fix(layout): 顶栏用户区去掉盾牌图标与管理员徽章,只留用户名

frontend/src/components/Layout.tsx

@@ -10,7 +10,6 @@ import {
   LogOut,
   PanelLeftClose,
   PanelLeftOpen,
-  Shield,
   ChevronRight,
   Activity,
   Menu,
@@ -240,13 +239,7 @@ const Layout = memo(function Layout({ children }: { children: React.ReactNode })
             <ThemeToggle />
             {user && (
               <div className="flex items-center gap-3 text-sm text-muted-foreground">
-                <div className="flex items-center gap-2">
-                  <Shield className="w-4 h-4" />
-                  <span>{user.username}</span>
-                  <span className="px-2 py-0.5 rounded-full bg-success/10 text-success text-xs font-medium">
-                    {user.role === 'admin' ? t('layout.admin') : user.role}
-                  </span>
-                </div>
+                <span>{user.username}</span>
                 <button
                   onClick={handleLogout}
                   title={t('layout.logout')}