feat(art): P33 接入 CC0 真实像素素材样板（地面+角色竖直切片）

- 修复 make-cc0-art.py 地块取样间距：packed sheet 无间距(16px pitch)，旧 17px 误采错格
- 重选草地/石板格 (9,8)/(10,8)/(4,8)/(4,9)，整数 2x NEAREST 重建 cc0-tiles.png
- VillageArt 暴露 selectedGround/CharacterAtlasRelativePath 纯函数，保留 LV_ASSET_PACK=cc0
  开关与程序绘制江南图集 fallback
- 新增 AssetPackTests：图集加载尺寸、整数倍缩放、开关/回退断言
- docs/素材来源.md 记录来源/许可/sha256/构建/开关；同步 assets-and-licenses 与维护说明 P33 小节
- docs/evidence/p33-atlas-*.png 昼/夜/2x 特写/程序绘制对照（check-no-white-blocks 0 命中）

12 files changed, 209 insertions, 11 deletions

diff --git a/docs/assets-and-licenses.md b/docs/assets-and-licenses.md
index 10bd69e..1d691a7 100644
--- a/docs/assets-and-licenses.md
+++ b/docs/assets-and-licenses.md
@@ -8,7 +8,11 @@
   - 来源：`/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc`，字体族包含 Noto Sans CJK SC。
   - 许可：SIL Open Font License 1.1；本地版权文件 SHA-256：`849f4ea9c214fa4ac3593b770c699f387534b11ce671264c1b10d85bdcb5997b`。
   - 参考：<https://raw.githubusercontent.com/notofonts/noto-cjk/main/README.md>。
-- **其他外部美术资产**：当前仓库没有 JPG、GIF、SVG、其他字体或音频文件。设计文档提到的 Kenney CC 资产只是候选方向，未随仓库或 M6c 包分发。
+- **第三方 CC0 真实像素素材图集（P33 起）**：`src/LivingVillage.Desktop/Assets/cc0-tiles.png`（128x32，地块）与 `cc0-characters.png`（3840x48，角色）由 `scripts/make-cc0-art.py` 从两个 CC0 素材包确定性再生成（整数 2x NEAREST）：
+  - **Kenney Tiny Farm 1.0**：来源 <https://kenney.nl/assets/tiny-farm>，许可 CC0 1.0（包内 `License.txt`），zip SHA-256 `a06f75f3…decc`。
+  - **Puny Characters（Shade）**：来源 <https://opengameart.org/content/puny-characters>，许可 CC0 1.0（发布页），zip SHA-256 `971d7b07…320e`。
+  - 原始 zip 记录于 `third_party/`；用途/构建/开关详见 `docs/素材来源.md`。运行时仅在 `LV_ASSET_PACK=cc0` 时启用，默认仍走程序绘制江南图集。
+- **其他外部美术资产**：当前仓库没有 JPG、GIF、SVG、其他字体或音频文件。
 - **Task 3b 边界**：中文 UI 使用上述许可明确的派生字形图集；场景、角色和其他 UI 图形仍由仓库代码生成，不下载或声称拥有未包含的第三方素材。
 
 ## 第三方运行依赖
diff --git a/docs/evidence/p33-atlas-baseline-day.png b/docs/evidence/p33-atlas-baseline-day.png
new file mode 100644
index 0000000..d8364e6
--- /dev/null
+++ b/docs/evidence/p33-atlas-baseline-day.png
diff --git a/docs/evidence/p33-atlas-closeup-2x.png b/docs/evidence/p33-atlas-closeup-2x.png
new file mode 100644
index 0000000..37e34ce
--- /dev/null
+++ b/docs/evidence/p33-atlas-closeup-2x.png
diff --git a/docs/evidence/p33-atlas-day.png b/docs/evidence/p33-atlas-day.png
new file mode 100644
index 0000000..ed6419f
--- /dev/null
+++ b/docs/evidence/p33-atlas-day.png
diff --git a/docs/evidence/p33-atlas-night.png b/docs/evidence/p33-atlas-night.png
new file mode 100644
index 0000000..68fa823
--- /dev/null
+++ b/docs/evidence/p33-atlas-night.png
diff --git a/docs/素材来源.md b/docs/素材来源.md
new file mode 100644
index 0000000..dd193de
--- /dev/null
+++ b/docs/素材来源.md
@@ -0,0 +1,53 @@
+# 第三方像素素材来源与许可
+
+P33 开始把「程序几何绘制」的样例村庄逐步替换为**真实像素素材**（统一像素风格）。
+本单只做第一条竖直切片：样例村庄的一类地面（草地/石板）与一类角色（村民/主角）接入
+CC0 素材，其余仍走原程序绘制江南图集作为 fallback。
+
+- **开关**：`LV_ASSET_PACK=cc0` 时启用真实素材包；未设置或取其它值一律回退到程序绘制
+  图集（`Assets/jiangnan-*.png`）。图集选择入口见 `src/LivingVillage.Desktop/VillageArt.fs`
+  的 `useCc0Pack` / `selectedGroundAtlasRelativePath` / `selectedCharacterAtlasRelativePath`。
+- **构建命令**（确定性，二次运行 byte-identical）：
+
+  ```bash
+  python3 scripts/make-cc0-art.py
+  # -> src/LivingVillage.Desktop/Assets/cc0-tiles.png       128x32  (4 个 32x32 地面格)
+  # -> src/LivingVillage.Desktop/Assets/cc0-characters.png 3840x48 (5 变体 x 4 向 x 6 帧, 32x48 格)
+  ```
+
+  源素材 16x16 / 16x24，**整数 2x NEAREST** 放大到 32x32 / 32x48；缩放断言见
+  `src/LivingVillage.Desktop.Tests/AssetPackTests.fs`。
+
+## 1. Kenney Tiny Farm（地块）
+
+- 名称/版本：Tiny Farm（1.0），作者 Kenney。
+- 来源页：<https://kenney.nl/assets/tiny-farm>
+- 直链：<https://kenney.nl/media/pages/assets/tiny-farm/dfded1ae3e-1782913588/kenney_tiny-farm.zip>
+- 许可：**CC0 1.0**（包内 `License.txt` 已保留于 `third_party/kenney_tiny-farm/License.txt`）。
+- 本地原始包：`third_party/kenney_tiny-farm.zip`
+- SHA-256：`a06f75f312c27eff15a2288475612e6f6699411be7259d408323cd15a790decc`（191128 bytes）
+- 获取日期：2026-09-21
+- 用法：取 `Tilemap/tilemap_packed.png`（192x176，12x11 格，**无间距、16px pitch**；带间距的
+  `tilemap.png` 为 203x186/17px）。本单取 (9,8)/(10,8) 两档草 + (4,8)/(4,9) 石板，
+  整数 2x 生成 `Assets/cc0-tiles.png`。
+
+## 2. Puny Characters（角色）
+
+- 名称：Puny Characters，作者 Shade。
+- 来源页：<https://opengameart.org/content/puny-characters>（附件直链 `puny-characters.zip`）
+- 许可：**CC0 1.0**（OpenGameArt 页面 License(s): CC0，itch.io 发布页同为 CC0；包内无独立
+  许可文件，以发布页为准）。
+- 本地原始包：`third_party/puny-characters.zip`
+- SHA-256：`971d7b07eea18fb2cce475cd6554a176ebf783bb064dec5a637ba33c7829320e`（235985 bytes）
+- 获取日期：2026-09-21
+- 用法：每个角色图 768x256（8 行 x 24 列，约 32px pitch）；取南向 16x24 取带，整数 2x 放到
+  32x48 格。包只提供南向姿态，北向复用南向、东/西为镜像（限制沿用 `scripts/make-cc0-art.py`
+  注释）。生成 `Assets/cc0-characters.png`。
+
+## 说明
+
+- 两者原始 zip 均随仓库记录于 `third_party/`（`PROVENANCE.md` 为总来源记录），仓库分发的
+  只是上述再生成图集，不声称拥有未包含素材。
+- 版权/许可复核：见 `third_party/` 内原始文件与发布页；重跑 `make-cc0-art.py` 前后对
+  `third_party/*.zip` 重新 `sha256sum` 校验（本单校验一致）。
+- 「中式元素补绘」为后续切片；本单只接入基础地块与一类角色，保证管线跑通。
diff --git a/docs/维护说明.md b/docs/维护说明.md
index c8047c8..96dcecd 100644
--- a/docs/维护说明.md
+++ b/docs/维护说明.md
@@ -1033,3 +1033,43 @@ python3 scripts/check-no-white-blocks.py /tmp/opencode/lv-p32-evidence/night
 说明：`DrawMapFitted` 生成器渲染路径不绘制炊烟（炊烟只在样例村庄 `VillageArt.drawWorld` 的
 late pass），故「灯笼光晕 + 水面」以生成器夜帧为准，「炊烟」见样例村庄昼间特写。所有帧
 `check-no-white-blocks.py` 0 命中（无 ≥64x64 不透明纯白块）。
+
+## P33 素材接入样板（真实像素素材竖直切片）
+
+把样例村庄的**一类地面 + 一类角色**从程序绘制换成 CC0 真实像素素材，跑通接入管线；其余仍走
+原程序绘制图集 fallback。来源 / 许可 / sha256 完整记录见 `docs/素材来源.md`。
+
+- 构建（确定性，二次运行 byte-identical）：
+
+  ```bash
+  python3 scripts/make-cc0-art.py
+  # -> Assets/cc0-tiles.png       128x32  (4 个 32x32 地面格)
+  # -> Assets/cc0-characters.png 3840x48 (5 变体 x 4 向 x 6 帧, 32x48 格)
+  ```
+
+  同时修复了地块取样间距：源用无间距的 `tilemap_packed.png`（16px pitch），旧代码误按带间距
+  的 17px pitch 采样导致错格。
+- 开关：`LV_ASSET_PACK=cc0` 启用真实素材；未设置或其它值回退程序绘制江南图集。选择入口
+  `VillageArt.useCc0Pack` / `selectedGroundAtlasRelativePath` / `selectedCharacterAtlasRelativePath`。
+- 规格：源 16x16 / 16x24 整数 **2x NEAREST** → 32x32 / 32x48；加载尺寸与整数倍由
+  `src/LivingVillage.Desktop.Tests/AssetPackTests.fs` 断言（含开关与 fallback）。
+- 证据（`docs/evidence/`，被 .gitignore 命中故 `git add -f`；`check-no-white-blocks.py` 4 帧 0 命中）：
+  - `p33-atlas-day.png` / `p33-atlas-night.png`：样例村庄真实素材昼 / 夜整帧 1280x720。
+  - `p33-atlas-closeup-2x.png`：村庄地面 + 角色 2x NEAREST 特写（Kenney 草色 (78,151,76) 与
+    (132,198,105) 合计约 7.4 万像素，证实真素材上图）。
+  - `p33-atlas-baseline-day.png`：同场景程序绘制 fallback 对照（草色 (66,112,70)），与真实素材
+    帧明显不同（昼帧约 92% 像素差异）。
+- 复现：
+
+  ```bash
+  DLL=src/LivingVillage.Desktop/bin/Release/net8.0/LivingVillage.Desktop.dll
+  for h in 12.0 23.5; do
+    tag=day; [ "$h" = 23.5 ] && tag=night
+    timeout 20 xvfb-run -a -s "-screen 0 1280x720x24" env LV_AUTOPLAY_SAMPLE=1 \
+      LV_AUTOPLAY_RECORD=1 LV_AUTOPLAY_START_HOUR=$h LV_RECORD_EVERY=10 \
+      LV_RECORD_NAME=p33-$tag- LV_ASSET_PACK=cc0 \
+      LV_RECORD_DIR=/tmp/opencode/lv-p33-evidence/$tag dotnet "$DLL"
+  done
+  ```
+
+- 范围：本单只接入基础地块与一类角色；动画全套 / 全村 / 中式元素补绘留待后续切片。
diff --git a/scripts/make-cc0-art.py b/scripts/make-cc0-art.py
index f5c97ee..b26cba1 100644
--- a/scripts/make-cc0-art.py
+++ b/scripts/make-cc0-art.py
@@ -98,16 +98,19 @@ def verify_png(path, expected_w, expected_h):
 def build_cc0_tile_atlas():
     """Four 32x32 ground tiles from Kenney Tiny Farm, upscaled 2x.
 
-    Tile selection is fixed by grid coordinates chosen from the pack's
-    tilemap_packed.png (grass: two greens; stone path: pale slab; dirt: apricot).
+    Source is the *packed* sheet (tilemap_packed.png) which has NO spacing between
+    tiles: 192x176 = 12x11 tiles at a 16px pitch (the spaced tilemap.png is 203x186
+    at 17px pitch; mixing the two misaligns every non-zero cell). Tile selection is
+    fixed by grid coordinates: two full grass shades (9,8)/(10,8) for the checker
+    ground, then two grey stone slabs (4,8)/(4,9) for the paved path.
     """
     c = Canvas(128, 32)
     packed = Image.open(THIRD / "kenney_tiny-farm" / "Tilemap" / "tilemap_packed.png").convert("RGBA")
 
     def tile(grid_x, grid_y):
-        return packed.crop((grid_x * 17, grid_y * 17, grid_x * 17 + 16, grid_y * 17 + 16))
+        return packed.crop((grid_x * 16, grid_y * 16, grid_x * 16 + 16, grid_y * 16 + 16))
 
-    choices = [(10, 9), (9, 7), (6, 7), (6, 9)]
+    choices = [(9, 8), (10, 8), (4, 8), (4, 9)]
     for index, (gx, gy) in enumerate(choices):
         t = tile(gx, gy)
         c.blit(t, index * 32, 0, scale=2)
diff --git a/src/LivingVillage.Desktop.Tests/AssetPackTests.fs b/src/LivingVillage.Desktop.Tests/AssetPackTests.fs
new file mode 100644
index 0000000..fc235d0
--- /dev/null
+++ b/src/LivingVillage.Desktop.Tests/AssetPackTests.fs
@@ -0,0 +1,73 @@
+namespace LivingVillage.Desktop.Tests
+
+open System
+open System.IO
+open Microsoft.VisualStudio.TestTools.UnitTesting
+open LivingVillage.Kernel
+open LivingVillage.Kernel.Sim
+open LivingVillage.Desktop.VillageArt
+
+/// P33 vertical slice: the provenanced CC0 asset pack (Kenney Tiny Farm ground +
+/// Puny Characters) must load at the documented 32x32 / 32x48 shapes, be an exact
+/// integer 2x of the 16px / 16x24 source sprites, and stay behind the
+/// `LV_ASSET_PACK=cc0` switch so the procedural Jiangnan atlas is the fallback.
+[<TestClass>]
+type AssetPackTests () =
+
+    let assetPath (relative: string) =
+        Path.Combine(AppContext.BaseDirectory, relative)
+
+    let pngDimensions (path: string) : int * int =
+        let bytes = File.ReadAllBytes path
+        let signature = [| 0x89uy; 0x50uy; 0x4Euy; 0x47uy |]
+        for i in 0 .. 3 do
+            Assert.IsTrue(signature.[i] = bytes.[i], sprintf "%s is not a PNG" path)
+        let be32 (offset: int) =
+            (int bytes.[offset] <<< 24)
+            ||| (int bytes.[offset + 1] <<< 16)
+            ||| (int bytes.[offset + 2] <<< 8)
+            ||| int bytes.[offset + 3]
+        be32 16, be32 20
+
+    [<TestMethod>]
+    member _.Cc0GroundAtlasIsIntegerMultipleOfTheTileGrid () =
+        let width, height = pngDimensions (assetPath cc0TileAtlasRelativePath)
+        Assert.AreEqual<int>(cc0TileAtlasWidth, width)
+        Assert.AreEqual<int>(cc0TileAtlasHeight, height)
+        Assert.AreEqual<int>(0, width % Sim.tilePixels)
+        Assert.AreEqual<int>(0, height % Sim.tilePixels)
+        Assert.AreEqual<int>(4, width / Sim.tilePixels)
+        Assert.AreEqual<int>(2, Sim.tilePixels / cc0TileSourcePixels)
+        Assert.AreEqual<int>(0, Sim.tilePixels % cc0TileSourcePixels)
+
+    [<TestMethod>]
+    member _.Cc0CharacterAtlasIsIntegerMultipleOfTheCellGrid () =
+        let width, height = pngDimensions (assetPath cc0CharacterAtlasRelativePath)
+        Assert.AreEqual<int>(cc0CharacterAtlasWidth, width)
+        Assert.AreEqual<int>(cc0CharacterCellHeight, height)
+        Assert.AreEqual<int>(0, width % cc0CharacterCellWidth)
+        Assert.AreEqual<int>(0, height % cc0CharacterCellHeight)
+        Assert.AreEqual<int>(
+            cc0CharacterVariantCount * cc0CharacterDirectionCount * cc0CharacterFrameCount,
+            width / cc0CharacterCellWidth)
+        Assert.AreEqual<int>(2, cc0CharacterCellWidth / cc0CharacterSourceWidth)
+        Assert.AreEqual<int>(2, cc0CharacterCellHeight / cc0CharacterSourceHeight)
+
+    [<TestMethod>]
+    member _.AssetPackSwitchSelectsRealPackAndFallsBackToProcedural () =
+        let previous = Environment.GetEnvironmentVariable "LV_ASSET_PACK"
+        try
+            Environment.SetEnvironmentVariable("LV_ASSET_PACK", null)
+            Assert.IsFalse(useCc0Pack (), "unset switch must keep the procedural fallback")
+            Assert.IsTrue((selectedGroundAtlasRelativePath ()).IsNone, "fallback ground is procedural")
+            Assert.AreEqual<string>(characterAtlasRelativePath, selectedCharacterAtlasRelativePath ())
+
+            Environment.SetEnvironmentVariable("LV_ASSET_PACK", "cc0")
+            Assert.IsTrue(useCc0Pack (), "cc0 switch enables the real pack")
+            Assert.IsTrue(selectedGroundAtlasRelativePath () = Some cc0TileAtlasRelativePath)
+            Assert.AreEqual<string>(cc0CharacterAtlasRelativePath, selectedCharacterAtlasRelativePath ())
+
+            Environment.SetEnvironmentVariable("LV_ASSET_PACK", "kenney")
+            Assert.IsFalse(useCc0Pack (), "unknown pack value falls back to procedural")
+        finally
+            Environment.SetEnvironmentVariable("LV_ASSET_PACK", previous)
diff --git a/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj b/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj
index d4fa1f5..d32a21f 100644
--- a/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj
+++ b/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj
@@ -15,6 +15,7 @@
     <Compile Include="MapGenTests.fs" />
     <Compile Include="PerformanceSummaryTests.fs" />
     <Compile Include="M3BatchOutputTests.fs" />
+    <Compile Include="AssetPackTests.fs" />
     <Compile Include="SampleTests.fs" />
   </ItemGroup>
 
diff --git a/src/LivingVillage.Desktop/Assets/cc0-tiles.png b/src/LivingVillage.Desktop/Assets/cc0-tiles.png
index 1e43bc8..204eba2 100644
--- a/src/LivingVillage.Desktop/Assets/cc0-tiles.png
+++ b/src/LivingVillage.Desktop/Assets/cc0-tiles.png
diff --git a/src/LivingVillage.Desktop/VillageArt.fs b/src/LivingVillage.Desktop/VillageArt.fs
index 4faa886..9a034aa 100644
--- a/src/LivingVillage.Desktop/VillageArt.fs
+++ b/src/LivingVillage.Desktop/VillageArt.fs
@@ -544,22 +544,46 @@ module VillageArt =
         else
             texture
 
+    /// Fallback switch for the real-pixel asset pack (P33 vertical slice). When
+    /// `LV_ASSET_PACK=cc0`, the sample village swaps its ground + villager atlases for
+    /// the provenanced CC0 packs; any other value keeps the procedural Jiangnan atlases.
     let useCc0Pack () : bool =
         System.Environment.GetEnvironmentVariable("LV_ASSET_PACK") = "cc0"
 
     let cc0TileAtlasRelativePath = "Assets/cc0-tiles.png"
+    // Source ground tiles are 16x16, upscaled exactly 2x to one Sim.tilePixels cell.
+    let cc0TileSourcePixels = 16
     let cc0TileAtlasWidth = Sim.tilePixels * 4
+    let cc0TileAtlasHeight = Sim.tilePixels
     let cc0CharacterAtlasRelativePath = "Assets/cc0-characters.png"
+    // Source Puny band is 16x24, upscaled exactly 2x to a 32x48 cell; atlas packs
+    // 5 variants x 4 directions x 6 frames.
+    let cc0CharacterSourceWidth = 16
+    let cc0CharacterSourceHeight = 24
+    let cc0CharacterCellWidth = 32
+    let cc0CharacterCellHeight = 48
+    let cc0CharacterVariantCount = 5
+    let cc0CharacterDirectionCount = 4
+    let cc0CharacterFrameCount = 6
+    let cc0CharacterAtlasWidth =
+        cc0CharacterCellWidth * cc0CharacterVariantCount * cc0CharacterDirectionCount * cc0CharacterFrameCount
+
+    /// Ground atlas selection: `Some cc0-tiles.png` when the pack is on, else `None`
+    /// so the renderer keeps its procedural Jiangnan ground as the fallback.
+    let selectedGroundAtlasRelativePath () : string option =
+        if useCc0Pack () then Some cc0TileAtlasRelativePath else None
+
+    /// Character atlas selection: real CC0 Puny sprites when the pack is on, else the
+    /// procedural Jiangnan character atlas (fallback).
+    let selectedCharacterAtlasRelativePath () : string =
+        if useCc0Pack () then cc0CharacterAtlasRelativePath else characterAtlasRelativePath
 
     let loadTextures (device: GraphicsDevice) : ArtTextures =
         let cc0 =
-            if useCc0Pack () then
-                Some(loadTexture device cc0TileAtlasRelativePath cc0TileAtlasWidth Sim.tilePixels)
-            else
-                None
-        let characterPath = if useCc0Pack () then cc0CharacterAtlasRelativePath else characterAtlasRelativePath
+            selectedGroundAtlasRelativePath ()
+            |> Option.map (fun path -> loadTexture device path cc0TileAtlasWidth cc0TileAtlasHeight)
         { TileAtlas = loadTexture device worldAtlasRelativePath worldAtlasWidth worldAtlasHeight
-          CharacterAtlas = loadTexture device characterPath characterAtlasWidth characterAtlasHeight
+          CharacterAtlas = loadTexture device (selectedCharacterAtlasRelativePath ()) cc0CharacterAtlasWidth cc0CharacterCellHeight
           InteriorAtlas = loadTexture device interiorAtlasRelativePath interiorAtlasWidth interiorAtlasHeight
           Cc0TileAtlas = cc0 }