chore: 初始化前端仓库并迁移 admin-ui

- 创建 rui-frontend 前端仓库
- 迁移 admin-ui 管理后台
- 创建 cashier-mobile 和 customer-mobile 占位项目
- 配置 pnpm workspace

admin-ui/tsconfig.json

@@ -0,0 +1,21 @@
+{
+  "compilerOptions": {
+    "target": "ESNext",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "strict": true,
+    "jsx": "preserve",
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "skipLibCheck": true,
+    "noEmit": true,
+    "baseUrl": ".",
+    "paths": {
+      "@/*": ["src/*"]
+    },
+    "types": ["vite/client"]
+  },
+  "include": ["src/**/*.ts", "src/**/*.vue", "src/**/*.d.ts", "src/types/**/*.d.ts"]
+}