revert toggle on zhtlc activation config cancel

lib/bloc/coins_bloc/coins_repo.dart

@@ -32,6 +32,14 @@ import 'package:web_dex/services/arrr_activation/arrr_activation_service.dart';
 import 'package:web_dex/services/fd_monitor_service.dart';
 import 'package:web_dex/shared/utils/platform_tuner.dart';
 
+/// Exception used to indicate that ZHTLC activation was cancelled by the user.
+class ZhtlcActivationCancelled implements Exception {
+  ZhtlcActivationCancelled(this.coinId);
+  final String coinId;
+  @override
+  String toString() => 'ZhtlcActivationCancelled: $coinId';
+}
+
 class CoinsRepo {
   CoinsRepo({
     required KomodoDefiSdk kdfSdk,
@@ -933,13 +941,16 @@ class CoinsRepo {
           // User cancellations have the message "Configuration cancelled by user or timed out"
           final isUserCancellation = message.contains('cancelled by user');
 
-          if (notifyListeners && !isUserCancellation) {
-            _broadcastAsset(coin.copyWith(state: CoinState.suspended));
+          if (isUserCancellation) {
+            // Bubble up a typed cancellation so the UI can revert the toggle
+            throw ZhtlcActivationCancelled(asset.id.id);
           }
 
-          if (!isUserCancellation) {
-            throw Exception("zcoin activaiton failed: $message");
+          if (notifyListeners) {
+            _broadcastAsset(coin.copyWith(state: CoinState.suspended));
           }
+
+          throw Exception('zcoin activaiton failed: $message');
         },
         needsConfiguration: (coinId, requiredSettings) {
           _log.severe(

lib/bloc/coins_manager/coins_manager_bloc.dart

@@ -241,7 +241,17 @@ class CoinsManagerBloc extends Bloc<CoinsManagerEvent, CoinsManagerState> {
         (state.action == CoinsManagerAction.remove && wasSelected);
 
     if (shouldActivate) {
-      await _tryActivateCoin(coin);
+      try {
+        await _tryActivateCoin(coin);
+      } on ZhtlcActivationCancelled {
+        // Revert optimistic selection and show a friendly message
+        selectedCoins.remove(coin);
+        emit(state.copyWith(
+          selectedCoins: selectedCoins.toList(),
+          errorMessage: 'Activation canceled.',
+        ));
+        return;
+      }
     } else {
       await _tryDeactivateCoin(coin);
     }
@@ -265,8 +275,12 @@ class CoinsManagerBloc extends Bloc<CoinsManagerEvent, CoinsManagerState> {
   Future<void> _tryActivateCoin(Coin coin) async {
     try {
       await _coinsRepo.activateCoinsSync([coin]);
+    } on ZhtlcActivationCancelled {
+      // Rethrow so the caller can revert the optimistic toggle and show UI
+      rethrow;
     } catch (e, s) {
       _log.warning('Failed to activate coin ${coin.abbr}', e, s);
+      return;
     }
     _analyticsBloc.logEvent(
       AssetEnabledEventData(