feat(ping): add ping caching functionality with configurable duration in UI settings

frontend/src/components/SettingsModal.jsx

@@ -19,6 +19,7 @@ export default function SettingsModal({ open, onClose }) {
   const [wsUrl, setWsUrl] = useState('');
   const [baseAS, setBaseAS] = useState('65001');
   const [pingDomain, setPingDomain] = useState('');
+  const [pingCacheMinutes, setPingCacheMinutes] = useState('');
   const [ptrZoneReplaceFrom, setPtrZoneReplaceFrom] = useState('');
   const [ptrZoneReplaceTo, setPtrZoneReplaceTo] = useState('');
 
@@ -37,6 +38,7 @@ export default function SettingsModal({ open, onClose }) {
         setWsUrl(String(data?.wsUpdateUrl || ''));
         setBaseAS(String(data?.baseAS || '65001'));
         setPingDomain(String(data?.pingDomain || '').trim());
+        setPingCacheMinutes(data?.pingCacheMinutes != null ? String(data.pingCacheMinutes) : '');
         setPtrZoneReplaceFrom(String(data?.ptrZoneReplaceFrom || ''));
         setPtrZoneReplaceTo(String(data?.ptrZoneReplaceTo || ''));
         const e = res?.headers?.etag || res?.headers?.ETag || '';
@@ -100,6 +102,7 @@ export default function SettingsModal({ open, onClose }) {
         wsUpdateUrl: String(wsUrl || '').trim(),
         baseAS: String(baseAS || '65001').trim(),
         pingDomain: String(pingDomain || '').trim(),
+        pingCacheMinutes: Math.max(0, parseInt(pingCacheMinutes, 10) || 0),
         ptrZoneReplaceFrom: String(ptrZoneReplaceFrom || '').trim(),
         ptrZoneReplaceTo: String(ptrZoneReplaceTo || '').trim(),
       };
@@ -212,6 +215,18 @@ export default function SettingsModal({ open, onClose }) {
               disabled={loading || saving}
             />
 
+            <FormField
+              label="Срок кеша пинга (мин)"
+              name="pingCacheMinutes"
+              type="number"
+              value={pingCacheMinutes}
+              onChange={setPingCacheMinutes}
+              placeholder="0"
+              helpText="0 — без кеша. При значении больше 0 результаты пинга кешируются в S3 на указанное количество минут."
+              disabled={loading || saving}
+              min={0}
+            />
+
             <div className="mt-4 pt-3 border-top">
               <h6 className="mb-3">Настройка PTR зоны</h6>
               <div className="row g-3">