fix(desktop): 标题菜单光标与文字分列不再叠印

根因：页面标题行（panelY+24）与首行内容（MenuTopY）同为 y=320 造成两串文字叠印。修复：TitleScreen 布局新增 HeadingY/FirstItemY 分层与独立光标列（CursorX/CursorWidth/TextX），selectionRects 纯函数返回光标与文字矩形，回归测试断言逐行矩形不相交且标题行净空≥32px；渲染改为光标、文字分别绘制。

1 files changed, 16 insertions, 0 deletions

diff --git a/src/LivingVillage.Desktop.Tests/PrototypeTests.fs b/src/LivingVillage.Desktop.Tests/PrototypeTests.fs
index 524573f..c85287f 100644
--- a/src/LivingVillage.Desktop.Tests/PrototypeTests.fs
+++ b/src/LivingVillage.Desktop.Tests/PrototypeTests.fs
@@ -246,6 +246,22 @@ type PrototypeTests () =
         Assert.IsTrue(ChineseText.requiredUiLabels |> List.contains "精力")
 
     [<TestMethod>]
+    member _.TitleScreenSelectionCursorAndLabelNeverOverprint () =
+        let layout = TitleScreen.layout 1280 720
+
+        // Heading must sit fully above the first menu row (no same-line overprint).
+        Assert.IsTrue(layout.FirstItemY - layout.HeadingY >= 32, sprintf "heading clearance %d" (layout.FirstItemY - layout.HeadingY))
+
+        // Every menu row: cursor rectangle and label rectangle must be disjoint.
+        for rowIndex in 0 .. 5 do
+            let cursor, label = TitleScreen.selectionRects layout rowIndex
+            Assert.IsTrue(TitleScreen.rectsDisjoint cursor label, sprintf "row %d cursor overlaps label" rowIndex)
+            Assert.AreEqual<int>(cursor.Y, label.Y)
+
+        // Cursor column leaves real clearance: label starts beyond cursor + margin.
+        Assert.IsTrue(layout.TextX >= layout.CursorX + layout.CursorWidth)
+
+    [<TestMethod>]
     member _.TitleScreenLayoutIsDeterministicAndLayered () =
         let first = TitleScreen.layout 1280 720
         let second = TitleScreen.layout 1280 720