArrowsAndCastInsideFrame()
+    {
+        ImportedLayout combat = LayoutImporter.Build(
+            FixtureLoader.LoadCombatInfos(), NoTex, datFont: null);
+
+        RetailCombatLayout.FitFavoriteSlots(combat);
+
+        UiElement group = combat.FindElement(0x100000AAu)!;
+        UiElement scrollbar = combat.FindElement(SpellcastingUiController.FavoriteScrollbarId)!;
+        UiElement cast = combat.FindElement(SpellcastingUiController.CastButtonId)!;
+        Assert.Equal(747f, combat.Root.Width);
+        Assert.Equal((40f, 622f), (group.Left, group.Width));
+        Assert.Equal(622f, scrollbar.Width);
+        Assert.Equal((662f, 75f), (cast.Left, cast.Width));
+        Assert.Equal(737f, cast.Left + cast.Width);
+    }
+
     [Fact]
     public void ImportedChrome_MountsRootWithoutASecondFrame()
     {
@@ -41,6 +78,30 @@ public sealed class RetailWindowFrameTests
         Assert.Equal(40f, content.MinWidth);
     }
 
+    [Fact]
+    public void ImportedChrome_CanPreserveFixedHudDesktopAnchors()
+    {
+        var root = new UiRoot { Width = 1920, Height = 1080 };
+        var content = new UiPanel { Width = 1730, Height = 90 };
+
+        RetailWindowHandle handle = RetailWindowFrame.Mount(
+            root,
+            content,
+            NoTex,
+            new RetailWindowFrame.Options
+            {
+                WindowName = "combat",
+                Chrome = RetailWindowChrome.Imported,
+                Left = 0f,
+                Top = 980f,
+                OuterAnchors = AnchorEdges.Left | AnchorEdges.Bottom,
+            });
+
+        Assert.Equal(
+            AnchorEdges.Left | AnchorEdges.Bottom,
+            handle.OuterFrame.Anchors);
+    }
+
     [Fact]
     public void NineSlice_UsesCroppedContentAndDatHeightConstraints()
     {