feat(saas): Phase 2 Admin Web 管理后台 — 完整 CRUD + Dashboard 统计

后端:
- 添加 GET /api/v1/stats/dashboard 聚合统计端点
  (账号数/活跃服务商/今日请求/今日Token用量等7项指标)
- 需要 account:admin 权限

Admin 前端 (Next.js 14 + shadcn/ui + Tailwind + Recharts):
- 设计系统: Dark Mode OLED (#020617 背景, #22C55E CTA)
- 登录页: 双栏布局, 品牌区 + 表单
- Dashboard 布局: Sidebar 导航 + Header + 主内容区
- 仪表盘: 4 统计卡片 + AreaChart 请求趋势 + BarChart Token用量
- 8 个 CRUD 页面:
  - 账号管理 (搜索/角色/状态筛选, 编辑/启用禁用)
  - 服务商 (CRUD + API Key masked)
  - 模型管理 (Provider筛选, CRUD)
  - API 密钥 (创建/撤销, 一次性显示token)
  - 用量统计 (LineChart + BarChart)
  - 中转任务 (状态筛选, 展开详情)
  - 系统配置 (分类Tab, 编辑)
  - 操作日志 (Action筛选, 展开详情)
- 14 个 shadcn 风格 UI 组件 (手写实现)
- 类型化 API 客户端 (SaaSClient, 20+ 方法, 401 自动跳转)
- AuthGuard 路由保护 + useAuth() hook

验证: tsc --noEmit 零 error, pnpm build 13 页面成功, cargo test 21 通过

admin/package.json

@@ -0,0 +1,37 @@
+{
+  "name": "zclaw-admin",
+  "version": "0.1.0",
+  "private": true,
+  "scripts": {
+    "dev": "next dev",
+    "build": "next build",
+    "start": "next start",
+    "lint": "next lint"
+  },
+  "dependencies": {
+    "@radix-ui/react-dialog": "^1.1.14",
+    "@radix-ui/react-select": "^2.2.5",
+    "@radix-ui/react-switch": "^1.2.5",
+    "@radix-ui/react-tabs": "^1.1.12",
+    "@radix-ui/react-tooltip": "^1.2.7",
+    "@radix-ui/react-separator": "^1.1.7",
+    "class-variance-authority": "^0.7.1",
+    "clsx": "^2.1.1",
+    "lucide-react": "^0.484.0",
+    "next": "14.2.29",
+    "react": "^18.3.1",
+    "react-dom": "^18.3.1",
+    "recharts": "^2.15.3",
+    "tailwind-merge": "^3.0.2"
+  },
+  "devDependencies": {
+    "@types/node": "^20.17.19",
+    "@types/react": "^18.3.18",
+    "@types/react-dom": "^18.3.5",
+    "autoprefixer": "^10.4.20",
+    "postcss": "^8.5.3",
+    "tailwindcss": "^3.4.17",
+    "typescript": "^5.7.3"
+  },
+  "packageManager": "pnpm@10.30.2"
+}