Add script to generate VitePress sidebar and frontmatter

This script processes SUMMARY.md to generate a collapsible sidebar for VitePress and ensures that all Markdown files have frontmatter.

.github/scripts/prepare.mjs

@@ -0,0 +1,62 @@
+import fs from 'node:fs'
+import path from 'node:path'
+
+const summary = fs.readFileSync('SUMMARY.md','utf8')
+const ROOT   = '.'
+fs.mkdirSync(path.join(ROOT,'.vitepress'),{recursive:true})
+
+function touch(mdPath){
+  fs.mkdirSync(path.dirname(mdPath),{recursive:true})
+  if (!fs.existsSync(mdPath)) fs.writeFileSync(mdPath,'# \n\n内容待补充。\n')
+}
+
+/* ===== 生成可折叠 sidebar ===== */
+const sidebar = []
+let stack     = [{ children: sidebar, level: -1 }] // 栈顶父节点
+const r       = /^(\s*)-\s+\[([^\]]+)\]\(([^)]+)\)/gm
+let m
+
+while ((m = r.exec(summary)) !== null) {
+  const [, sp, text, file] = m
+  const level = sp.length / 2
+  const url   = '/' + file.replace(/\.md$/,'')
+
+  // 找到父节点
+  while (level <= stack.at(-1).level) stack.pop()
+  const parent = stack.at(-1)
+
+  // 一级目录 → 折叠对象；子项直接 push
+  const node =
+    level === 0
+      ? { text, items: [{ text, link: url }], collapsed: true } // 默认折叠
+      : { text, link: url }
+
+  parent.children.push(node)
+
+  // 预留子级挂载点
+  if (level === 0) {
+    node.items = node.items || []
+    stack.push({ children: node.items, level })
+  } else {
+    stack.push({ children: parent.children, level })
+  }
+
+  touch(path.join(ROOT, file))
+}
+/* ================================= */
+
+// frontmatter 处理同上
+function walk(dir){
+  for (const f of fs.readdirSync(dir)){
+    const full = path.join(dir,f)
+    if (fs.statSync(full).isDirectory()){ walk(full); continue }
+    if (!f.endsWith('.md')) continue
+    const cnt = fs.readFileSync(full,'utf8')
+    if (!cnt.trimStart().startsWith('---'))
+      fs.writeFileSync(full, `---\n---\n${cnt}`)
+  }
+}
+walk(ROOT)
+
+fs.writeFileSync(path.join(ROOT,'.vitepress','sidebar.mjs'),
+  `export default ${JSON.stringify(sidebar,null,2)}`)