引入正文安全子集并收紧呈现创作口径，避免本局任意脚本美化。

创作只选壳与分区，渲染与提示共用同一份白名单语法。

Co-authored-by: Cursor <cursoragent@cursor.com>

src/skills/markdown-safe-subset.ts

@@ -0,0 +1,126 @@
+/**
+ * 正文 Markdown 安全子集目录。
+ * 正文组成执行时注入【正文安全子集】，与 web/markdown.js 实现对照维护。
+ */
+import { readFile } from "node:fs/promises";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { parse as parseYaml } from "yaml";
+
+const DEFAULT_SKILLS_ROOT = path.resolve(
+  path.dirname(fileURLToPath(import.meta.url)),
+  "../../skills",
+);
+
+export const MARKDOWN_SAFE_SUBSET_FILENAME =
+  "markdown-safe-subset/catalog.yaml";
+
+export type MarkdownSafeFeature = {
+  id: string;
+  name: string;
+  syntax: string;
+};
+
+export type MarkdownSafeSubsetCatalog = {
+  version: number;
+  intro: string;
+  features: MarkdownSafeFeature[];
+  restrictions: string[];
+};
+
+function asString(v: unknown): string {
+  return typeof v === "string" ? v.trim() : "";
+}
+
+export function parseMarkdownSafeSubsetCatalog(
+  raw: string,
+): MarkdownSafeSubsetCatalog | null {
+  let doc: unknown;
+  try {
+    doc = parseYaml(raw);
+  } catch {
+    return null;
+  }
+  if (!doc || typeof doc !== "object" || Array.isArray(doc)) return null;
+  const row = doc as Record<string, unknown>;
+  const featuresRaw = row.features;
+  if (!Array.isArray(featuresRaw)) return null;
+  const features: MarkdownSafeFeature[] = [];
+  for (const item of featuresRaw) {
+    if (!item || typeof item !== "object" || Array.isArray(item)) continue;
+    const f = item as Record<string, unknown>;
+    const id = asString(f.id);
+    const name = asString(f.name);
+    const syntax = asString(f.syntax);
+    if (!id || !name || !syntax) continue;
+    features.push({ id, name, syntax });
+  }
+  if (!features.length) return null;
+  const restrictions: string[] = [];
+  if (Array.isArray(row.restrictions)) {
+    for (const r of row.restrictions) {
+      const s = asString(r);
+      if (s) restrictions.push(s);
+    }
+  }
+  const version =
+    typeof row.version === "number" && Number.isFinite(row.version)
+      ? row.version
+      : 1;
+  return {
+    version,
+    intro: asString(row.intro),
+    features,
+    restrictions,
+  };
+}
+
+export async function loadMarkdownSafeSubsetCatalog(
+  skillPackRoot: string,
+  skillsRoot = DEFAULT_SKILLS_ROOT,
+): Promise<MarkdownSafeSubsetCatalog | null> {
+  const catalogPath = path.join(
+    skillsRoot,
+    skillPackRoot,
+    MARKDOWN_SAFE_SUBSET_FILENAME,
+  );
+  let raw: string;
+  try {
+    raw = await readFile(catalogPath, "utf8");
+  } catch {
+    return null;
+  }
+  return parseMarkdownSafeSubsetCatalog(raw);
+}
+
+export function formatMarkdownSafeSubsetForPrompt(
+  catalog: MarkdownSafeSubsetCatalog,
+): string {
+  const lines = [
+    "## 【正文安全子集】程序从仓库动态装载",
+    "",
+    catalog.intro ||
+      "用户开启 Markdown 渲染时，正文只吃下列语法；美化靠程序 class，勿写本局任意 CSS/HTML/JS。",
+    "",
+  ];
+  for (const f of catalog.features) {
+    lines.push(`- **${f.name}**（\`${f.id}\`）`);
+    const syn = f.syntax.trim();
+    if (syn.includes("\n")) {
+      lines.push("", "```", syn, "```", "");
+    } else {
+      lines.push(`  \`${syn}\``);
+    }
+  }
+  if (catalog.restrictions.length) {
+    lines.push("", "硬限制：");
+    for (const r of catalog.restrictions) {
+      lines.push(`- ${r}`);
+    }
+  }
+  lines.push(
+    "",
+    "区域「渲染提示」选 Markdown 时，只使用上表；日常折叠/表格走子集即可，一般不必填「渲染」里的 html/css/js。",
+  );
+  return lines.join("\n").trim();
+}