feat(workspace): pin Jian submodule and shell wrapper deps (Step 1a Task 1)

Anchor v19 pivot at the workspace level: vendor Jian as a git submodule
pinned to fork commit ad13ce6 (P0.5 mini-gate GO; skia-safe 0.78 → 0.97 +
new pub draw_on_canvas adapter), wire jian-core / jian-skia / jian-host-desktop
as path deps with explicit version per spec §12.2, and re-export the
Jian render/geometry/scene types from shell-core so shell-native can
translate the OP RenderBackend facade into jian DrawOp commands.

shell-core stays wasm32-clean: only jian-core (already wasm32-validated
in P0.5) plus glam / bitflags / thiserror / tracing land here.
shell-native picks up the full P0-pinned GL stack (skia-safe 0.97.0,
glutin 0.32.3, glutin-winit 0.5.0, glow 0.17.0, winit 0.30.13,
raw-window-handle 0.6.2, scopeguard 1.2) plus jian-skia (textlayout)
and target-gated jian-host-desktop (default-features = false, no `run`
feature so we skip Jian's softbuffer raster present path — OP owns its
own GPU swap_buffers per spec §3.6).

Adds OP RenderBackend trait + Rect / Color (with RED/GREEN/BLUE/BLACK/
WHITE/TRANSPARENT named constants per spec §5.2) + TextLayout facade
that wraps jian_core::render::TextRun explicitly (TextRun has no Default
impl, fields enumerated to honour spec §5.2 round-2 CONCERN-1 fix).

Boundary checks all pass:
- wasm32 shell-web metadata: no jian-host-desktop / jian-skia
- aarch64-linux-android shell-native metadata: no jian-host-desktop
- shell-core src: no glutin / skia_safe / winit / glow imports

Tasks 2-4 (SharedSkiaContext + NativeBackend + ShellEvent mapping +
acceptance) follow per plan v7.

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "vendor/agent"]
 	path = vendor/agent
 	url = https://github.com/ZSeven-W/agent-rs.git
+[submodule "vendor/jian"]
+	path = vendor/jian
+	url = git@github.com:Kayshen-X/jian.git

Cargo.toml

@@ -6,6 +6,7 @@ resolver = "2"
 members = ["crates/*"]
 exclude = [
     "vendor/agent",
+    "vendor/jian",
     "node_modules",
 ]
 

crates/openpencil-shell-core/Cargo.toml

@@ -4,7 +4,7 @@ version.workspace = true
 edition.workspace = true
 rust-version.workspace = true
 license.workspace = true
-description = "OpenPencil shell — retained-mode widget tree, RenderBackend trait, parley + taffy (kickoff spec §1.2)"
+description = "OpenPencil shell — platform-agnostic widget facade + RenderBackend trait, Jian re-export wrapper (spec v19 §1.2 / §5.2)"
 
 [lib]
 name = "openpencil_shell_core"
@@ -12,11 +12,18 @@ path = "src/lib.rs"
 
 [dependencies]
 serde = { workspace = true, optional = true }
+thiserror = { workspace = true }
+tracing = { workspace = true }
 
-# Pinned per Task 0.4 wasm32 feature matrix verdict
-# (notes/2026-05-02-parley-wasm-feature-matrix.md "## 结论" 段)
-parley = { version = "0.2", default-features = false, features = ["std"] }
-taffy = { version = "0.6", default-features = false, features = ["std", "taffy_tree", "flexbox", "grid", "block_layout", "content_size"] }
+# v19 pivot: glam Vec2 用作 Point2D；bitflags 用于 widget facade 内部 flag。
+glam = { version = "0.29", default-features = false, features = ["std"] }
+bitflags = "2"
+
+# v19 pivot: re-export Jian render/geometry/scene types (spec §5.2 widget-facing facade
+# wraps jian-core; native-only deps live in shell-native, jian-core itself is wasm32-clean).
+# 双写 path + version per spec §12.2 ("path dep with explicit version") —— 防 cargo
+# 在不同 workspace context 下因 version 不一致退化到错版本。
+jian-core = { path = "../../vendor/jian/crates/jian-core", version = "0.0.1" }
 
 [features]
 default = []

crates/openpencil-shell-core/src/jian.rs

@@ -0,0 +1,41 @@
+//! Jian re-export module (spec v19 §2 / §1.2).
+//!
+//! `openpencil-shell-core` 是 Jian 薄 wrapper —— 把
+//! `jian_core::render::{DrawOp, Paint, TextRun, …}` 经 OP 层 re-export 给
+//! shell-native 内部翻译用。geometry / scene 类型加 `Jian*` 前缀，避免
+//! 与 OP 自有 `Rect` / `Color` (`render_backend.rs`) 冲突。
+//!
+//! **契约（spec §5.2.1 §746 行）**：v19 wrapper 在 NativeBackend impl 内
+//! **不让 widget code 直接看到 `jian_core::render::DrawOp`** —— widget 只
+//! 调 OP `RenderBackend` method。这些 re-export 是给 **shell-native 内部**
+//! 翻译用，不是给 widget code 用。
+
+// ────────────────────────────────────────────────────────────────────────────
+// jian_core::render —— DrawOp 命令缓冲 + Paint / TextRun / 其它绘图描述符
+// ────────────────────────────────────────────────────────────────────────────
+
+pub use jian_core::render::{
+    BorderRadii, DrawOp, GradientStop, ImageSource, LinearGradient, Paint, PathCommand,
+    RadialGradient, RenderCommand, ShadowSpec, StrokeOp, TextAlign, TextRun,
+};
+
+// ────────────────────────────────────────────────────────────────────────────
+// jian_core::geometry —— 加 Jian* 前缀避免与 OP `Rect` 冲突
+// ────────────────────────────────────────────────────────────────────────────
+
+/// Jian 的 axis-aligned 矩形 (`euclid::Rect<f32>`)。
+/// OP 自有 `crate::render_backend::Rect` 是 widget facade 用；shell-native
+/// 内部翻译时把 OP `Rect` → `JianRect`（`origin/size` → `euclid::Rect::new`）。
+pub type JianRect = jian_core::geometry::Rect;
+pub type Size = jian_core::geometry::Size;
+pub type JianPoint = jian_core::geometry::Point;
+pub type Affine2 = jian_core::geometry::Affine2;
+
+// ────────────────────────────────────────────────────────────────────────────
+// jian_core::scene —— Color (packed u32) 加 Jian* 前缀
+// ────────────────────────────────────────────────────────────────────────────
+
+/// Jian 的 packed-RGBA 颜色 (`pub struct Color(pub u32)`)；与 OP
+/// `crate::render_backend::Color` (RGBA f32 quad) 不同。NativeBackend 内部
+/// 翻译 OP Color → JianColor 时用位打包。
+pub type JianColor = jian_core::scene::Color;

crates/openpencil-shell-core/src/lib.rs

@@ -1,20 +1,18 @@
-//! OpenPencil shell core — platform-agnostic widget tree + render-backend trait.
+//! OpenPencil shell core — platform-agnostic widget facade + RenderBackend trait.
 //!
-//! Per kickoff spec §1.2 (FROZEN 2026-05-02): this crate must compile on
+//! Per spec v19 §1.2 (FROZEN 2026-05-04): this crate must compile on
 //! wasm32-unknown-unknown. winit / accesskit_winit / skia-safe live in
 //! `openpencil-shell-native`; wasm-bindgen / web-sys / CanvasKit live in
 //! `openpencil-shell-web`.
+//!
+//! v19 pivot — 该 crate 是 Jian 薄 wrapper：
+//! - [`jian`] 模块 re-export `jian_core::render::{DrawOp, Paint, TextRun, …}`
+//!   + geometry/scene aliases，给 shell-native 内部翻译用（widget code 看不到）。
+//! - [`render_backend`] 模块定义 OP 自有 widget-facing facade
+//!   (`RenderBackend` trait + `Rect` / `Color` / `TextLayout`，spec §5.2)。
 
-pub fn placeholder() -> &'static str {
-    "openpencil-shell-core skeleton"
-}
+pub mod jian;
+pub mod render_backend;
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn skeleton_returns_string() {
-        assert_eq!(placeholder(), "openpencil-shell-core skeleton");
-    }
-}
+// Re-export 主要 API 给上层 crate / widgets / tests 用。
+pub use render_backend::{Color, Point2D, Rect, RenderBackend, TextLayout};

crates/openpencil-shell-core/src/render_backend.rs

@@ -0,0 +1,181 @@
+//! OP `RenderBackend` widget-facing facade (spec v19 §5.2).
+//!
+//! 这是 OP 的设计契约（method-style API：`fill_rect / stroke_rect / draw_text /
+//! clip_rect / save / restore / translate / resize / dpi_scale`），与 Jian
+//! `jian_core::render::RenderBackend`（command-buffer style，`new_surface /
+//! begin_frame / draw(&DrawOp)` etc.）不直接重合。
+//!
+//! 实现路径 (per §5.2.1)：
+//! - `NativeBackend` (shell-native, Step 1a 起 frame-scoped 设计)：**不**直接
+//!   impl 该 trait，而是 expose 同名 method 但带 `canvas: &skia_safe::Canvas`
+//!   显式参数。Step 1a basic_window demo 通过 `SharedSkiaContext::with_frame`
+//!   闭包内调 NativeBackend method。Step 1c+ 真接入 widget tree 时再考虑用
+//!   `WithCanvas<'a>` newtype 把 canvas 注入 trait impl。
+//! - `WebCanvasKitBackend` (shell-web, Step 1b)：内部用 CanvasKit JS binding。
+//! - `MobileBackend` (Step 1f)：内部用 Metal / Vulkan / OpenGL ES。
+//!
+//! 该模块**不**引 skia-safe / Canvas / GL 类型 —— shell-core 必须 wasm32-clean
+//! (per spec §1.2 boundary)。
+
+use jian_core::render::{TextAlign, TextRun};
+
+/// 2D 坐标点（spec §5.2 钉死 `glam::Vec2`）。
+pub type Point2D = glam::Vec2;
+
+/// 矩形（origin + size 双 Vec2 表示）。
+#[derive(Debug, Clone, Copy)]
+pub struct Rect {
+    pub origin: Point2D,
+    pub size: Point2D,
+}
+
+/// RGBA color（widget facade 层；所有分量 0.0..=1.0）。
+///
+/// 命名常量定义在 OP 这层（spec v19 round 5 CONCERN-R5-3 fix）；
+/// `jian_core::scene::Color` 是 `Color(pub u32)` packed RGBA，没有
+/// RED/BLACK/etc 命名常量，调用方用 `JianColor::rgb(...)` 显式构造。
+#[derive(Debug, Clone, Copy)]
+pub struct Color {
+    pub r: f32,
+    pub g: f32,
+    pub b: f32,
+    pub a: f32,
+}
+
+impl Color {
+    pub const RED: Self = Self {
+        r: 1.0,
+        g: 0.0,
+        b: 0.0,
+        a: 1.0,
+    };
+    pub const GREEN: Self = Self {
+        r: 0.0,
+        g: 1.0,
+        b: 0.0,
+        a: 1.0,
+    };
+    pub const BLUE: Self = Self {
+        r: 0.0,
+        g: 0.0,
+        b: 1.0,
+        a: 1.0,
+    };
+    pub const BLACK: Self = Self {
+        r: 0.0,
+        g: 0.0,
+        b: 0.0,
+        a: 1.0,
+    };
+    pub const WHITE: Self = Self {
+        r: 1.0,
+        g: 1.0,
+        b: 1.0,
+        a: 1.0,
+    };
+    pub const TRANSPARENT: Self = Self {
+        r: 0.0,
+        g: 0.0,
+        b: 0.0,
+        a: 0.0,
+    };
+}
+
+/// OP 的 TextLayout —— v19 删 parley 后定义在 OP 这层；薄薄包装
+/// `jian_core::render::TextRun`。
+///
+/// 不持 layout context / glyph cache（shell-core wasm32-clean，不能引
+/// skia/parley/icu）；真 layout 在 NativeBackend::draw_text 时通过
+/// `jian_skia::SkiaBackend` 的 textlayout feature（skia textlayout,
+/// ICU+harfbuzz）做 shape + line break。
+///
+/// Step 1a TextLayout 仅作 "已 shape 的 TextRun 集合" 占位；
+/// caret/selection/bidi/wrap 推 Step 1c+。signatures 钉死，避免后续 Step
+/// API break。
+#[derive(Debug, Clone)]
+pub struct TextLayout {
+    runs: Vec<TextRun>,
+}
+
+impl TextLayout {
+    /// 单 run 构造（Step 1a 唯一活跃路径；Phase B/C demo + raster_text_smoke 用）。
+    ///
+    /// 字段对齐 `jian_core::render::TextRun` (`vendor/jian/crates/jian-core/src/render/paint.rs:77-94`)：
+    /// **TextRun 没有 `Default` impl**，必须显式构造所有字段。
+    /// - `content` / `font_family` / `font_size` / `color` / `origin`：调用方传入
+    /// - `font_weight: 400` (CSS Normal)
+    /// - `max_width: 0.0`（"unknown; render at origin with no alignment adjustment"）
+    /// - `align: TextAlign::Start`
+    /// - `line_height: 0.0`（"default"）
+    pub fn single_run(
+        content: &str,
+        font_family: &str,
+        font_size: f32,
+        color: jian_core::scene::Color,
+        origin: Point2D,
+    ) -> Self {
+        let run = TextRun {
+            content: content.to_string(),
+            font_family: font_family.to_string(),
+            font_size,
+            font_weight: 400,
+            color,
+            origin: jian_core::geometry::Point::new(origin.x, origin.y),
+            max_width: 0.0,
+            align: TextAlign::Start,
+            line_height: 0.0,
+        };
+        Self { runs: vec![run] }
+    }
+
+    /// 已 shape 的 TextRun 集合视图。
+    pub fn runs(&self) -> &[TextRun] {
+        &self.runs
+    }
+
+    /// 平移所有 run 的 origin（NativeBackend::draw_text 在 widget origin
+    /// 基础上做平移）。返回新 layout，原 layout 不动。
+    pub fn translated(&self, offset: Point2D) -> Self {
+        let runs = self
+            .runs
+            .iter()
+            .map(|r| {
+                let mut r2 = r.clone();
+                r2.origin =
+                    jian_core::geometry::Point::new(r.origin.x + offset.x, r.origin.y + offset.y);
+                r2
+            })
+            .collect();
+        Self { runs }
+    }
+}
+
+/// Backend 抽象（widget-facing facade，spec §5.2）。
+///
+/// 注：trait 不加 `Send` bound —— skia-safe 类型 `!Send`（rust-skia
+/// thread-bound），Backend 在 render thread 内单独使用，无跨线程需求。
+///
+/// `NativeBackend` (shell-native) 在 1a **不**直接 impl 该 trait（v19 round 3
+/// BLOCK-R3-3 fix —— frame-scoped 设计避免跨帧 borrow），而是 expose 同名
+/// method 但带 `canvas: &skia_safe::Canvas` 显式参数。trait 签名内不出现任何
+/// Skia / GPU-backend 特定类型。
+pub trait RenderBackend {
+    /// Begin 帧，backend 内部维护 current frame state（不暴露 canvas 类型）。
+    fn begin_frame(&mut self);
+    fn end_frame(&mut self);
+
+    // 绘图 primitives —— widgets 调这些，不直接操作 canvas。
+    fn fill_rect(&mut self, rect: Rect, color: Color);
+    fn stroke_rect(&mut self, rect: Rect, color: Color, width: f32);
+    fn draw_text(&mut self, layout: &TextLayout, origin: Point2D);
+    fn clip_rect(&mut self, rect: Rect);
+
+    // 变换栈。
+    fn save(&mut self);
+    fn restore(&mut self);
+    fn translate(&mut self, offset: Point2D);
+
+    // viewport / dpi。
+    fn resize(&mut self, width: u32, height: u32);
+    fn dpi_scale(&self) -> f32;
+}

crates/openpencil-shell-core/tests/jian_re_export.rs

@@ -0,0 +1,87 @@
+//! Task 1 Step 20-21: prove the Jian re-export wrapper compiles & is usable.
+//!
+//! Two anchor invariants for spec v19 §2 / §5.2：
+//! 1. `DrawOp::Rect` constructible **through OP re-export path**
+//!    (`openpencil_shell_core::jian::DrawOp` —— shell-native 内部翻译用)。
+//! 2. `TextLayout::single_run` 产生**恰好一个** `TextRun`（spec §5.2，
+//!    确认 `..Default::default()` 替代成显式字段后语义等价）。
+
+use openpencil_shell_core::jian::{DrawOp, JianRect, Paint};
+use openpencil_shell_core::render_backend::{Color, Point2D, TextLayout};
+
+#[test]
+fn drawop_rect_constructible_via_re_export() {
+    // 通过 OP re-export 路径构造 Jian DrawOp::Rect —— 证明 shell-core 的
+    // jian 模块把 jian_core::render::{DrawOp, Paint} 暴露出来了。
+    let rect = JianRect::new(
+        jian_core::geometry::Point::new(0.0, 0.0),
+        jian_core::geometry::Size::new(100.0, 50.0),
+    );
+    let paint = Paint::solid(jian_core::scene::Color::rgb(255, 0, 0));
+    let op = DrawOp::Rect { rect, paint };
+
+    match op {
+        DrawOp::Rect { rect, .. } => {
+            assert_eq!(rect.size.width, 100.0);
+            assert_eq!(rect.size.height, 50.0);
+        }
+        _ => panic!("expected DrawOp::Rect"),
+    }
+}
+
+#[test]
+fn text_layout_single_run_creates_one_run() {
+    // 显式字段构造（TextRun 没 Default impl）—— 证明 spec §5.2 的
+    // single_run 路径产生恰好一个 run，content/font_family/font_size
+    // 都按调用方传入设置。
+    let layout = TextLayout::single_run(
+        "Hello",
+        "system-ui",
+        16.0,
+        jian_core::scene::Color::rgb(0, 0, 0),
+        Point2D::new(10.0, 20.0),
+    );
+
+    assert_eq!(layout.runs().len(), 1);
+
+    let run = &layout.runs()[0];
+    assert_eq!(run.content, "Hello");
+    assert_eq!(run.font_family, "system-ui");
+    assert_eq!(run.font_size, 16.0);
+    assert_eq!(run.font_weight, 400);
+    assert_eq!(run.origin.x, 10.0);
+    assert_eq!(run.origin.y, 20.0);
+    assert_eq!(run.max_width, 0.0);
+    assert_eq!(run.line_height, 0.0);
+}
+
+#[test]
+fn text_layout_translated_offsets_origin() {
+    // translated() 把 offset 加到每 run origin 上；原 layout 不变。
+    let layout = TextLayout::single_run(
+        "World",
+        "system-ui",
+        14.0,
+        jian_core::scene::Color::rgb(0, 0, 0),
+        Point2D::new(5.0, 10.0),
+    );
+    let shifted = layout.translated(Point2D::new(100.0, 200.0));
+
+    assert_eq!(shifted.runs()[0].origin.x, 105.0);
+    assert_eq!(shifted.runs()[0].origin.y, 210.0);
+
+    // 原 layout 不动
+    assert_eq!(layout.runs()[0].origin.x, 5.0);
+    assert_eq!(layout.runs()[0].origin.y, 10.0);
+}
+
+#[test]
+fn op_color_constants_distinct() {
+    // spec §5.2 命名常量 6 全 —— RED/GREEN/BLUE/BLACK/WHITE/TRANSPARENT。
+    assert_eq!(Color::RED.r, 1.0);
+    assert_eq!(Color::GREEN.g, 1.0);
+    assert_eq!(Color::BLUE.b, 1.0);
+    assert_eq!(Color::BLACK.r, 0.0);
+    assert_eq!(Color::WHITE.r, 1.0);
+    assert_eq!(Color::TRANSPARENT.a, 0.0);
+}

crates/openpencil-shell-native/Cargo.toml

@@ -4,7 +4,7 @@ version.workspace = true
 edition.workspace = true
 rust-version.workspace = true
 license.workspace = true
-description = "OpenPencil shell — native (winit + skia-safe + accesskit) backend"
+description = "OpenPencil shell — native (winit + skia-safe + accesskit) backend, integrating jian-skia + jian-host-desktop sub-pieces (spec v19 §3 / §5.2.1)"
 
 [lib]
 name = "openpencil_shell_native"
@@ -17,17 +17,37 @@ openpencil-shell-core = { path = "../openpencil-shell-core", version = "0.1.0" }
 # 如果不 cfg-gate，cargo 会先 fetch + run skia-safe 的 build.rs（在 wasm32 上构建失败），
 # Step 5 grep `must NOT be compiled for wasm32` 永远命中不到——会被 skia 错误盖过。
 #
-# Phase 1 skeleton 阶段：故意保持 deps 最小，仅声明意图所需的核心 crate（winit）。
-# skia-safe / accesskit / accesskit_winit 等在 Stage F 真正实现 RenderBackend 时再加。
-# 原因：Rust 1.80 toolchain (rust-toolchain.toml) 对 home/hashbrown 等 crate 当前
-# 版本的 edition2024 / MSRV 1.81+ 需求不兼容，加完整依赖会导致下载阶段失败。
-# 详见提交说明 + Phase 1 Gate codex review。
+# v19 pivot (Task 1): 加 P0-pinned GL stack + jian-skia + jian-host-desktop。
+#   - P0 dep-stack pin 来自 P0 probe（plan v7 §Task P0；skia-safe 0.97 + glow 0.17 +
+#     glutin 0.32.3 + glutin-winit 0.5.0 + winit 0.30.13 + raw-window-handle 0.6.2 +
+#     scopeguard 1.2 全在 macOS/Windows/Linux GO）。
+#   - jian-skia (textlayout feature) 提供 SkiaBackend impl + skia textlayout（替代 parley）。
+#   - jian-host-desktop (target-gate desktop only, 不含 `run` feature) 复用 PointerTranslator /
+#     scene::collect_draws_with_state / DesktopHost config helpers；OP 自管 GPU event loop，
+#     不调 jian_host_desktop::run（softbuffer raster present 不需要）。
 #
 # winit features 说明：on Linux 必须显式开 `x11` 和/或 `wayland`，否则
-# `platform_impl/mod.rs` 触发 `compile_error!("The platform you're compiling for is
-# not supported by winit")`. macOS / Windows 各自的 backend 通过 cfg(target_os)
-# 默认启用，不需要 feature flag。Step 1a 只在三大桌面 OS 跑 CI，所以同时打开
-# x11 + wayland 两个 Linux backend 就够。Stage F 真正接 RenderBackend 时会
-# 重新审视（可能加 `serde` / `rwh_06` 等）。
+# `platform_impl/mod.rs` 触发 `compile_error!`. macOS / Windows 各自的 backend 通过
+# cfg(target_os) 默认启用，不需要 feature flag。Step 1a 三大桌面 OS CI 都跑，
+# 所以同时打开 x11 + wayland 两个 Linux backend 就够。
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
-winit = { version = "0.30", default-features = false, features = ["x11", "wayland", "wayland-csd-adwaita", "rwh_06"] }
+skia-safe = { version = "0.97.0", features = ["gl"] }
+glutin = "0.32.3"
+glutin-winit = "0.5.0"
+glow = "0.17.0"
+winit = { version = "0.30.13", default-features = false, features = ["x11", "wayland", "wayland-csd-adwaita", "rwh_06"] }
+raw-window-handle = "0.6.2"
+scopeguard = "1.2"
+
+# Jian path deps —— 双写 path + version per spec §12.2。
+# jian-skia: 提供 SkiaBackend (RenderBackend impl) + skia textlayout (textlayout feature
+# 需要 ICU + harfbuzz, ~15MB；P0.5 已升 skia-safe 0.78→0.97 + 新增 pub draw_on_canvas).
+jian-skia = { path = "../../vendor/jian/crates/jian-skia", version = "0.0.1", features = ["textlayout"] }
+
+# jian-host-desktop: target-gate desktop only (Linux/macOS/Windows)；不进 android/ios
+# metadata（Task 1 Step 26 boundary check 验证）。
+# - default-features = false：Jian 默认 features 含 `run = ["dep:softbuffer"]` 拉
+#   raster present；OP 自管 GPU event loop 不需要 softbuffer。
+# - features = ["textlayout"]：与 jian-skia 对齐文本路径。
+[target.'cfg(any(target_os = "macos", target_os = "linux", target_os = "windows"))'.dependencies]
+jian-host-desktop = { path = "../../vendor/jian/crates/jian-host-desktop", version = "0.0.1", default-features = false, features = ["textlayout"] }

crates/openpencil-shell-native/src/lib.rs

@@ -1,20 +1,27 @@
 //! OpenPencil shell — native (desktop) backend.
 //!
-//! Per kickoff spec §1.2: this crate must NOT be linked into the wasm32-unknown-unknown
-//! web bundle. Even though some deps (winit) compile silently on wasm32 via web-sys,
-//! we use an explicit compile_error! guard to make accidental inclusion a hard error.
+//! Per spec v19 §1.2 (FROZEN 2026-05-04): this crate must NOT be linked into
+//! the wasm32-unknown-unknown web bundle. Even though some deps (winit) compile
+//! silently on wasm32 via web-sys, we use an explicit compile_error! guard to
+//! make accidental inclusion a hard error.
+//!
+//! Step 1a Task 1 状态：仅装 deps（P0-pinned GL stack + jian-skia +
+//! jian-host-desktop）；SharedSkiaContext / NativeBackend 实现在 Task 2 加。
 
 #[cfg(target_arch = "wasm32")]
 compile_error!(
     "openpencil-shell-native must NOT be compiled for wasm32 targets. \
-     Use openpencil-shell-web for browser builds (kickoff spec §1.2)."
+     Use openpencil-shell-web for browser builds (spec v19 §1.2)."
 );
 
-pub fn placeholder() -> String {
-    format!(
-        "openpencil-shell-native skeleton ({})",
-        openpencil_shell_core::placeholder()
-    )
+/// Skeleton placeholder until Task 2 lands `SharedSkiaContext` / `NativeBackend`.
+///
+/// 用 OP `Color::RED` 命名常量证明 shell-core re-export 链通了；这是最小
+/// link-check （Step 1a Task 1 不实现 Skia surface 与 GL provider，那些
+/// 是 Task 2 的范围）。
+pub fn placeholder() -> &'static str {
+    let _red = openpencil_shell_core::Color::RED;
+    "openpencil-shell-native skeleton (Task 1: deps wired)"
 }
 
 #[cfg(test)]
@@ -23,6 +30,6 @@ mod tests {
 
     #[test]
     fn skeleton_links_core() {
-        assert!(placeholder().contains("openpencil-shell-core"));
+        assert!(placeholder().contains("Task 1"));
     }
 }

crates/openpencil-shell-web/src/lib.rs

@@ -1,15 +1,21 @@
 //! OpenPencil shell — web (wasm32) bundle entry.
 //!
-//! Per kickoff spec §1.2: this crate is the web bundle entry. CI invariant
-//! requires `cargo check --target wasm32-unknown-unknown -p openpencil-shell-web
-//! --no-default-features --features web` to pass on every PR.
+//! Per spec v19 §1.2 (FROZEN 2026-05-04): this crate is the web bundle entry.
+//! CI invariant requires `cargo check --target wasm32-unknown-unknown -p
+//! openpencil-shell-web --no-default-features --features web` to pass on
+//! every PR.
+//!
+//! Step 1a Task 1 状态：仅 link-check shell-core re-export；CanvasKit
+//! WebBackend 在 Step 1b 加。
 
 use wasm_bindgen::prelude::*;
 
+/// Skeleton placeholder until Step 1b lands `WebCanvasKitBackend`.
+///
+/// 用 OP `Color::TRANSPARENT` 命名常量证明 shell-core re-export 在 wasm32
+/// 链通了；这是最小 link-check（shell-core 必须 wasm32-clean per spec §1.2）。
 #[wasm_bindgen]
 pub fn placeholder() -> String {
-    format!(
-        "openpencil-shell-web skeleton ({})",
-        openpencil_shell_core::placeholder()
-    )
+    let _t = openpencil_shell_core::Color::TRANSPARENT;
+    "openpencil-shell-web skeleton (Task 1: deps wired)".to_string()
 }

vendor/jian

@@ -0,0 +1 @@
+Subproject commit ad13ce6283caf402e71608d362e837b09140331b