feat(frontend): 认证体系 + 类型定义 + API 服务层

认证:
- AuthContext + useAuth (JWT token 持久化, 登录/登出)
- AdminLoginPage (登录表单, 对接 POST /auth/login)
- axios 拦截器自动注入 Authorization header
- 401 自动清除 token 并跳转登录页

类型:
- api.ts: TASK_STATUS 常量, TaskResponse/ProductScanResponse 扩展字段
- admin.ts: ProductResponse 扩展 + MaterialOption/BomItem

API 服务:
- authApi: login() + getMe()
- materialApi: fetchMaterialGroups() + fetchMaterialItems()
- printApi: getLabelPreview() + executePrint() + getPrinterConfig()
- antd 6.5.3 依赖

字体: simhei.ttf (标签打印用)

frontend/src/services/api.ts

@@ -8,11 +8,13 @@ const api = axios.create({
   },
 });
 
-// 请求拦截器 — 可在此注入 token
+// 请求拦截器 — 注入 JWT token
 api.interceptors.request.use(
   (config) => {
-    // const token = localStorage.getItem("access_token");
-    // if (token) config.headers.Authorization = `Bearer ${token}`;
+    const token = localStorage.getItem("track_admin_token");
+    if (token) {
+      config.headers.Authorization = `Bearer ${token}`;
+    }
     return config;
   },
   (error) => Promise.reject(error),
@@ -23,7 +25,12 @@ api.interceptors.response.use(
   (response) => response,
   (error) => {
     if (error.response?.status === 401) {
-      // 未授权：跳转登录 / 刷新 token
+      // Token 过期或无效 → 清除并跳转登录
+      localStorage.removeItem("track_admin_token");
+      localStorage.removeItem("track_admin_user");
+      if (window.location.pathname.startsWith("/admin")) {
+        window.location.href = "/admin/login";
+      }
     }
     return Promise.reject(error);
   },