fix(frontend): prevent redirect to dashboard on page refresh

Fix hydration race condition where token check happened before
localStorage was read. Now waits for client-side initialization
before deciding whether to redirect to login.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/mining-admin-web/src/app/(dashboard)/layout.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import { useEffect } from 'react';
+import { useEffect, useState } from 'react';
 import { useRouter } from 'next/navigation';
 import { useAppDispatch, useAppSelector } from '@/store/hooks';
 import { getProfile } from '@/store/slices/auth.slice';
@@ -15,17 +15,34 @@ export default function DashboardLayout({ children }: { children: React.ReactNod
   const dispatch = useAppDispatch();
   const { token, isAuthenticated, user } = useAppSelector((state) => state.auth);
   const { isCollapsed } = useSidebar();
+  const [isInitialized, setIsInitialized] = useState(false);
+
+  // 等待客户端 hydration 完成后再检查 token
+  useEffect(() => {
+    // 在客户端检查 localStorage 中是否有 token
+    const storedToken = localStorage.getItem('admin_token');
+    if (!storedToken) {
+      // 确实没有 token，跳转到登录页
+      router.push('/login');
+    } else {
+      setIsInitialized(true);
+    }
+  }, [router]);
 
   useEffect(() => {
-    if (!token) {
-      router.push('/login');
-      return;
-    }
-
-    if (!user) {
+    if (isInitialized && token && !user) {
       dispatch(getProfile());
     }
-  }, [token, user, dispatch, router]);
+  }, [isInitialized, token, user, dispatch]);
+
+  // 等待初始化完成
+  if (!isInitialized) {
+    return (
+      <div className="flex min-h-screen items-center justify-center">
+        <Loader2 className="h-8 w-8 animate-spin text-primary" />
+      </div>
+    );
+  }
 
   if (!token) {
     return null;