feat(NetworkMapDashboard): implement cache handling for ping and speed requests to optimize data fetching

frontend/src/NetworkMapDashboard.jsx

@@ -78,11 +78,14 @@ export default function NetworkMapDashboard() {
   const [error, setError] = useState(null);
   const pingAbortRef = useRef(false);
   const speedAbortRef = useRef(false);
+  /** Время применения кеша от планировщика (чтобы не запускать пинг/скорость повторно при открытии) */
+  const cacheAppliedAtRef = useRef(null);
 
   /** Связи строятся из интерфейсов раздела «Сетевые настройки» (/network-config), tunnelInterfaces */
   const fetchData = useCallback(async () => {
     setLoading(true);
     setError(null);
+    cacheAppliedAtRef.current = null;
     try {
       const [serversRes, configRes, uiSettingsRes, cacheRes] = await Promise.all([
         api.get('/servers'),
@@ -142,6 +145,7 @@ export default function NetworkMapDashboard() {
         Object.keys(cache.pingMap || {}).forEach((k) => {
           pingTimestampsRef.current[k] = cache.updatedAt;
         });
+        cacheAppliedAtRef.current = cache.updatedAt;
       } else {
         setSpeedMap({});
       }
@@ -276,21 +280,29 @@ export default function NetworkMapDashboard() {
 
   useEffect(() => {
     if (!loading && servers.length > 0 && connections.length > 0) {
+      const cacheMaxAgeMs = Math.max((pingCacheSeconds || 60) * 1000, 60 * 1000);
+      if (cacheAppliedAtRef.current && Date.now() - cacheAppliedAtRef.current < cacheMaxAgeMs) {
+        return;
+      }
       requestPings();
     }
     return () => {
       pingAbortRef.current = true;
     };
-  }, [loading, connections.length]);
+  }, [loading, connections.length, pingCacheSeconds, requestPings]);
 
   useEffect(() => {
     if (!loading && connections.length > 0) {
+      const cacheMaxAgeMs = Math.max((pingCacheSeconds || 60) * 1000, 60 * 1000);
+      if (cacheAppliedAtRef.current && Date.now() - cacheAppliedAtRef.current < cacheMaxAgeMs) {
+        return;
+      }
       requestSpeeds();
     }
     return () => {
       speedAbortRef.current = true;
     };
-  }, [loading, connections.length, requestSpeeds]);
+  }, [loading, connections.length, pingCacheSeconds, requestSpeeds]);
 
   const handleRefreshPings = () => {
     requestPings();