fix: use async api to checkNodeHealth (#2421)

cw_monero/lib/api/wallet.dart

@@ -175,7 +175,10 @@ int getNodeHeightSync() {
   return cachedNodeHeight;
 }
 
-bool isConnectedSync() => currentWallet?.connected() != 0;
+Future<bool> isConnected() async {
+  final wptrAddress = currentWallet!.ffiAddress();
+  return await Isolate.run(() => monero.Wallet_connected(Pointer.fromAddress(wptrAddress))) == 1;
+}
 
 Future<bool> setupNodeSync(
     {required String address,
@@ -396,8 +399,6 @@ void startRefresh() => startRefreshSync();
 
 Future<void> store() async => _storeSync(0);
 
-Future<bool> isConnected() async => isConnectedSync();
-
 Future<int> getNodeHeight() async => getNodeHeightSync();
 
 void rescanBlockchainAsync() => currentWallet!.rescanBlockchainAsync();

cw_monero/lib/monero_wallet.dart

@@ -188,7 +188,7 @@ abstract class MoneroWalletBase extends WalletBase<MoneroBalance,
   Future<bool> checkNodeHealth() async {
     try {
       // Check if the wallet is currently connected to the daemon
-      final isConnected = monero_wallet.isConnectedSync();
+      final isConnected = await monero_wallet.isConnected();
       
       if (!isConnected) {
         return false; // It's not connected to daemon