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/packages/@core/base/icons/src/create-icon.ts

@@ -0,0 +1,14 @@
+import { defineComponent, h } from 'vue';
+
+import { Icon } from '@iconify/vue';
+
+function createIconifyIcon(icon: string) {
+  return defineComponent({
+    name: `Icon-${icon}`,
+    setup(props, { attrs }) {
+      return () => h(Icon, { icon, ...props, ...attrs });
+    },
+  });
+}
+
+export { createIconifyIcon };

admin/packages/@core/base/icons/src/index.ts

@@ -0,0 +1,11 @@
+export * from './create-icon';
+
+export * from './lucide';
+
+export type { IconifyIcon as IconifyIconStructure } from '@iconify/vue';
+export {
+  addCollection,
+  addIcon,
+  Icon as IconifyIcon,
+  listIcons,
+} from '@iconify/vue';

admin/packages/@core/base/icons/src/lucide.ts

@@ -0,0 +1,68 @@
+export {
+  ArrowDown,
+  ArrowLeft,
+  ArrowLeftToLine,
+  ArrowRightLeft,
+  ArrowRightToLine,
+  ArrowUp,
+  ArrowUpToLine,
+  Bell,
+  BookOpenText,
+  Check,
+  ChevronDown,
+  ChevronLeft,
+  ChevronRight,
+  ChevronsLeft,
+  ChevronsRight,
+  Circle,
+  CircleAlert,
+  CircleCheckBig,
+  CircleHelp,
+  CircleX,
+  Copy,
+  CornerDownLeft,
+  Ellipsis,
+  Expand,
+  ExternalLink,
+  Eye,
+  EyeOff,
+  FoldHorizontal,
+  Fullscreen,
+  Github,
+  Grip,
+  GripVertical,
+  Menu as IconDefault,
+  Info,
+  InspectionPanel,
+  Languages,
+  LoaderCircle,
+  LockKeyhole,
+  LogOut,
+  MailCheck,
+  Maximize,
+  ArrowRightFromLine as MdiMenuClose,
+  ArrowLeftFromLine as MdiMenuOpen,
+  Menu,
+  Minimize,
+  Minimize2,
+  MoonStar,
+  Palette,
+  PanelLeft,
+  PanelRight,
+  Pin,
+  PinOff,
+  Plus,
+  RotateCw,
+  Search,
+  SearchX,
+  Settings,
+  Shrink,
+  Square,
+  SquareCheckBig,
+  SquareMinus,
+  Sun,
+  SunMoon,
+  SwatchBook,
+  UserRoundPen,
+  X,
+} from 'lucide-vue-next';