refactor(PingServicesManager): replace PageHeaderActions with a custom button list for improved UI structure

frontend/src/PingServicesManager.jsx

@@ -9,7 +9,6 @@ import {
   IconSearch,
 } from '@tabler/icons-react';
 import PageHeader from './components/PageHeader.jsx';
-import PageHeaderActions from './components/PageHeaderActions.jsx';
 import FormModal from './components/FormModal.jsx';
 import FormField from './components/FormField.jsx';
 import ConfirmModal from './components/ConfirmModal.jsx';
@@ -212,7 +211,7 @@ export default function PingServicesManager() {
         title="Пинг сервисов"
         icon={<IconCloud size={24} />}
         actions={(
-          <PageHeaderActions>
+          <div className="btn-list">
             <button
               type="button"
               className="btn btn-primary"
@@ -232,7 +231,7 @@ export default function PingServicesManager() {
               <IconDeviceFloppy size={18} className="me-1" />
               Сохранить
             </button>
-          </PageHeaderActions>
+          </div>
         )}
       />