fix #378: Config-tab dropdown menus render bare with no popup chrome

Root cause: DatWidgetFactory builds Config-tab Type-0x10000038 menu
leaves as bare UiMenu instances (matching the vendor/chat channel menu
pattern), but unlike those two controllers, ConfigOptionsPageController
never wired the menu's sprite/font/geometry properties after Bind — so
every dropdown rendered as plain text with no button well, no arrow
cap, and opened no popup on click (#374's fix only corrected click
ROUTING, not the missing chrome).

Fix: ConfigOptionsPageController.ApplyMenuChrome wires every Config-tab
menu row with the SAME retail sprite ids VendorUiController/
ChatWindowController's channel menu already use for this shared popup
catalog (LayoutDesc 0x21000043), verified against the live DAT via
OptionsPanelLiveMountProbeTests' ProbeConfigMenuChrome/
ProbeConfigMenuPopupChrome probes. Regressed by
ConfigOptionsPageControllerTests.MenuRow_SoundFeatures_OpensAndSelects
ThroughRealHitPath_UsingAuthoredPopupGeometry, which drives the real
click-to-open + item-pick path through the authored popup geometry.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

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

@@ -320,6 +320,23 @@ public sealed class ConfigOptionsPageControllerTests
         return (controller, fakeBindings, bound);
     }
 
+    /// <summary>Every built <see cref="UiMenu"/> under a subtree, in
+    /// document (build) order — the same recursive-walk shape
+    /// <c>ChatOptionsPageControllerTests.CollectScalarSliders</c> uses for
+    /// its own widget-type collection.</summary>
+    private static List<UiMenu> CollectMenus(UiElement root)
+    {
+        var found = new List<UiMenu>();
+        Walk(root, found);
+        return found;
+
+        static void Walk(UiElement node, List<UiMenu> acc)
+        {
+            if (node is UiMenu menu) acc.Add(menu);
+            foreach (UiElement child in node.Children) Walk(child, acc);
+        }
+    }
+
     [Fact]
     public void Bind_Succeeds_AndRegistersExactly30Rows()
     {
@@ -466,6 +483,87 @@ public sealed class ConfigOptionsPageControllerTests
         Assert.Equal(1, bindings.AudioSaves[^1].SoundFeatures);
     }
 
+    /// <summary>
+    /// #378 regression (2026-08-11, gate 4): before this fix, NOTHING wired
+    /// any Config-tab dropdown's chrome — every sprite id was 0, no arrow
+    /// cap, no popup. Drives the REAL <see cref="UiMenu"/> hit-test/pick
+    /// path <see cref="VendorUiControllerTests.CategoryMenu_OpensAndSelectsThroughRealHitPath_UsingAuthoredPopupGeometry"/>
+    /// already established for vendor's own dropdown — the SAME
+    /// authored popup catalog (LayoutDesc <c>0x21000043</c>) both dropdowns
+    /// derive from, byte-verified identical (see
+    /// <see cref="ConfigOptionsPageController.MenuChromeSprites"/>'s own
+    /// doc), so the SAME click-geometry formula applies.
+    /// </summary>
+    [Fact]
+    public void MenuRow_SoundFeatures_OpensAndSelectsThroughRealHitPath_UsingAuthoredPopupGeometry()
+    {
+        ImportedLayout layout = FixtureLoader.LoadOptionsPanelHost();
+        OptionsPanelController controller = OptionsPanelController.Bind(
+            layout,
+            new OptionsPanelController.Callbacks(
+                Toggle: () => { },
+                RequestExitToCharacterSelection: () => { },
+                ExitGame: () => { },
+                UseMouseTurningSettings: () => { },
+                DisplaySystemMessage: _ => { }))!;
+        var fakeBindings = new FakeBindings();
+        bool bound = ConfigOptionsPageController.Bind(
+            layout,
+            controller.ConfigPage,
+            MakeTemplateResolver(),
+            (_, _) => null,
+            fakeBindings.ToBindings(),
+            resolveSprite: _ => (1u, 8, 8));
+        Assert.True(bound);
+
+        var listBox = Assert.IsType<UiTemplateListBox>(
+            layout.FindElement(ConfigOptionsPageController.ListBoxElementId));
+        List<UiMenu> menus = CollectMenus(listBox);
+        Assert.Equal(8, menus.Count); // the 8 Config-tab dropdown rows
+        UiMenu soundFeatures = menus[0]; // build order matches Rows order — Sound Features first
+
+        // Wiring: without these UiMenu.OnDrawOverlay early-returns (nothing
+        // renders) and the button face never draws either — the bare-text
+        // symptom #378 reported.
+        Assert.NotNull(soundFeatures.SpriteResolve);
+        Assert.NotEqual(0u, soundFeatures.NormalSprite);
+        Assert.NotEqual(0u, soundFeatures.PressedSprite);
+        Assert.NotEqual(0u, soundFeatures.ItemNormalSprite);
+        Assert.NotEqual(0u, soundFeatures.ItemHighlightSprite);
+        Assert.NotEqual(0u, soundFeatures.ArrowCapClosedSprite);
+        Assert.NotEqual(0u, soundFeatures.ArrowCapOpenSprite);
+
+        // Geometry from the live-DAT-verified popup catalog (0x21000043) —
+        // see MenuChromeSprites' own doc.
+        Assert.True(soundFeatures.Scrollable);
+        Assert.Equal(6, soundFeatures.RowsPerColumn);
+        Assert.Equal(18f, soundFeatures.RowHeight);
+        Assert.Equal(100f, soundFeatures.ColumnWidth);
+        Assert.False(soundFeatures.OpenUpward); // no authored attribute 5 — absent defaults false
+
+        Assert.False(soundFeatures.IsOpen);
+
+        // Open via the real widget event path (button click).
+        Assert.True(soundFeatures.OnEvent(new UiEvent(0, soundFeatures, UiEventType.MouseDown, 0, 10, 5)));
+        Assert.True(soundFeatures.IsOpen);
+
+        // "Mono" is the SECOND choice (Stereo, then Mono) -> row index 1.
+        // Popup opens DOWNWARD (OpenUpward=false), so its top sits at the
+        // button's own bottom edge (ly = Height) — same formula
+        // VendorUiControllerTests already established for the identical
+        // popup catalog.
+        const int border = 5; // RetailChromeSprites.Border (UiMenu's private bevel thickness)
+        const int targetRow = 1;
+        float iy = targetRow * soundFeatures.RowHeight + soundFeatures.RowHeight / 2f;
+        float ly = soundFeatures.Height + iy + border;
+
+        Assert.True(soundFeatures.OnEvent(new UiEvent(0, soundFeatures, UiEventType.MouseDown, 0, 10, (int)ly)));
+
+        Assert.False(soundFeatures.IsOpen); // picking a row closes the popup
+        Assert.Equal(1, fakeBindings.Audio.SoundFeatures);
+        Assert.Equal(1, fakeBindings.AudioSaves[^1].SoundFeatures);
+    }
+
     [Fact]
     public void MenuRow_Resolution_IsStringBacked_AndWritesThroughDisplayBindings()
     {