test(desktop): P38 HUD 图标布局与确定性回归

新增 P38HudIconTests（4 例）：五段图标唯一且 7x7 点阵良构、段宽=图标+间隙+文本且
不重叠/在 1280 内、段与布局确定、昼夜底色半透明且覆盖图标与文本。

1 files changed, 71 insertions, 0 deletions

diff --git a/src/LivingVillage.Desktop.Tests/P38HudIconTests.fs b/src/LivingVillage.Desktop.Tests/P38HudIconTests.fs
new file mode 100644
index 0000000..72885fb
--- /dev/null
+++ b/src/LivingVillage.Desktop.Tests/P38HudIconTests.fs
@@ -0,0 +1,71 @@
+namespace LivingVillage.Desktop.Tests
+
+open Microsoft.VisualStudio.TestTools.UnitTesting
+open LivingVillage.Kernel
+open LivingVillage.Kernel.Sim
+open LivingVillage.Desktop
+
+/// P38 界面升级切片：顶部常驻 HUD 图标化（时段/时间/倍速/体力/钱币）的布局与确定性回归。
+[<TestClass>]
+type P38HudIconTests () =
+
+    let world = Sim.initialWorldN 42UL 4
+    let control = SimulationControl.initial
+    let segments = HudLayout.segments world control
+
+    [<TestMethod>]
+    member _.EveryHudSegmentCarriesAWellFormedDistinctIcon () =
+        let expected =
+            [ "时段", HudLayout.PeriodIcon
+              "时间", HudLayout.ClockIcon
+              "倍速", HudLayout.SpeedIcon
+              "体力", HudLayout.EnergyIcon
+              "钱币", HudLayout.MoneyIcon ]
+        Assert.AreEqual<string list>(expected |> List.map fst, segments |> List.map (fun segment -> segment.Label))
+        Assert.AreEqual<HudLayout.HudIcon list>(expected |> List.map snd, segments |> List.map (fun segment -> segment.Icon))
+        for segment in segments do
+            let rows = HudLayout.iconRows segment.Icon
+            Assert.IsTrue(rows.Length = HudLayout.iconGrid, sprintf "%s 图标行数" segment.Label)
+            for row in rows do
+                Assert.IsTrue(row.Length = HudLayout.iconGrid, sprintf "%s 图标行宽" segment.Label)
+            Assert.IsTrue(rows |> List.exists (fun row -> row.Contains "1"), sprintf "%s 图标必须有实心像素" segment.Label)
+        let distinct = segments |> List.map (fun segment -> segment.Icon) |> List.distinct |> List.length
+        Assert.IsTrue(segments.Length = distinct, "每个常驻段图标应互不相同")
+
+    [<TestMethod>]
+    member _.HudLayoutReservesIconThenTextAndFitsTheStrip () =
+        let placed = HudLayout.layout segments
+        Assert.AreEqual<int>(segments.Length, placed.Length)
+        let (firstX, _, _) = List.head placed
+        Assert.AreEqual<int>(HudLayout.paddingX, firstX)
+        for (x, width, segment) in placed do
+            let textWidth = FloatingPrompt.measureWidth (HudLayout.segmentText segment) HudLayout.textScale
+            Assert.AreEqual<int>(HudLayout.iconWidth + HudLayout.iconGap + textWidth, width)
+            // 图标与文本都必须落在段宽内。
+            Assert.IsTrue(x + HudLayout.iconWidth <= x + width, "图标越出段宽")
+            Assert.IsTrue(HudLayout.textOrigin x + textWidth <= x + width, "文本越出段宽")
+            Assert.IsTrue(HudLayout.iconHeight <= HudLayout.barHeight, "图标必须放进窄条")
+        placed
+        |> List.pairwise
+        |> List.iter (fun ((x1, w1, _), (x2, _, _)) ->
+            Assert.IsTrue(x2 >= x1 + w1, sprintf "段重叠：%d+%d vs %d" x1 w1 x2))
+        let (lastX, lastWidth, _) = List.last placed
+        Assert.IsTrue(lastX + lastWidth <= 1280, "最后一段必须留在 1280 视口内")
+
+    [<TestMethod>]
+    member _.HudSegmentsAndLayoutAreDeterministic () =
+        Assert.AreEqual<HudLayout.Segment list>(segments, HudLayout.segments world control)
+        Assert.AreEqual<(int * int * HudLayout.Segment) list>(HudLayout.layout segments, HudLayout.layout segments)
+        for segment in segments do
+            Assert.AreEqual<string list>(HudLayout.iconRows segment.Icon, HudLayout.iconRows segment.Icon)
+
+    [<TestMethod>]
+    member _.HudBackdropCoversIconAndTextInBothPeriods () =
+        for mode in [ Day; Night ] do
+            let palette = HudLayout.palette mode
+            Assert.IsTrue(palette.SegmentBackdrop.A > 0uy && palette.SegmentBackdrop.A < 255uy, "底色必须半透明")
+        for (x, width, _) in HudLayout.layout segments do
+            let rect = HudLayout.segmentBackdrop x width
+            Assert.IsTrue(rect.X <= x, "底色未覆盖图标左沿")
+            Assert.IsTrue(rect.X + rect.Width >= HudLayout.textOrigin x, "底色未覆盖文本区")
+            Assert.IsTrue(rect.Y >= 0 && rect.Y + rect.Height <= HudLayout.barHeight, "底色必须留在窄条内")