doc(web): update the chunk-layout note for the react-free vendor invariant and the audit tool

.agents/notes/implemented/architecture/2026-08-06-web-shell-dist-chunk-layout.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write .agents/notes/implemented/architecture/2026-08-06-web-shell-dist-chunk-layout.md
-2026-08-06-web-shell-dist-chunk-layout.md: bce46591d65bae2daa61b1d513b4bdf37a9fad20
-2026-08-06-web-shell-dist-chunk-layout.zh.md: 595338ddec4ff5a9926dafcf0b1181241dc51788
+2026-08-06-web-shell-dist-chunk-layout.md: 1c7b4273dc243685317b149e2fd7fddf2a6c18d1
+2026-08-06-web-shell-dist-chunk-layout.zh.md: 6f4b94e0bd7412e480458e34922273b389aa8892

.agents/notes/implemented/architecture/2026-08-06-web-shell-dist-chunk-layout.md

@@ -14,8 +14,9 @@ The apps/web shell previously built into a single ~1.2 MB (minified) index chunk
 
 **Membership** (`VENDOR_PACKAGES`, by exact npm package name):
 
-- `vendor` = the **facade packages** of the three heavy rendering families: math (katex, rehype-katex), highlight (shiki), markdown (react-markdown, remark-gfm, remark-math, mdast-util-from-markdown, mdast-util-gfm, micromark-extension-gfm, micromark-extension-math, micromark-factory-space, micromark-util-character, micromark-util-symbol, micromark-util-types). The list only needs the packages that workspace code **imports directly**: private transitive dependencies (the unified/hast family, the oniguruma family, @shikijs/core, and dozens more) are referenced only by these facades, so rollup's chunk coloring pulls them into vendor automatically; dependencies shared with the index side fall back to index, diluting it by a few KB — not a correctness issue.
-- `index` (the default chunk) = the react family, vendored cordis, all workspace code, and the unlisted small pieces (anser, clsx).
+- `vendor` = the three heavy rendering families: math (katex), highlight (shiki), markdown (the micromark/mdast parse pipeline — the incremental React renderer above it is workspace code and not part of this). The live membership is `VENDOR_PACKAGES`; the list is the packages workspace code **imports directly**: the remaining private transitive dependencies (the oniguruma family, @shikijs/core, character tables, dozens more) are referenced only by listed members, so rollup's chunk coloring pulls them into vendor automatically; dependencies shared with the index side fall back to index, diluting it by a few KB — not a correctness issue.
+- **Every vendor member must be react-free (the boundary invariant)**: rollup folds a module shared between the entry and a manual chunk into the manual chunk — one listed package importing react/jsx-runtime would drag the single shared react copy into vendor, away from index. The React side of markdown/math rendering is workspace code and naturally lives in index, so the whole react family stays pinned to index.
+- `index` (the default chunk) = the react family (react, react-dom, scheduler, use-sync-external-store), vendored cordis, all workspace code, and the unlisted small pieces (anser, clsx).
 - `@shikijs/langs` is special-cased: the boot grammars (`BOOT_GRAMMAR_FILES`: typescript, shellscript, json — the three that highlight.ts statically imports, all self-contained data modules with zero internal imports) go into vendor; the remaining 23 lazy-loaded grammars get no assignment and each keeps its own on-demand chunk.
 - `index.html` is wired up automatically by vite: index loads via `<script>` and vendor via `<link rel="modulepreload">`, so the two chunks fetch in parallel with no waterfall.
 
@@ -23,7 +24,7 @@ The apps/web shell previously built into a single ~1.2 MB (minified) index chunk
 
 - The `assets/` root keeps only the index and vendor js (with their adjacent sourcemaps) and css.
 - Grammar chunks go under `assets/langs/`. The criterion is whether a chunk's `moduleIds` include an `@shikijs/langs` member, not the facade: the shared chunks of embedded grammars (php/ruby/mdx embed html+javascript, which rollup splits out for sharing) **have no facade**, so a facade criterion would miss them; index and vendor are excluded by name, because vendor legitimately carries the three boot grammars.
-- Fonts go under `assets/fonts/` (`FONT_EXTENSIONS`: woff2/woff/ttf; today all of them are KaTeX faces referenced by vendor.css, and the browser fetches only woff2, on demand and only when a formula renders).
+- Fonts go under `assets/fonts/` (`FONT_EXTENSIONS`: woff2/woff/ttf; today all of them are KaTeX faces referenced by vendor.css — katex.min.css is imported by an index-side component, but CSS modules go through manualChunks like any module and follow `katex` into vendor.css; the browser fetches only woff2, on demand and only when a formula renders).
 - Sourcemaps need no arrangement: rollup writes each `.map` next to its js and references it by bare relative filename, so when a chunk moves directories its map follows automatically.
 
 All cross-directory references (index's dynamic imports into `langs/`, same-directory relative references among grammar chunks, vendor.css's relative references into `fonts/`) are emitted by the bundler, so the runtime needs zero accompanying changes; the host-side webserver serves the nested paths verbatim under its static prefix.
@@ -34,11 +35,12 @@ All cross-directory references (index's dynamic imports into `langs/`, same-dire
 - **An inverse catch-all rule (everything in node_modules except the react family goes to vendor)**: membership cannot be read off the configuration, and small pieces like anser/clsx get misassigned to vendor; superseded by the positive exact-package-name list.
 - **Regex family matching**: hard to read; exact package names plus rollup's automatic coloring of transitive dependencies make pattern matching unnecessary.
 - **Identifying grammar chunks by facadeModuleId**: the facade-less shared chunks of embedded grammars would go undetected and fall back to the root directory; the `moduleIds` membership criterion covers both shapes.
+- **Sheltering a react-edged rendering facade in vendor** (the historical react-markdown was one): rollup's shared-module folding would drag the single react copy into vendor, breaking the "react belongs to index" boundary; the constraint is codified as the list's boundary invariant.
 - **Lazy-loading KaTeX wholesale, or turning the boot TypeScript grammar lazy**: either would change first-frame rendering behavior (the fallback for formulas / the first code block); that trade-off is independent of the dist layout and is decided separately.
 
 ## Verification
 
-A sourcemap byte-attribution audit proves that vendor contains no workspace bytes and that the npm side of index retains only the react family plus anser/clsx; the lazy grammar chunk count matches the `LAZY_GRAMMARS` table one to one; the browser keyless replay case is verbatim-identical to the pre-change baseline (apart from environment-specific local reds), so the two-chunk shell loads and renders with no regression.
+The audit tool ships with the repository: `node scripts/attribute-chunk-bytes.mjs <chunk.js>` (zero-dependency sourcemap VLQ byte attribution, aggregated by npm package / workspace directory). It verifies that vendor contains no workspace bytes, that the react family (including react/jsx-runtime) sits entirely in index, and that the npm side of index retains only the react family plus anser/clsx; the lazy grammar chunk count matches the `LAZY_GRAMMARS` table one to one; the browser keyless replay case is verbatim-identical to the pre-change baseline (apart from environment-specific local reds), so the two-chunk shell loads and renders with no regression.
 
 ## Consequences
 

.agents/notes/implemented/architecture/2026-08-06-web-shell-dist-chunk-layout.zh.md

@@ -14,8 +14,9 @@ apps/web 的壳此前打成单一约 1.2 MB（minified）的 index chunk，其
 
 **成员归属**（`VENDOR_PACKAGES`，按精确 npm 包名）：
 
-- `vendor` = 三个重渲染家族的**门面包**：math（katex、rehype-katex）、highlight（shiki）、markdown（react-markdown、remark-gfm、remark-math、mdast-util-from-markdown、mdast-util-gfm、micromark-extension-gfm、micromark-extension-math、micromark-factory-space、micromark-util-character、micromark-util-symbol、micromark-util-types）。清单只需列 workspace 代码**直接 import** 的包：私有传递依赖（unified/hast 系、oniguruma 系、@shikijs/core 等数十个）只被这些门面引用，rollup 的 chunk 着色自动将其并入 vendor；与 index 侧共享的依赖回落 index，只稀释几 KB，不构成正确性问题。
-- `index`（默认 chunk）= react 族、vendored cordis、全部 workspace 代码及未列入的小件（anser、clsx）。
+- `vendor` = 三个重渲染家族：math（katex）、highlight（shiki）、markdown（micromark/mdast 解析管线——其上的增量 React 渲染器是 workspace 代码，不在此列）。成员以 `VENDOR_PACKAGES` 为活口径，清单 = workspace 代码**直接 import** 的包：其余私有传递依赖（oniguruma 系、@shikijs/core、字符表等数十个）只被清单成员引用，rollup 的 chunk 着色自动将其并入 vendor；与 index 侧共享的依赖回落 index，只稀释几 KB，不构成正确性问题。
+- **vendor 全员必须 react-free（边界不变量）**：rollup 会把入口与 manual chunk 共享的模块并入 manual chunk——清单里出现任何 import react/jsx-runtime 的包，唯一一份 react 副本就会被拽进 vendor、脱离 index。markdown/math 的 React 渲染侧是 workspace 代码天然住 index，react 族因此全部钉在 index。
+- `index`（默认 chunk）= react 族（react、react-dom、scheduler、use-sync-external-store）、vendored cordis、全部 workspace 代码及未列入的小件（anser、clsx）。
 - `@shikijs/langs` 特判：boot 语法（`BOOT_GRAMMAR_FILES`：typescript、shellscript、json——highlight.ts 静态 import 的三件，均为零内部 import 的自含数据模块）进 vendor；其余 23 个懒加载语法不做指派，各自保持按需 chunk。
 - `index.html` 由 vite 自动接线：index 走 `<script>`、vendor 走 `<link rel="modulepreload">`，两 chunk 并行拉取，无瀑布。
 
@@ -23,7 +24,7 @@ apps/web 的壳此前打成单一约 1.2 MB（minified）的 index chunk，其
 
 - `assets/` 根只留 index 与 vendor 的 js（含随行 sourcemap）与 css。
 - 语法 chunk 归 `assets/langs/`。判据是 chunk 的 `moduleIds` 含 `@shikijs/langs` 成员，而非 facade：内嵌语法共享 chunk（php/ruby/mdx 内嵌 html+javascript，被 rollup 拆出共享）**没有 facade**，facade 判据会漏；index/vendor 按名排除，因 vendor 合法携带 boot 三语法。
-- 字体归 `assets/fonts/`（`FONT_EXTENSIONS`：woff2/woff/ttf；今日全部为 vendor.css 引用的 KaTeX 字面，浏览器按需只拉 woff2，且仅在公式渲染时）。
+- 字体归 `assets/fonts/`（`FONT_EXTENSIONS`：woff2/woff/ttf；今日全部为 vendor.css 引用的 KaTeX 字面——katex.min.css 虽由 index 侧组件 import，css 模块同样经 manualChunks 归属、随 `katex` 落入 vendor.css；浏览器按需只拉 woff2，且仅在公式渲染时）。
 - sourcemap 无需安排：rollup 把 `.map` 写在各自 js 旁并以裸相对文件名引用，chunk 挪目录 map 自动跟随。
 
 跨目录引用（index 的动态 import 指向 `langs/`、语法 chunk 间同目录相对引用、vendor.css 相对引用 `fonts/`）均由构建器生成，运行时零配套改动；host 侧 webserver 按静态前缀原样服务嵌套路径。
@@ -34,11 +35,12 @@ apps/web 的壳此前打成单一约 1.2 MB（minified）的 index chunk，其
 - **反向兜底规则（node_modules 除 react 族全归 vendor）**：成员从配置上读不出来，且把 anser/clsx 类小件错归 vendor；被正向精确包名清单取代。
 - **正则家族匹配**：可读性差；精确包名 + rollup 对传递依赖的自动着色使模式匹配没有必要。
 - **以 facadeModuleId 识别语法 chunk**：无 facade 的内嵌语法共享 chunk 会漏检落回根目录；`moduleIds` 成员判据覆盖两种形态。
+- **在 vendor 里收留带 react 边的渲染门面**（历史上的 react-markdown 属此类）：会经 rollup 的共享模块归并把唯一 react 副本拽进 vendor，破坏「react 归 index」的边界；该约束已成文为清单的边界不变量。
 - **KaTeX 整体懒加载、boot TypeScript 语法转懒**：会改变首帧渲染行为（公式/首个代码块的回退），是独立于产物布局的取舍，另行决策。
 
 ## Verification
 
-sourcemap 字节归属审计证明 vendor 不含任何 workspace 字节、index 的 npm 侧仅剩 react 族与 anser/clsx；懒语法 chunk 数量与 `LAZY_GRAMMARS` 表一一对应；浏览器 keyless replay 用例与改动前基线逐字一致（本机环境性红除外），两 chunk 壳装载渲染无回归。
+审计工具随库：`node scripts/attribute-chunk-bytes.mjs <chunk.js>`（零依赖 sourcemap VLQ 字节归属，按 npm 包/workspace 目录聚合）。以其复核：vendor 不含任何 workspace 字节、react 族（含 react/jsx-runtime）全量位于 index、index 的 npm 侧仅剩 react 族与 anser/clsx；懒语法 chunk 数量与 `LAZY_GRAMMARS` 表一一对应；浏览器 keyless replay 用例与改动前基线逐字一致（本机环境性红除外），两 chunk 壳装载渲染无回归。
 
 ## Consequences