feat(client): UI primitives 基线（E2）

- 引入 Radix Dialog/DropdownMenu/Tabs + CVA
- 新增 Button/Input/Dialog/Tabs/Table/Card 等组件（本地拷贝单向同步）
- 增加 touch-target(44px) 样式基础

client/package.json

@@ -10,7 +10,12 @@
     "preview": "vite preview"
   },
   "dependencies": {
+    "@radix-ui/react-dialog": "^1.1.15",
+    "@radix-ui/react-dropdown-menu": "^2.1.16",
+    "@radix-ui/react-slot": "^1.2.4",
+    "@radix-ui/react-tabs": "^1.1.13",
     "@tanstack/react-query": "^5.62.0",
+    "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",