perf: reduce relay status polling interval to 20 seconds

Change relay status polling from 5s (default) and 2s (Settings/Indicator) to 20s across the board to reduce CPU usage and network requests

src/hooks/useRelayStatus.ts

@@ -9,7 +9,7 @@ interface UseRelayStatusParams {
 
 export function useRelayStatus({ 
   relayPool, 
-  pollingInterval = 5000 
+  pollingInterval = 20000 
 }: UseRelayStatusParams) {
   const [relayStatuses, setRelayStatuses] = useState<RelayStatus[]>([])