feat: 添加完整的前端管理系统 (VbenAdmin)

- 添加基于 VbenAdmin + Vue3 + Element Plus 的前端管理系统
- 包含完整的 UI 组件库和工具链
- 支持多应用架构 (web-ele, backend-mock, playground)
- 包含完整的开发规范和配置
- 修复 admin 目录的子模块问题，确保正确提交

admin/cspell.json

@@ -0,0 +1,68 @@
+{
+  "$schema": "https://raw.githubusercontent.com/streetsidesoftware/cspell/main/cspell.schema.json",
+  "version": "0.2",
+  "language": "en,en-US",
+  "allowCompoundWords": true,
+  "words": [
+    "acmr",
+    "antd",
+    "antdv",
+    "astro",
+    "brotli",
+    "clsx",
+    "defu",
+    "demi",
+    "echarts",
+    "ependencies",
+    "esno",
+    "etag",
+    "execa",
+    "iconify",
+    "iconoir",
+    "intlify",
+    "lockb",
+    "lucide",
+    "minh",
+    "minw",
+    "mkdist",
+    "mockjs",
+    "naiveui",
+    "nocheck",
+    "noopener",
+    "noreferrer",
+    "nprogress",
+    "nuxt",
+    "pinia",
+    "prefixs",
+    "publint",
+    "qrcode",
+    "shadcn",
+    "sonner",
+    "sortablejs",
+    "styl",
+    "taze",
+    "ui-kit",
+    "uicons",
+    "unplugin",
+    "unref",
+    "vben",
+    "vbenjs",
+    "vite",
+    "vitejs",
+    "vitepress",
+    "vnode",
+    "vueuse",
+    "yxxx"
+  ],
+  "ignorePaths": [
+    "**/node_modules/**",
+    "**/dist/**",
+    "**/*-dist/**",
+    "**/icons/**",
+    "pnpm-lock.yaml",
+    "**/*.log",
+    "**/*.test.ts",
+    "**/*.spec.ts",
+    "**/__tests__/**"
+  ]
+}