test(desktop): P17 取证钩子（LV_AUTOPLAY_START_HOUR 纯函数起时）+ 证据与 docs 记录

4 files changed, 55 insertions, 1 deletions

diff --git a/docs/维护说明.md b/docs/维护说明.md
index ad68e5b..024248f 100644
--- a/docs/维护说明.md
+++ b/docs/维护说明.md
@@ -173,6 +173,28 @@ dotnet src/LivingVillage.Headless/bin/Release/net8.0/LivingVillage.Headless.dll
 - 门槛：clean rebuild 0 警告 0 错误；`final_digest=953775FAEB2FDDE97289491AA260BD8D390C571E48A7A13AD2CB6FB7124F7F6C`
   一致、`performance_determinism=PASS`。
 
+## P17 批验：场景细节 / 人物动效 / 昼夜光照精修
+
+- ①街边中式细节物：`scripts/make-jiangnan-art.py` 世界图集由 25 格扩到 28 格（新增 slot 25 石灯笼 /
+  26 水缸 / 27 摊贩摊位，全部烘焙进 `Assets/jiangnan-world.png`，尺寸 800x32→896x32），游戏侧只做
+  `tileSourceRectangle` 贴片、无程序几何。`VillageArt` 新增 `RenderPropKind.StoneLantern/WaterVat/
+  MarketStall` 与 `worldTileCount=28`；`sampleRenderPlan` 沿石路摆 4 件（石灯笼 4,14 / 16,14，水缸
+  12,11，摊位 3,11）。图集脚本二次运行 byte-identical（sha256 一致）。
+- ②村民走路节奏差异化：`VillageArt` 新增 `NpcTrade`（Farmer/Peddler/Scholar，按 `NpcId mod 3` 纯函数
+  分配）与 `WalkRhythm`（走路/待机窗口 + 相位）。农夫 4/24、货郎 3/20（更快）、书生 6/36（更慢）；
+  `npcSpriteSpec` 改走各自节奏，`animationFrame/idleFrame/characterFrame` 保持农夫节奏即旧语义。
+- ③昼夜光照精修：`M6Presentation.lightingBlend` 过渡窗口参数化（清晨 4:00→6:30、黄昏 19:30→22:00）
+  并把小时改分数（原为整数小时，过渡只有 3 档），新增纯函数 `transitionWarmth`（晨昏中点火暖色峰值
+  1，正午/午夜 0）驱动 `backgroundAtWarmth/worldTintAtWarmth`，`M6RenderProfile` 增 `SkyWarmth`。
+- ④回归：更新/新增确定性测试（行走节奏、光照锚点与暖色、图集 28 格与 PNG 尺寸、证据起时纯函数）；
+  Desktop 107 / Kernel 89 全绿（未触碰 Kernel/Sim.fs 数值路径）。
+- ⑤证据：`/tmp/opencode/lv-p17-art/`（`p17-day-0{1,2}.png`、`p17-dusk-0{1,2}.png`、`p17-night-0{1,2}.png`、
+  `p17-diff-before-dawn.png` vs `p17-diff-after-dawn.png`（同一 6:00 tick，P17 前/后各 1 帧）、`sample.mp4`
+  13.1 s）；`check-no-white-blocks.py` 对所选 6 帧 0 命中。起时用新增环境钩子 `LV_AUTOPLAY_START_HOUR`
+  （纯函数 `M6Presentation.startTickForHour`，桌面演示专用，不进 Kernel）。
+- 门槛：clean rebuild 0 警告 0 错误；`final_digest=953775FAEB2FDDE97289491AA260BD8D390C571E48A7A13AD2CB6FB7124F7F6C`
+  一致、`performance_determinism=PASS`。
+
 ## 已验证命令
 
 ```bash
@@ -205,6 +227,15 @@ timeout 90 xvfb-run -a -s "-screen 0 1280x720x24" env \
   LV_AUTOPLAY_MENU_SHOT=1 LV_RECORD_DIR=/tmp/opencode/lv-p16-art \
   dotnet src/LivingVillage.Desktop/bin/Release/net8.0/LivingVillage.Desktop.dll
 
+# P17 取证（街边细节/人物节奏/昼夜精修；LV_AUTOPLAY_START_HOUR 定起时：昼 12 / 黄昏 20.75 / 夜 0）
+for spec in "day 12.0" "dusk 20.75" "night 0.0"; do set -- $spec; \
+  timeout 100 xvfb-run -a -s "-screen 0 1280x720x24" env LV_AUTOPLAY_SAMPLE=1 \
+    LV_AUTOPLAY_START_HOUR=$2 LV_AUTOPLAY_RECORD=1 \
+    LV_RECORD_DIR=/tmp/opencode/lv-p17-art/$1 LV_RECORD_EVERY=2 \
+    dotnet src/LivingVillage.Desktop/bin/Release/net8.0/LivingVillage.Desktop.dll; done
+# 街边细节图集再生成（确定性，二次运行 byte-identical）
+python3 scripts/make-jiangnan-art.py
+
 # P13 动画证据（确定性接触表 + 真实运行帧）
 python3 scripts/make-animation-evidence.py        # -> evidence/walk-idle-frames.png 等
 # 真实运行帧（白天 / 夜晚各一次；record 目录与间隔可用环境变量覆盖）
@@ -235,6 +266,8 @@ python3 scripts/check-no-white-blocks.py evidence/night-run
 - `/tmp/opencode/lv-p13/evidence/`（P13：`walk-idle-frames.png`、`water-3phase.png`、
   `smoke-3phase.png`、`water-2frame.png`、`smoke-2frame.png`、`day-panorama.png`、
   `night-lantern.png`、`day-night-compare.png`、`walk-real-run.png`、`day-run/`、`night-run/`）
+- `/tmp/opencode/lv-p17-art/`（P17：`p17-day-0{1,2}.png`、`p17-dusk-0{1,2}.png`、`p17-night-0{1,2}.png`、
+  `p17-diff-before-dawn.png`/`p17-diff-after-dawn.png`、`sample.mp4`；同一份拷入 `evidence/`）
 - `/tmp/opencode/lv-p16-art/`（P16：`frame-day-0{1,2,3}.png`、`frame-night-0{1,2,3}.png`、
   `frame-splash-01.png`、`frame-menu-0{1,2}.png`、`hud-bar-day.png`、`hud-bar-night.png`、
   `sample.mp4`、`final_verification.txt`；沙箱不允许 `/tmp/lv-p16-art`，故落此路径）
diff --git a/src/LivingVillage.Desktop.Tests/PrototypeTests.fs b/src/LivingVillage.Desktop.Tests/PrototypeTests.fs
index 5a153b1..4d2c895 100644
--- a/src/LivingVillage.Desktop.Tests/PrototypeTests.fs
+++ b/src/LivingVillage.Desktop.Tests/PrototypeTests.fs
@@ -897,6 +897,10 @@ type PrototypeTests () =
         Assert.AreEqual<float32>(0.0f, (atHour 13).LanternGlow)
         Assert.AreEqual<float32>(1.0f, (atHour 0).LanternGlow)
 
+        // Evidence hook: fractional start hours map exactly onto sim ticks.
+        Assert.AreEqual<int64>(int64 20 * ticksPerHour + ticksPerHour * 3L / 4L, M6Presentation.startTickForHour 20.75)
+        Assert.AreEqual<int64>(6L * ticksPerHour, M6Presentation.startTickForHour 6.0)
+
     [<TestMethod>]
     member _.TitleEntranceProgressIsDeterministicAndCompleteAfterTwoSeconds () =
         // 120 frames at the fixed 60Hz step = 2s entrance, pure function of frame count.
diff --git a/src/LivingVillage.Desktop/Game.fs b/src/LivingVillage.Desktop/Game.fs
index 3f3a1d8..4760d4e 100644
--- a/src/LivingVillage.Desktop/Game.fs
+++ b/src/LivingVillage.Desktop/Game.fs
@@ -126,8 +126,21 @@ type LivingVillageGame() as this =
     let mutable cjkAtlas = Unchecked.defaultof<Texture2D>
     let mutable pixel = Unchecked.defaultof<Texture2D>
     let renderPlan = VillageArt.sampleRenderPlan ()
+    // Evidence hook: pin the starting wall-clock hour (e.g. 20.75 for 黄昏), desktop-only.
+    let startHourOverride =
+        match Environment.GetEnvironmentVariable("LV_AUTOPLAY_START_HOUR") with
+        | null | "" -> None
+        | value ->
+            match Double.TryParse(value, Globalization.NumberStyles.Float, Globalization.CultureInfo.InvariantCulture) with
+            | true, hour -> Some hour
+            | _ -> None
     let createInitialWorld () =
-        WorldBootstrap.initialWorldForDaylight daylightAutoplay 42UL Sim.npcCount
+        let baseWorld = WorldBootstrap.initialWorldForDaylight daylightAutoplay 42UL Sim.npcCount
+        match startHourOverride with
+        | Some hour ->
+            let tick = M6Presentation.startTickForHour hour
+            { baseWorld with Tick = tick; Time = float tick * Sim.dtSeconds }
+        | None -> baseWorld
     let mutable world = createInitialWorld ()
     let mutable camera = Vector2.Zero
     let mutable avatarFacing = VillageArt.SouthFacing
diff --git a/src/LivingVillage.Desktop/M6Presentation.fs b/src/LivingVillage.Desktop/M6Presentation.fs
index 11399c0..a64d494 100644
--- a/src/LivingVillage.Desktop/M6Presentation.fs
+++ b/src/LivingVillage.Desktop/M6Presentation.fs
@@ -100,6 +100,10 @@ module M6Presentation =
     /// 倍速标签（语义别名，HUD 用）。
     let speedLabel (control: SimulationControl) : string = clockLabel control
 
+    /// Deterministic start tick for a wall-clock hour (evidence harness): 20.75 -> 20:45.
+    let startTickForHour (hour: float) : int64 =
+        int64 (hour * float (Sim.ticksPerDay / 24L))
+
     let private hourOf (tick: int64) : int =
         int ((tick / (Sim.ticksPerDay / 24L)) % 24L)