fix:禁工作台跳系统管理

frontend/app/components/admin/DashboardPage.tsx

@@ -14,6 +14,8 @@ export function DashboardPage({
   onNavigate: (page: "scripts" | "schedules" | "system") => void;
 }) {
   const { user, currentWorkspace } = useAuth();
+  const isSystemAdmin = user?.is_system_admin ?? false;
+
   return (
     <section className="dashboard-page">
       <div className="dashboard-hero">
@@ -36,7 +38,9 @@ export function DashboardPage({
       <div className="dashboard-actions">
         <button type="button" onClick={() => onNavigate("scripts")}><Icon name="script" />构建脚本</button>
         <button type="button" onClick={() => onNavigate("schedules")}><Icon name="schedule" />调度配置</button>
-        <button type="button" onClick={() => onNavigate("system")}><Icon name="settings" />系统管理</button>
+        {isSystemAdmin && (
+          <button type="button" onClick={() => onNavigate("system")}><Icon name="settings" />系统管理</button>
+        )}
       </div>
       <div className="dashboard-grid">
         <section className="dashboard-panel dashboard-panel--trend">