feat: Added Antenna selection to Flex FlexPanel

feat: New settings flexradio to select antennas per band

frontend/src/App.tsx

@@ -13,7 +13,7 @@ import {
   GetStartupStatus, CheckForUpdate,
   WorkedBefore,
   SetCompactMode,
-  GetCATState, SetCATFrequency, SetCATMode, SwitchCATRig,
+  GetCATState, SetCATFrequency, SetCATMode, SwitchCATRig, FlexApplyBandAntenna,
   GetSecretStatus, UnlockSecrets,
   RefreshCtyDat, DownloadAllReferenceLists,
   RotatorGoTo, RotatorStop, GetRotatorHeading,
@@ -1431,6 +1431,19 @@ export default function App() {
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, []);
 
+  // FlexRadio: apply the per-band RX/TX antennas whenever the band changes (rig
+  // QSY, spot click, manual band) — so the right antennas follow the frequency.
+  // Skipped while the band is LOCKED (entering an old QSO off-air) and for non-Flex
+  // backends. The backend no-ops if the band has no configured mapping.
+  const lastAntBandRef = useRef('');
+  useEffect(() => {
+    if (catState.backend !== 'flex' || locks.band) return;
+    const b = band.trim();
+    if (!b || b === lastAntBandRef.current) return;
+    lastAntBandRef.current = b;
+    FlexApplyBandAntenna(b).catch(() => {});
+  }, [band, catState.backend, locks.band]);
+
   // Cluster live wiring: hydrate per-server status + saved server list,
   // then subscribe to push events.
   async function reloadClusterMeta() {