feat(desktop): 目标上方浮动情境提示

新增 FloatingPrompt 纯布局模块（含 measureWidth 与 PixelText 等宽规则）：短提示锚定在唯一目标头顶上方，水平居中并钳制在视口内，避开左下 HUD 带（height-160）与右上状态条带（宽度 248）；沿用现有 CJK 图集字体路径，不新造字形；对话/需求面板与菜单打开时不显示（复用 worldInputAllowed 判定与渲染门）。回归测试覆盖 1280x720/1920x1080 五个极限锚点、宽度测量、面板开启时提示为空且禁用世界输入。

1 files changed, 13 insertions, 0 deletions

diff --git a/src/LivingVillage.Desktop/Game.fs b/src/LivingVillage.Desktop/Game.fs
index 4720008..1db5c3d 100644
--- a/src/LivingVillage.Desktop/Game.fs
+++ b/src/LivingVillage.Desktop/Game.fs
@@ -666,6 +666,19 @@ type LivingVillageGame() as this =
                 let spec = VillageArt.npcSpriteSpecAtTarget npc.Id npc.Pos npc.Mind.Target world.Tick
                 VillageArt.drawCharacter spriteBatch artTextures camera npc.Pos spec profile.WorldTint
         spriteBatch.End()
+
+        // Contextual floating prompt over the unique target; same CJK atlas font path as the HUD.
+        if m5View.Panel = M5Panel.WorldPanel && menu.Page = Playing then
+            match m5View.Prompt, m5View.PromptTargetPos with
+            | Some text, Some targetPos ->
+                let scale = 2
+                let rect = FloatingPrompt.layout viewport.Width viewport.Height targetPos.X targetPos.Y camera.X camera.Y scale text
+                spriteBatch.Begin()
+                spriteBatch.Draw(pixel, Rectangle(rect.X - 6, rect.Y - 5, rect.Width + 12, rect.Height + 8), Color(15, 19, 25, 200))
+                spriteBatch.Draw(pixel, Rectangle(rect.X - 6, rect.Y - 5, rect.Width + 12, 2), Color(92, 180, 190))
+                PixelText.draw spriteBatch pixel cjkAtlas rect.X rect.Y scale (Color(240, 250, 240)) text
+                spriteBatch.End()
+            | _ -> ()
         this.DrawM5Overlay()
 
     member private this.DrawM5Overlay() =