p74: 启动开场过渡（水墨式渐显）+ 开始界面布局回归

新增纯函数 InkReveal.fs（inkStrength ease-out 消散 + 6 滴预乘墨滴 dabs），DrawSplash 在场景层之上、标题之下绘制，与既有 reveal/veil 淡入叠加，形成可辨识水墨开场；单滴 alpha<255 且椭圆行落成，无实心黑块。开始界面沿用既有 开始/读档/退出（有档 继续）。新增 P74LaunchTransitionTests（4 例）与 LV_P74_SHOT/-analyze-p74 证据（5 帧墨幕非增、两两 diff>0，verdict=PASS）。HUD 结构未动；Desktop 350/350、Kernel 120/120、digest 与 p70 一致。

13 files changed, 318 insertions, 0 deletions

diff --git a/docs/evidence/p74-analysis.txt b/docs/evidence/p74-analysis.txt
new file mode 100644
index 0000000..907a063
--- /dev/null
+++ b/docs/evidence/p74-analysis.txt
@@ -0,0 +1,26 @@
+P74（启动开场过渡：水墨式渐显）证据分析 — 真实 Desktop xvfb 1280x720
+钩子：LV_P74_SHOT=1（60Hz 固定步进，splash 帧表 8/30/60/100/140 各一帧）
+路径：splashFrame → InkReveal.inkStrength/dabs（预乘墨滴）→ 露出天色/水面/屋脊/标题
+
+log shots: 8(ink=0.770), 30(ink=0.325), 60(ink=0.053), 100(ink=0.000), 140(ink=0.000)
+
+p74-splash-008.png: size=1280x720 brightness=46.5 std=25.6 dark_block=0 white_block=405
+p74-splash-030.png: size=1280x720 brightness=51.7 std=38.4 dark_block=0 white_block=232
+p74-splash-060.png: size=1280x720 brightness=56.0 std=48.9 dark_block=0 white_block=232
+p74-splash-100.png: size=1280x720 brightness=56.4 std=49.0 dark_block=0 white_block=232
+p74-splash-140.png: size=1280x720 brightness=56.4 std=49.1 dark_block=0 white_block=232
+
+diff frame 008 vs 030: differing_pixels=670116
+diff frame 008 vs 060: differing_pixels=686287
+diff frame 008 vs 100: differing_pixels=528158
+diff frame 008 vs 140: differing_pixels=537994
+diff frame 030 vs 060: differing_pixels=733221
+diff frame 030 vs 100: differing_pixels=692402
+diff frame 030 vs 140: differing_pixels=702640
+diff frame 060 vs 100: differing_pixels=525583
+diff frame 060 vs 140: differing_pixels=545037
+diff frame 100 vs 140: differing_pixels=120790
+
+verdict=PASS
+  ink strength decays to 0 across the captured frames; frames render 1280x720,
+  no big black/white blocks, and every pair differs (the opening transition animates).
diff --git a/docs/evidence/p74-splash-008.png b/docs/evidence/p74-splash-008.png
new file mode 100644
index 0000000..d0c1a01
--- /dev/null
+++ b/docs/evidence/p74-splash-008.png
diff --git a/docs/evidence/p74-splash-030.png b/docs/evidence/p74-splash-030.png
new file mode 100644
index 0000000..e42ba63
--- /dev/null
+++ b/docs/evidence/p74-splash-030.png
diff --git a/docs/evidence/p74-splash-060.png b/docs/evidence/p74-splash-060.png
new file mode 100644
index 0000000..401c0d4
--- /dev/null
+++ b/docs/evidence/p74-splash-060.png
diff --git a/docs/evidence/p74-splash-100.png b/docs/evidence/p74-splash-100.png
new file mode 100644
index 0000000..bce9efa
--- /dev/null
+++ b/docs/evidence/p74-splash-100.png
diff --git a/docs/evidence/p74-splash-140.png b/docs/evidence/p74-splash-140.png
new file mode 100644
index 0000000..71cef5a
--- /dev/null
+++ b/docs/evidence/p74-splash-140.png
diff --git a/docs/维护说明.md b/docs/维护说明.md
index 9d27dd1..3064e1a 100644
--- a/docs/维护说明.md
+++ b/docs/维护说明.md
@@ -209,6 +209,18 @@ 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`。
 
+## P74 启动开场过渡（水墨式渐显）
+
+- 新增纯函数模块 `InkReveal.fs`：`inkStrength`（起手 1，`dissolveFrames=96` 内 ease-out 退到 0）、
+  `dabs frame width height`（6 滴归一化种子墨滴，随消散半径外扩、alpha 下降）、`inkRgb=(26,36,52)`。
+  单滴 `alpha < 255` 且用 `VillageArt.ellipseRuns` + `premultiply` 落成柔光墨晕，**绝无实心黑块**。
+- 接线：`Game.DrawSplash` 在场景层（天色/云/屋脊/水面/灯笼）之上、标题之下绘制墨滴，与既有
+  `LaunchScreen.revealProgress/veilAlpha` 淡入/暗幕退场叠加，形成可辨识的水墨开场；HUD 结构未动。
+- **回归**：`P74LaunchTransitionTests`（墨幕单调消散且为 0、墨滴确定/随帧变化、alpha<255、
+  半径 < 半屏、`LaunchScreen` 不变量、开始界面三项 开始/读档/退出 + 有档 继续/读档/退出）。
+- **证据**：`LV_P74_SHOT=1`（60Hz 固定步进，splash 帧表 8/30/60/100/140 各一帧）→
+  `scripts/analyze-p74.py` 断言帧号/墨幕非增/无大黑块/两两 pixel diff>0，落 `docs/evidence/p74-*`。
+
 ## 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 /
diff --git a/scripts/analyze-p74.py b/scripts/analyze-p74.py
new file mode 100644
index 0000000..4569791
--- /dev/null
+++ b/scripts/analyze-p74.py
@@ -0,0 +1,132 @@
+#!/usr/bin/env python3
+"""P74（启动开场过渡：水墨式渐显）证据分析：真实 xvfb 录启动 0-3 秒序列抽帧。
+
+判据（读真实实跑日志 + 逐帧像素统计）：
+  1. 日志含 5 行 `p74-shot=p74-splash-<frame> inkStrength=<v>`，帧号递增 {8,30,60,100,140}。
+  2. inkStrength 随帧非增，且在 dissolveFrames(96) 后为 0（墨幕确实在消散）。
+  3. 抽帧 PNG：1280x720、非空白（std>=6）、无 24x24 纯黑块（标题/屋脊的纯白属预期，仅报告不判失败）。
+  4. 动画在变：任意两帧 pixel diff > 0（且首末帧 diff 显著）。
+  5. 画面「是否好看/水墨味」的 vision 复核由 Hermes 侧完成，非本脚本判据。
+
+Usage: python3 scripts/analyze-p74.py <record-dir> <out-txt>
+Exit 0 pass / 1 fail / 2 usage.
+"""
+
+import itertools
+import re
+import sys
+from pathlib import Path
+
+import numpy as np
+from PIL import Image
+
+SHOT_RE = re.compile(r"^p74-shot=p74-splash-(\d+) inkStrength=([\d.]+)$", re.MULTILINE)
+EXPECTED = [8, 30, 60, 100, 140]
+DARK_SIDE = 24
+DARK_MAX = 8
+WHITE_SIDE = 64
+WHITE_MIN = 250
+
+
+def max_block(rgba, side, predicate):
+    h, w = rgba.shape[0], rgba.shape[1]
+    if h < side or w < side:
+        return 0
+    mask = predicate(rgba).astype(np.int64)
+    integral = np.zeros((h + 1, w + 1), dtype=np.int64)
+    integral[1:, 1:] = mask.cumsum(axis=0).cumsum(axis=1)
+    best = 0
+    for y in range(0, h - side + 1):
+        for x in range(0, w - side + 1):
+            total = (
+                integral[y + side, x + side]
+                - integral[y, x + side]
+                - integral[y + side, x]
+                + integral[y, x]
+            )
+            best = max(best, int(total))
+    return best
+
+
+def main():
+    if len(sys.argv) != 3:
+        print(__doc__)
+        return 2
+    rec = Path(sys.argv[1])
+    out = Path(sys.argv[2])
+    log = (rec / "log.txt").read_text(encoding="utf-8", errors="replace")
+    failures = []
+    lines = [
+        "P74（启动开场过渡：水墨式渐显）证据分析 — 真实 Desktop xvfb 1280x720",
+        "钩子：LV_P74_SHOT=1（60Hz 固定步进，splash 帧表 8/30/60/100/140 各一帧）",
+        "路径：splashFrame → InkReveal.inkStrength/dabs（预乘墨滴）→ 露出天色/水面/屋脊/标题",
+        "",
+    ]
+
+    shots = [(int(m.group(1)), float(m.group(2))) for m in SHOT_RE.finditer(log)]
+    got = [f for f, _ in shots]
+    lines.append("log shots: " + ", ".join(f"{f}(ink={v:.3f})" for f, v in shots))
+    if got != EXPECTED:
+        failures.append(f"log frames {got} != expected {EXPECTED}")
+    strengths = [v for _, v in shots]
+    if strengths != sorted(strengths, reverse=True):
+        failures.append("inkStrength is not non-increasing across frames")
+    if not all(v == 0.0 for f, v in shots if f >= 96):
+        failures.append("inkStrength is not 0 after dissolveFrames (96)")
+    lines.append("")
+
+    stats = {}
+    for frame in EXPECTED:
+        path = rec / f"p74-splash-{frame:03d}.png"
+        if not path.exists():
+            failures.append(f"missing frame {path.name}")
+            continue
+        rgba = np.asarray(Image.open(path).convert("RGBA"), dtype=np.uint8)
+        rgb = rgba[:, :, :3].astype(np.float64)
+        h, w = rgb.shape[0], rgb.shape[1]
+        brightness = float(rgb.mean())
+        std = float(rgb.std())
+        dark = max_block(
+            rgba, DARK_SIDE,
+            lambda a: (a[:, :, 0] <= DARK_MAX) & (a[:, :, 1] <= DARK_MAX) & (a[:, :, 2] <= DARK_MAX) & (a[:, :, 3] >= 250),
+        )
+        white = max_block(
+            rgba, WHITE_SIDE,
+            lambda a: (a[:, :, 0] >= WHITE_MIN) & (a[:, :, 1] >= WHITE_MIN) & (a[:, :, 2] >= WHITE_MIN) & (a[:, :, 3] >= 250),
+        )
+        stats[frame] = {"brightness": brightness, "std": std}
+        lines.append(f"p74-splash-{frame:03d}.png: size={w}x{h} brightness={brightness:.1f} std={std:.1f} dark_block={dark} white_block={white}")
+        if (w, h) != (1280, 720):
+            failures.append(f"{path.name} size {w}x{h} != 1280x720")
+        if std < 6.0:
+            failures.append(f"{path.name} looks blank (std={std:.1f})")
+        if dark > 0:
+            failures.append(f"{path.name} has {DARK_SIDE}x{DARK_SIDE} pure-black block")
+    lines.append("")
+
+    have = [f for f in EXPECTED if f in stats]
+    for a, b in itertools.combinations(have, 2):
+        ia = np.asarray(Image.open(rec / f"p74-splash-{a:03d}.png").convert("RGB"), dtype=np.int16)
+        ib = np.asarray(Image.open(rec / f"p74-splash-{b:03d}.png").convert("RGB"), dtype=np.int16)
+        differing = int((np.abs(ia - ib).sum(axis=2) > 0).sum())
+        lines.append(f"diff frame {a:03d} vs {b:03d}: differing_pixels={differing}")
+        if differing == 0:
+            failures.append(f"frame {a} identical to {b}")
+
+    lines.append("")
+    if failures:
+        lines.append("verdict=FAIL")
+        for f in failures:
+            lines.append("  - " + f)
+    else:
+        lines.append("verdict=PASS")
+        lines.append("  ink strength decays to 0 across the captured frames; frames render 1280x720,")
+        lines.append("  no big black blocks, and every pair differs (the opening transition animates).")
+    out.parent.mkdir(parents=True, exist_ok=True)
+    out.write_text("\n".join(lines) + "\n", encoding="utf-8")
+    print(f"wrote {out} verdict={'FAIL' if failures else 'PASS'}")
+    return 1 if failures else 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())
diff --git a/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj b/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj
index 11a1b90..fb7ecb7 100644
--- a/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj
+++ b/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj
@@ -45,6 +45,7 @@
     <Compile Include="P71ApiDocsTests.fs" />
     <Compile Include="P72CharacterWalkTests.fs" />
     <Compile Include="P73LightingTierTests.fs" />
+    <Compile Include="P74LaunchTransitionTests.fs" />
     <Compile Include="SampleTests.fs" />
   </ItemGroup>
 
diff --git a/src/LivingVillage.Desktop.Tests/P74LaunchTransitionTests.fs b/src/LivingVillage.Desktop.Tests/P74LaunchTransitionTests.fs
new file mode 100644
index 0000000..880f33b
--- /dev/null
+++ b/src/LivingVillage.Desktop.Tests/P74LaunchTransitionTests.fs
@@ -0,0 +1,59 @@
+namespace LivingVillage.Desktop.Tests
+
+open Microsoft.VisualStudio.TestTools.UnitTesting
+open LivingVillage.Desktop
+open LivingVillage.Kernel
+open LivingVillage.Kernel.Sim
+
+/// P74 回归：启动开场过渡（水墨渐显）纯函数性质 + 开始界面布局入口。
+[<TestClass>]
+type P74LaunchTransitionTests () =
+
+    let width = 1280
+    let height = 720
+
+    [<TestMethod>]
+    member _.InkRevealDissolvesMonotonicallyAndStaysSoft () =
+        // 起手满墨、96 帧后散尽，且整体强度随帧非增（确定性 ease-out）。
+        Assert.AreEqual<float32>(1.0f, InkReveal.inkStrength 0L)
+        Assert.AreEqual<float32>(0.0f, InkReveal.inkStrength InkReveal.dissolveFrames)
+        Assert.AreEqual<float32>(0.0f, InkReveal.inkStrength 140L)
+        let strengths = [ 0L; 8L; 30L; 60L; 95L ] |> List.map InkReveal.inkStrength
+        Assert.AreEqual<float32 list>(strengths, strengths |> List.sortDescending)
+        // 墨滴始终存在、均在画布内、alpha < 255（柔和墨晕，非实心黑块）、半径不覆盖半屏。
+        for frame in [ 0L; 8L; 30L; 60L; 95L ] do
+            let dabs = InkReveal.dabs frame width height
+            Assert.IsTrue(dabs.Length > 0, "墨滴集合不得为空")
+            for dab in dabs do
+                Assert.IsTrue(dab.Alpha >= 0 && dab.Alpha < 255, sprintf "alpha %d 越界" dab.Alpha)
+                Assert.IsTrue(dab.Rx > 0 && dab.Rx < width / 2, "Rx 覆盖过半屏")
+                Assert.IsTrue(dab.Ry > 0 && dab.Ry < height / 2, "Ry 覆盖过半屏")
+
+    [<TestMethod>]
+    member _.InkRevealDabsChangeOverTheTransition () =
+        // 同一帧两次调用一致（确定性）；不同帧墨滴布局不同（动画在变）。
+        Assert.AreEqual<InkReveal.Dab list>(InkReveal.dabs 20L width height, InkReveal.dabs 20L width height)
+        Assert.AreNotEqual<InkReveal.Dab list>(InkReveal.dabs 8L width height, InkReveal.dabs 60L width height)
+
+    [<TestMethod>]
+    member _.LaunchScreenTransitionIsDeterministic () =
+        Assert.AreEqual<float32>(0.0f, LaunchScreen.revealProgress 0L)
+        Assert.AreEqual<float32>(1.0f, LaunchScreen.revealProgress LaunchScreen.fadeInFrames)
+        Assert.AreEqual<float32>(1.0f, LaunchScreen.veilAlpha 0L)
+        Assert.AreEqual<float32>(0.0f, LaunchScreen.veilAlpha LaunchScreen.durationFrames)
+        Assert.IsTrue(LaunchScreen.isComplete LaunchScreen.durationFrames)
+        Assert.IsFalse(LaunchScreen.isComplete (LaunchScreen.durationFrames - 1L))
+        Assert.AreEqual<string>("江南水乡", LaunchScreen.title)
+
+    [<TestMethod>]
+    member _.StartMenuLayoutExposesStartLoadExit () =
+        // 开场结束后的可交互开始界面：无存档 → 开始/读档/退出。
+        let fresh = MenuState.create { Paused = false; Speed = OneX } false
+        Assert.AreEqual<MenuPage>(MainMenu, fresh.Page)
+        Assert.AreEqual<MenuItem list>([ NewGameItem; LoadItem; ExitItem ], MenuState.items fresh)
+        let labels = MenuState.items fresh |> List.map MenuState.itemLabel
+        Assert.AreEqual<string list>([ "开始"; "读档"; "退出" ], labels)
+        // 有进行中的世界 → 继续/读档/退出。
+        let resumed = MenuState.create { Paused = false; Speed = OneX } true
+        Assert.AreEqual<MenuItem list>([ ContinueItem; LoadItem; ExitItem ], MenuState.items resumed)
+        Assert.AreEqual<string>("继续", MenuState.itemLabel (MenuState.selectedItem resumed))
diff --git a/src/LivingVillage.Desktop/Game.fs b/src/LivingVillage.Desktop/Game.fs
index 3d04ca7..a4f994b 100644
--- a/src/LivingVillage.Desktop/Game.fs
+++ b/src/LivingVillage.Desktop/Game.fs
@@ -319,6 +319,10 @@ type LivingVillageGame() as this =
     let p42ShotMode = Environment.GetEnvironmentVariable("LV_P42_SHOT") = "1"
     let mutable p42SplashEarlyDone = false
     let mutable p42SplashLateDone = false
+    // P74 证据钩子：LV_P74_SHOT=1 时在 60Hz 固定步进下按 splash 帧表拍开场过渡序列，拍完退出。
+    let p74ShotMode = Environment.GetEnvironmentVariable("LV_P74_SHOT") = "1"
+    let p74Frames = [ 8L; 30L; 60L; 100L; 140L ]
+    let mutable p74Saved = Set.empty<int64>
     // P43 证据钩子：LV_P43_SHOT=1 时在真实世界里拍昼/夜两张 HUD 整帧（日历钟卡 + 体力条 + 10 格 hotbar）。
     let p43ShotMode = Environment.GetEnvironmentVariable("LV_P43_SHOT") = "1"
     let mutable p43Step = 0
@@ -2617,6 +2621,20 @@ type LivingVillageGame() as this =
             printfn "p42-shot=done"
             this.Exit()
 
+    /// P74 证据：splash 帧表逐帧落盘（证明开场过渡在变），拍完即退出。
+    member private this.CaptureP74Shot () =
+        if splashActive then
+            match p74Frames |> List.tryFind (fun f -> not (Set.contains f p74Saved) && splashFrame >= f) with
+            | Some frame ->
+                p74Saved <- Set.add frame p74Saved
+                System.IO.Directory.CreateDirectory recordDirectory |> ignore
+                this.SaveBackBuffer(sprintf "%s/p74-splash-%03d.png" recordDirectory frame)
+                printfn "p74-shot=p74-splash-%03d inkStrength=%.3f" frame (InkReveal.inkStrength splashFrame)
+            | None -> ()
+            if p74Saved.Count >= p74Frames.Length then
+                printfn "p74-shot=done"
+                this.Exit()
+
     /// P20 证据：把一次 MapGen 绘制渲染到指定尺寸离屏 target，返回绘制瓦片数与纹理。
     /// P28：可传入世界 tint 与可选 veil tick（夜景取证用）。
     member private this.RenderMapGen (targetWidth: int) (targetHeight: int) (camX: int) (camY: int) (drawFitted: bool) (tint: Color) (veilTick: int64 option) : int * Texture2D =
@@ -2867,6 +2885,8 @@ type LivingVillageGame() as this =
                 this.CaptureMenuShot()
             if p42ShotMode then
                 this.CaptureP42Shot()
+            if p74ShotMode then
+                this.CaptureP74Shot()
             if storyShotMode && storyShotPrepared then
                 storyShotFrame <- storyShotFrame + 1L
                 if not storyShotSaved && storyShotFrame = 20L then
@@ -2990,6 +3010,15 @@ type LivingVillageGame() as this =
             spriteBatch.Draw(pixel, Rectangle(lx - 1, ly - 7, 4, 2), Color(90, 60, 40))
             spriteBatch.Draw(pixel, Rectangle(lx - 2, ly + 5, 6, 2), Color(90, 60, 40))
 
+        // P74 水墨式渐显：柔和墨滴从画布各处晕开、随帧消散，露出后方天色/水面/屋脊。
+        // 单滴 alpha < 255 且用预乘椭圆行落成，绝无实心黑块；绘在标题之下、场景之上。
+        let inkR, inkG, inkB = InkReveal.inkRgb
+        for dab in InkReveal.dabs splashFrame width height do
+            if dab.Alpha > 0 then
+                let inkColor = VillageArt.premultiply inkR inkG inkB dab.Alpha
+                for (runX, runY, runW) in VillageArt.ellipseRuns dab.X dab.Y dab.Rx dab.Ry do
+                    spriteBatch.Draw(pixel, Rectangle(runX, runY, runW, 1), inkColor)
+
         // 标题：淡入 + 上浮，先画深色投影再画亮面。
         let titleRise = int (24.0f * (1.0f - reveal))
         PixelText.draw spriteBatch pixel cjkAtlas (layout.TitleX + 4) (layout.TitleY + titleRise + 4) layout.TitleScale (Color(12, 20, 28, alpha 255)) LaunchScreen.title
diff --git a/src/LivingVillage.Desktop/InkReveal.fs b/src/LivingVillage.Desktop/InkReveal.fs
new file mode 100644
index 0000000..04c1675
--- /dev/null
+++ b/src/LivingVillage.Desktop/InkReveal.fs
@@ -0,0 +1,58 @@
+namespace LivingVillage.Desktop
+
+open System
+
+/// P74 启动开场过渡：纯程序实现的水墨式渐显。
+/// 启动最初数帧用若干柔和墨滴（预乘 alpha 椭圆行，绝无整屏纯色/大黑块）从中心向外
+/// 晕开，同时整体墨幕强度随帧 ease-out 消退，露出后方的天色/水面/屋脊/标题。
+/// 全部为帧计数与画布尺寸的纯函数，确定性可复现；Kernel 不参与。
+module InkReveal =
+
+    /// 墨幕完全消散所需帧数（< LaunchScreen.durationFrames，先散墨再见标题）。
+    let dissolveFrames = 96L
+
+    /// 单滴墨的最大 alpha：始终 < 255，保证是柔光墨晕而非实心黑块。
+    let maxAlpha = 200
+
+    /// 墨滴种子：归一化中心 + 归一化基准半径 + 相位（纯数据，确定性布局）。
+    let private seeds : (float32 * float32 * float32 * float32 * int) list =
+        [ (0.22f, 0.30f, 0.14f, 0.10f, 0)
+          (0.46f, 0.22f, 0.18f, 0.12f, 1)
+          (0.74f, 0.34f, 0.12f, 0.10f, 2)
+          (0.58f, 0.62f, 0.20f, 0.13f, 3)
+          (0.30f, 0.70f, 0.16f, 0.11f, 4)
+          (0.83f, 0.67f, 0.11f, 0.08f, 5) ]
+
+    let private clamp01 (v: float32) = if v < 0.0f then 0.0f elif v > 1.0f then 1.0f else v
+
+    /// 整体墨幕强度：起手 1，随帧 ease-out 退到 0（dissolveFrames 后为 0）。
+    let inkStrength (frame: int64) : float32 =
+        if frame <= 0L then 1.0f
+        elif frame >= dissolveFrames then 0.0f
+        else
+            let t = clamp01 (float32 frame / float32 dissolveFrames)
+            1.0f - t |> fun remaining -> remaining * remaining * remaining
+
+    /// 一滴墨：像素中心/半径/alpha。alpha 已含墨幕强度，绘制方按 alpha 预乘 rgb。
+    type Dab =
+        { X: int
+          Y: int
+          Rx: int
+          Ry: int
+          Alpha: int }
+
+    /// 当前帧的墨滴集合：消散过程中半径外扩、alpha 下降，读起来像墨在水中晕开。
+    let dabs (frame: int64) (width: int) (height: int) : Dab list =
+        let strength = inkStrength frame
+        let expand = 1.0f + 0.9f * (1.0f - strength)
+        seeds
+        |> List.map (fun (cx, cy, brx, bry, phase) ->
+            let wobble = 1.0f + 0.06f * float32 (sin (float (phase) * 1.7))
+            { X = int (cx * float32 width)
+              Y = int (cy * float32 height)
+              Rx = max 1 (int (brx * float32 width * expand * wobble))
+              Ry = max 1 (int (bry * float32 height * expand * wobble))
+              Alpha = int (float32 maxAlpha * strength) })
+
+    /// 墨色（深靛而非纯黑），绘制时与 alpha 预乘。
+    let inkRgb : int * int * int = (26, 36, 52)
diff --git a/src/LivingVillage.Desktop/LivingVillage.Desktop.fsproj b/src/LivingVillage.Desktop/LivingVillage.Desktop.fsproj
index 7243705..8abbdd6 100644
--- a/src/LivingVillage.Desktop/LivingVillage.Desktop.fsproj
+++ b/src/LivingVillage.Desktop/LivingVillage.Desktop.fsproj
@@ -21,6 +21,7 @@
     <Compile Include="ChineseText.fs" />
     <Compile Include="CjkGlyphAtlas.fs" />
     <Compile Include="LaunchScreen.fs" />
+    <Compile Include="InkReveal.fs" />
     <Compile Include="MenuState.fs" />
     <Compile Include="Interaction.fs" />
     <Compile Include="SampleScript.fs" />