fix: 修复登出按钮无效 — 同时清除磁盘 cookie 和浏览器内存 context

- BrowserManager 新增 clearContext() 方法，关闭并丢弃平台 context
- deleteCookies 同时调用 cookieStore.delete + browser.clearContext
- 前端登出后直接 resetStatus，不再触发浏览器请求检查状态

web/src/hooks/useLoginStatus.ts

@@ -34,5 +34,11 @@ export function useLoginStatus(options: { auto?: boolean; intervalMs?: number }
     }
   }, [refresh, auto, intervalMs]);
 
-  return { status, error, loading, refresh };
+  const reset = useCallback(() => {
+    setStatus(null);
+    setError(null);
+    setLoading(false);
+  }, []);
+
+  return { status, error, loading, refresh, reset };
 }

web/src/pages/LoginPage.tsx

@@ -10,7 +10,7 @@ import { useToast } from '@/context/ToastContext';
 import { getLoginQRCode, deleteCookies, checkLoginCookie } from '@/api/endpoints';
 
 export function LoginPage() {
-  const { status, loading: statusLoading, refresh: refreshStatus } = useLoginStatus();
+  const { status, loading: statusLoading, refresh: refreshStatus, reset: resetStatus } = useLoginStatus();
   const { token } = useAuth();
   const { toast } = useToast();
 
@@ -96,7 +96,7 @@ export function LoginPage() {
       const res = await deleteCookies();
       if (res.success) {
         toast('success', '已成功登出');
-        void refreshStatus();
+        resetStatus();
       } else {
         toast('error', res.error?.message || '登出失败');
       }