feat(desktop): P36 情境提示取证钩子 LV_P36_SHOT

复用 sample 脚本走位/互动序列，在自然状态下抓 4 帧关键帧
（靠近→提示出现→对话层打开且世界交互被隔离→关闭走远提示消失）
并逐帧打印 panel/prompt/home 对照点，第 4 帧后退出。仅证据用，不影响默认玩法。

1 files changed, 49 insertions, 1 deletions

diff --git a/src/LivingVillage.Desktop/Game.fs b/src/LivingVillage.Desktop/Game.fs
index c68cf6a..c796953 100644
--- a/src/LivingVillage.Desktop/Game.fs
+++ b/src/LivingVillage.Desktop/Game.fs
@@ -96,7 +96,10 @@ type LivingVillageGame() as this =
 
     let autoplay = (Environment.GetEnvironmentVariable("LV_AUTOPLAY") = "1") || (Environment.GetEnvironmentVariable("LV_MAP_TOUR") = "1")
     let autoplayFlow = Environment.GetEnvironmentVariable("LV_AUTOPLAY_FLOW") = "1"
-    let sampleMode = Environment.GetEnvironmentVariable("LV_AUTOPLAY_SAMPLE") = "1"
+    // P36 证据钩子：复用 sample 脚本的走位/互动序列，但按状态抓 4 帧关键帧
+    // （靠近→提示出现→对话层打开且世界交互被隔离→关闭离开提示消失）后退出。
+    let p36ShotMode = Environment.GetEnvironmentVariable("LV_P36_SHOT") = "1"
+    let sampleMode = Environment.GetEnvironmentVariable("LV_AUTOPLAY_SAMPLE") = "1" || p36ShotMode
     let menuShotMode = Environment.GetEnvironmentVariable("LV_AUTOPLAY_MENU_SHOT") = "1"
     let daylightAutoplay = Environment.GetEnvironmentVariable("LV_AUTOPLAY_DAYLIGHT") = "1"
     let automated = autoplay || autoplayFlow
@@ -277,6 +280,7 @@ type LivingVillageGame() as this =
     let mutable flowStep = 0
     let mutable flowHold = 0
     let mutable sampleState = SampleScript.initial
+    let mutable p36Captured = Array.zeroCreate<bool> 4
     let mutable hudClock = 0L
     let mutable hudStatus = ""
     let mutable hudStatusAt = 0L
@@ -518,6 +522,48 @@ type LivingVillageGame() as this =
                     printfn (if nextState.TimedOut then "sample result=timeout" else "sample result=ok")
                     this.Exit()
 
+    /// P36 证据：在 sample 序列的自然状态下抓 4 帧，证明「情境提示」契约：
+    /// 1 靠近目标（进入 ApproachNpc）2 提示出现 3 对话层打开（浮动提示消失=世界交互被隔离）
+    /// 4 关闭并走远后提示消失。每帧打印 panel/prompt/home 对照点，第 4 帧后退出。
+    member private this.CaptureP36PromptShot () =
+        if p36ShotMode then
+            let save (index: int) (label: string) =
+                System.IO.Directory.CreateDirectory recordDirectory |> ignore
+                this.SaveBackBuffer(sprintf "%s/p36-prompt-approach-%d.png" recordDirectory index)
+                printfn
+                    "p36-shot=%s index=%d tick=%d pos=(%.0f,%.0f) panel=%s prompt=%s home=%A"
+                    label
+                    index
+                    world.Tick
+                    world.Avatar.Pos.X
+                    world.Avatar.Pos.Y
+                    (M5Interaction.panelName m5View)
+                    (m5View.Prompt |> Option.defaultValue "<none>")
+                    m5View.HomeMode
+            let stage = sampleState.Stage
+            // 第 4 帧必须已真正走远（超出所有村民的交谈范围）且提示消失，才能证明「离开即消失」。
+            let leaveMargin = Sim.chatRangePx + 24.0f
+            let outsideEveryRange =
+                world.Npcs
+                |> Array.forall (fun npc ->
+                    let dx = npc.Pos.X - world.Avatar.Pos.X
+                    let dy = npc.Pos.Y - world.Avatar.Pos.Y
+                    dx * dx + dy * dy > leaveMargin * leaveMargin)
+            if not p36Captured.[0] && stage = SampleScript.ApproachNpc then
+                p36Captured.[0] <- true
+                save 1 "approach"
+            elif not p36Captured.[1] && stage = SampleScript.ApproachNpc && m5View.Prompt.IsSome then
+                p36Captured.[1] <- true
+                save 2 "prompt"
+            elif not p36Captured.[2] && m5View.Panel = DialoguePanel && m5View.Menu.IsSome then
+                p36Captured.[2] <- true
+                save 3 "dialogue-isolated"
+            elif not p36Captured.[3] && stage = SampleScript.WalkAway && m5View.Prompt.IsNone && outsideEveryRange then
+                p36Captured.[3] <- true
+                save 4 "left"
+                printfn "p36-shot=done tick=%d" world.Tick
+                this.Exit()
+
     /// P16-FIX：菜单截图模式。停在开始界面，按确定性帧表向下切到「读档」，帧表见 MenuShotScript。
     member private this.RunMenuShot () =
         menuShotFrame <- menuShotFrame + 1L
@@ -1197,6 +1243,8 @@ type LivingVillageGame() as this =
                             storyShotStage)
                     printfn "story-shot=saved occupation=%s stage=%d" (Occupation.saveToken storyShotKind) storyShotStage
                     this.Exit()
+            if p36ShotMode && menu.Page = Playing && not relationView then
+                this.CaptureP36PromptShot()
 
     /// 启动画面：分层天色 + 屋脊/水面剪影 + 标题淡入上浮 + 跳过提示，全部为帧计数纯函数。
     member private this.DrawSplash() =