feat(desktop): LV_AUTOPLAY_SAMPLE 情境演示脚本

新增 SampleScript 状态机：进门→内景驻留→出门→走向 NPC
→打开对话→发送意图→关闭面板→走开，超时兜底进 SampleComplete。
Game.fs 读取 LV_AUTOPLAY_SAMPLE=1 切换 sample 模式（2x 模拟、
关闭旧 step 倍率、UpdateMenu 常开、独立 UpdatePlaying 分发）。
SampleTests 覆盖首步行走、进门、完整巡游（42/42 通过）。

1 files changed, 29 insertions, 5 deletions

diff --git a/src/LivingVillage.Desktop/Game.fs b/src/LivingVillage.Desktop/Game.fs
index 514928f..1245e02 100644
--- a/src/LivingVillage.Desktop/Game.fs
+++ b/src/LivingVillage.Desktop/Game.fs
@@ -96,9 +96,11 @@ type LivingVillageGame() as this =
 
     let autoplay = Environment.GetEnvironmentVariable("LV_AUTOPLAY") = "1"
     let autoplayFlow = Environment.GetEnvironmentVariable("LV_AUTOPLAY_FLOW") = "1"
+    let sampleMode = Environment.GetEnvironmentVariable("LV_AUTOPLAY_SAMPLE") = "1"
     let automated = autoplay || autoplayFlow
     let modeName =
-        if autoplayFlow then "autoplay-flow"
+        if sampleMode then "sample"
+        elif autoplayFlow then "autoplay-flow"
         elif autoplay then "autoplay"
         else "keyboard"
     let configuredStepsPerFrame =
@@ -110,6 +112,8 @@ type LivingVillageGame() as this =
             | _ -> 1
     let initialSimulationControl, initialLegacyStepsPerFrame =
         SimulationControl.initialForConfiguredSteps configuredStepsPerFrame
+    let startSimulationControl =
+        if sampleMode then SimulationControl.setSpeed TwoX initialSimulationControl else initialSimulationControl
     let savePath =
         match Environment.GetEnvironmentVariable("LV_SAVE_PATH") with
         | null | "" -> "living-village.save"
@@ -129,11 +133,12 @@ type LivingVillageGame() as this =
     let mutable relationView = false
     let mutable relationSnapshot: float32[,] option = None
     let mutable m5View = M5Interaction.initial
-    let mutable simulationControl = initialSimulationControl
-    let mutable legacyStepsPerFrame = initialLegacyStepsPerFrame
-    let mutable menu = MenuState.create initialSimulationControl false
+    let mutable simulationControl = startSimulationControl
+    let mutable legacyStepsPerFrame = (if sampleMode then None else initialLegacyStepsPerFrame)
+    let mutable menu = MenuState.create startSimulationControl false
     let mutable autoplayFrames = 0
     let mutable flowStep = 0
+    let mutable sampleState = SampleScript.initial
 
     do
         graphics.PreferredBackBufferWidth <- 1280
@@ -235,13 +240,32 @@ type LivingVillageGame() as this =
             else None
         match input with
         | Some nextInput -> this.DispatchMenuInput nextInput
-        | None when autoplay && not autoplayFlow && menu.Page = MainMenu && not menu.HasCurrentWorld ->
+        | None when (autoplay || sampleMode) && not autoplayFlow && menu.Page = MainMenu && not menu.HasCurrentWorld ->
             autoplayFrames <- autoplayFrames + 1
             if autoplayFrames >= 15 then
                 this.DispatchMenuInput Confirm
         | None -> ()
 
+    member private this.RunSampleMode () =
+        let stageBefore = sampleState.Stage
+        let positionBefore = world.Avatar.Pos
+        let nextWorld, nextView, nextState = SampleScript.runFrame world m5View sampleState
+        if nextWorld.Avatar.Pos <> positionBefore then
+            avatarFacing <- VillageArt.facingAfterMovement positionBefore nextWorld.Avatar.Pos avatarFacing
+        world <- nextWorld
+        m5View <- nextView
+        sampleState <- nextState
+        this.CenterCamera()
+        if nextState.Stage <> stageBefore then
+            printfn $"sample stage={nextState.Stage} tick={nextWorld.Tick} pos=({nextWorld.Avatar.Pos.X:F0},{nextWorld.Avatar.Pos.Y:F0})"
+
     member private this.UpdatePlaying (gameTime: GameTime) (kb: KeyboardState) (pressed: Keys -> bool) (pressedAny: Keys list -> bool) =
+        if sampleMode then
+            this.RunSampleMode()
+        else
+            this.UpdatePlayingManual gameTime kb pressed pressedAny
+
+    member private this.UpdatePlayingManual (gameTime: GameTime) (kb: KeyboardState) (pressed: Keys -> bool) (pressedAny: Keys list -> bool) =
         let mutable loadFailed = false
         let mutable leftGame = false
         let lPressed = pressed Keys.L