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, 161 insertions, 0 deletions

diff --git a/src/LivingVillage.Desktop/SampleScript.fs b/src/LivingVillage.Desktop/SampleScript.fs
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+namespace LivingVillage.Desktop
+
+open System
+open LivingVillage.Kernel
+open LivingVillage.Kernel.Sim
+open LivingVillage.Desktop.VillagePresentation
+
+module SampleScript =
+
+    type SampleStage =
+        | ApproachDoor
+        | InspectInterior
+        | LeaveDoorstep
+        | ApproachNpc
+        | ReadDialogueOptions
+        | CloseDialogue
+        | WalkAway
+        | SampleComplete
+
+    type SampleAction =
+        | NoAction
+        | MoveTo of Vec2
+        | PushM5 of M5Command
+
+    type SampleState =
+        { Stage: SampleStage
+          StageFrames: int
+          TotalFrames: int
+          DialogueTarget: NpcId option
+          TimedOut: bool }
+
+    let initial : SampleState =
+        { Stage = ApproachDoor
+          StageFrames = 0
+          TotalFrames = 0
+          DialogueTarget = None
+          TimedOut = false }
+
+    let private tileCenter (tile: TilePosition) : Vec2 =
+        { X = float32 (tile.X * Sim.tilePixels + Sim.tilePixels / 2)
+          Y = float32 (tile.Y * Sim.tilePixels + Sim.tilePixels / 2) }
+
+    let doorWorldCenter : Vec2 =
+        let home = (createScene ()).Homes |> List.head
+        tileCenter (worldTileForSceneTile home.Door)
+
+    let private leaveDoorstepCenter : Vec2 =
+        tileCenter (worldTileForSceneTile { X = 3; Y = 5 })
+
+    let private walkAwayCenter : Vec2 =
+        tileCenter (worldTileForSceneTile { X = 6; Y = 7 })
+
+    let private arriveRadius = 12.0f
+    let private inspectFrames = 150
+    let private dialogueHoldFrames = 120
+    let private totalFrameLimit = 20000
+
+    let private distanceSquared (a: Vec2) (b: Vec2) : float32 =
+        let dx = b.X - a.X
+        let dy = b.Y - a.Y
+        dx * dx + dy * dy
+
+    let private timeoutFor (stage: SampleStage) : int =
+        match stage with
+        | ApproachDoor -> 1800
+        | InspectInterior -> 600
+        | LeaveDoorstep -> 1800
+        | ApproachNpc -> 5400
+        | ReadDialogueOptions -> 120
+        | CloseDialogue -> 300
+        | WalkAway -> 3600
+        | SampleComplete -> Int32.MaxValue
+
+    let private advance (stage: SampleStage) (state: SampleState) : SampleState =
+        { state with Stage = stage; StageFrames = 0 }
+
+    let private nearestChatableNpc (world: World) : Npc option =
+        world.Npcs
+        |> Array.filter chatableForChat
+        |> Array.sortBy (fun npc -> distanceSquared world.Avatar.Pos npc.Pos, npc.Id)
+        |> Array.tryHead
+
+    let private timedOut (state: SampleState) : SampleState * SampleAction =
+        { state with Stage = SampleComplete; TimedOut = true }, NoAction
+
+    let step (world: World) (view: M5View) (state: SampleState) : SampleState * SampleAction =
+        let state =
+            { state with StageFrames = state.StageFrames + 1; TotalFrames = state.TotalFrames + 1 }
+        if state.TotalFrames > totalFrameLimit then
+            timedOut state
+        elif state.StageFrames >= timeoutFor state.Stage then
+            timedOut state
+        else
+            match state.Stage with
+            | SampleComplete -> state, NoAction
+            | ApproachDoor ->
+                match view.HomeMode with
+                | Inside _ -> advance InspectInterior state, NoAction
+                | Outside ->
+                    if distanceSquared world.Avatar.Pos doorWorldCenter <= arriveRadius * arriveRadius then
+                        state, PushM5 Interact
+                    else
+                        state, MoveTo doorWorldCenter
+            | InspectInterior ->
+                match view.HomeMode with
+                | Outside -> advance LeaveDoorstep state, NoAction
+                | Inside _ ->
+                    if state.StageFrames >= inspectFrames then
+                        state, PushM5 Interact
+                    else
+                        state, NoAction
+            | LeaveDoorstep ->
+                match view.HomeMode with
+                | Inside _ -> state, PushM5 Interact
+                | Outside ->
+                    if distanceSquared world.Avatar.Pos leaveDoorstepCenter <= arriveRadius * arriveRadius then
+                        advance ApproachNpc state, NoAction
+                    else
+                        state, MoveTo leaveDoorstepCenter
+            | ApproachNpc ->
+                match M5Interaction.resolveAction world Outside with
+                | Some { Action = TalkTo target } ->
+                    { advance ReadDialogueOptions state with DialogueTarget = Some target }, PushM5 Interact
+                | _ ->
+                    match nearestChatableNpc world with
+                    | Some npc -> state, MoveTo npc.Pos
+                    | None -> state, NoAction
+            | ReadDialogueOptions ->
+                if view.Panel = DialoguePanel && view.Menu.IsSome then
+                    state, PushM5 Intent1
+                else
+                    advance CloseDialogue state, NoAction
+            | CloseDialogue ->
+                if state.StageFrames >= dialogueHoldFrames then
+                    advance WalkAway state, PushM5 ClosePanel
+                else
+                    state, NoAction
+            | WalkAway ->
+                if distanceSquared world.Avatar.Pos walkAwayCenter <= arriveRadius * arriveRadius then
+                    advance SampleComplete state, NoAction
+                else
+                    state, MoveTo walkAwayCenter
+
+    let runFrame (world: World) (view: M5View) (state: SampleState) : World * M5View * SampleState =
+        let nextState, action = step world view state
+        let nextWorld, nextView =
+            match action with
+            | NoAction -> world, view
+            | PushM5 command -> M5Interaction.apply command world view
+            | MoveTo target ->
+                let dx = target.X - world.Avatar.Pos.X
+                let dy = target.Y - world.Avatar.Pos.Y
+                let length = sqrt (dx * dx + dy * dy)
+                let input =
+                    if length > 0.001f then
+                        { MoveX = dx / length; MoveY = dy / length }
+                    else
+                        { MoveX = 0.0f; MoveY = 0.0f }
+                let movedWorld = Sim.step { Input = input } world
+                movedWorld, view
+        nextWorld, M5Interaction.refreshPrompt nextWorld nextView, nextState