fix(PingServicesManager): improve error handling during save operation and streamline etag management for UI settings

frontend/src/PingServicesManager.jsx

@@ -65,7 +65,7 @@ export default function PingServicesManager() {
       const res = await api.get('/ui-settings');
       const data = res?.data || {};
       setRawSettings(data);
-      setEtag(String(res?.headers?.etag || res?.headers?.ETag || '').replace(/"/g, ''));
+      setEtag(String(res?.headers?.etag || res?.headers?.ETag || ''));
       const list = Array.isArray(data.pingServicesList) ? data.pingServicesList : [];
       setItems(list.map((s) => ({
         id: String(s?.id ?? '').trim() || slugId(s?.name),
@@ -91,25 +91,42 @@ export default function PingServicesManager() {
     setSaving(true);
     setError('');
     setSuccess('');
+    const payloadToSave = {
+      ...rawSettings,
+      pingServicesList: items.map((s) => ({
+        id: s.id,
+        name: s.name,
+        host: s.host,
+        port: s.port,
+        icon: s.icon,
+        color: s.color,
+      })),
+    };
     try {
-      const payload = {
-        ...rawSettings,
-        pingServicesList: items.map((s) => ({
-          id: s.id,
-          name: s.name,
-          host: s.host,
-          port: s.port,
-          icon: s.icon,
-          color: s.color,
-        })),
-      };
-      const res = await api.post('/ui-settings', { settings: payload, etag });
-      setRawSettings(payload);
-      setEtag(String(res?.data?.etag || etag));
+      let currentEtag = etag;
+      let res = await api.post('/ui-settings', { settings: payloadToSave, etag: currentEtag });
+      setRawSettings(payloadToSave);
+      setEtag(String(res?.data?.etag || currentEtag));
       setSuccess('Список сервисов сохранён');
       setTimeout(() => setSuccess(''), 3000);
     } catch (e) {
-      setError(e?.response?.data?.message || 'Не удалось сохранить');
+      if (e?.response?.status === 412) {
+        try {
+          const fresh = await api.get('/ui-settings');
+          const freshData = fresh?.data || {};
+          const freshEtag = String(fresh?.headers?.etag || fresh?.headers?.ETag || '');
+          const retryPayload = { ...freshData, pingServicesList: payloadToSave.pingServicesList };
+          const retryRes = await api.post('/ui-settings', { settings: retryPayload, etag: freshEtag });
+          setRawSettings(retryPayload);
+          setEtag(String(retryRes?.data?.etag || freshEtag));
+          setSuccess('Список сервисов сохранён (настройки были обновлены)');
+          setTimeout(() => setSuccess(''), 3000);
+        } catch (retryErr) {
+          setError(retryErr?.response?.data?.message || 'Настройки изменились. Обновите страницу и сохраните снова.');
+        }
+      } else {
+        setError(e?.response?.data?.message || 'Не удалось сохранить');
+      }
     } finally {
       setSaving(false);
     }