Fix background notifications failing in release builds (#378)

* Add FVM configuration for Flutter version management

* Update background notification icon

* Update local notification icon to use dedicated drawable

Changes the local notification icon from `ic_bg_service_small` to `ic_notification` and adds metadata to preserve the dedicated notification icon in AndroidManifest.xml

* Update notification data extractor to handle fiatSent action

* Format code with consistent early return style

Author: AndreaDiazCorreia

android/app/src/main/AndroidManifest.xml

@@ -52,6 +52,10 @@
 		<meta-data
 			android:name="com.google.firebase.messaging.default_notification_icon"
 			android:resource="@drawable/ic_bg_service_small" />
+		<!-- Preserve ic_notification for local notifications -->
+		<meta-data
+			android:name="com.app.notification_icon"
+			android:resource="@drawable/ic_notification" />
 
 	</application>
 

lib/background/background.dart

@@ -69,7 +69,9 @@ Future<void> serviceMain(ServiceInstance service) async {
 
     subscription.listen((event) async {
       try {
-        if (await eventStore.hasItem(event.id!)) return;
+        if (await eventStore.hasItem(event.id!)) {
+          return;
+        }
         await notification_service.retryNotification(event);
       } catch (e) {
         Logger().e('Error processing event', error: e);

lib/features/notifications/services/background_notification_service.dart

@@ -53,16 +53,18 @@ Future<void> showLocalNotification(NostrEvent event) async {
   try {
     final mostroMessage = await _decryptAndProcessEvent(event);
     if (mostroMessage == null) return;
-    
 
     final sessions = await _loadSessionsFromDatabase();
     final matchingSession = sessions.cast<Session?>().firstWhere(
       (session) => session?.orderId == mostroMessage.id,
       orElse: () => null,
     );
-    
+
     final notificationData = await NotificationDataExtractor.extractFromMostroMessage(mostroMessage, null, session: matchingSession);
-    if (notificationData == null || notificationData.isTemporary) return;
+
+    if (notificationData == null || notificationData.isTemporary) {
+      return;
+    }
 
     final notificationText = await _getLocalizedNotificationText(notificationData.action, notificationData.values);
     final expandedText = _getExpandedText(notificationData.values);
@@ -79,7 +81,7 @@ Future<void> showLocalNotification(NostrEvent event) async {
         enableVibration: true,
         ticker: notificationText.title,
         icon: '@drawable/ic_notification',
-        styleInformation: expandedText != null 
+        styleInformation: expandedText != null
             ? BigTextStyleInformation(expandedText, contentTitle: notificationText.title)
             : null,
         category: AndroidNotificationCategory.message,
@@ -111,25 +113,34 @@ Future<void> showLocalNotification(NostrEvent event) async {
 
 Future<MostroMessage?> _decryptAndProcessEvent(NostrEvent event) async {
   try {
-    if (event.kind != 4 && event.kind != 1059) return null;
+    if (event.kind != 4 && event.kind != 1059) {
+      return null;
+    }
 
     final sessions = await _loadSessionsFromDatabase();
+
     final matchingSession = sessions.cast<Session?>().firstWhere(
       (s) => s?.tradeKey.public == event.recipient,
       orElse: () => null,
     );
 
-    if (matchingSession == null) return null;
+    if (matchingSession == null) {
+      return null;
+    }
 
     final decryptedEvent = await event.unWrap(matchingSession.tradeKey.private);
-    if (decryptedEvent.content == null) return null;
+    if (decryptedEvent.content == null) {
+      return null;
+    }
 
     final result = jsonDecode(decryptedEvent.content!);
-    if (result is! List || result.isEmpty) return null;
+    if (result is! List || result.isEmpty) {
+      return null;
+    }
 
     final mostroMessage = MostroMessage.fromJson(result[0]);
     mostroMessage.timestamp = event.createdAt?.millisecondsSinceEpoch;
-    
+
     return mostroMessage;
   } catch (e) {
     Logger().e('Decrypt error: $e');
@@ -258,25 +269,25 @@ String? _getExpandedText(Map<String, dynamic> values) {
 }
 
 
-Future<void> retryNotification(NostrEvent event, {int maxAttempts = 3}) async {  
-  int attempt = 0;  
-  bool success = false;  
-  
-  while (!success && attempt < maxAttempts) {  
-    try {  
-      await showLocalNotification(event);  
-      success = true;  
-    } catch (e) {  
-      attempt++;  
-      if (attempt >= maxAttempts) {  
-        Logger().e('Failed to show notification after $maxAttempts attempts: $e');  
-        break;  
-      }  
-      
-      // Exponential backoff: 1s, 2s, 4s, etc.  
-      final backoffSeconds = pow(2, attempt - 1).toInt();  
-      Logger().e('Notification attempt $attempt failed: $e. Retrying in ${backoffSeconds}s');  
-      await Future.delayed(Duration(seconds: backoffSeconds));  
-    }  
-  }  
+Future<void> retryNotification(NostrEvent event, {int maxAttempts = 3}) async {
+  int attempt = 0;
+  bool success = false;
+
+  while (!success && attempt < maxAttempts) {
+    try {
+      await showLocalNotification(event);
+      success = true;
+    } catch (e) {
+      attempt++;
+      if (attempt >= maxAttempts) {
+        Logger().e('Failed to show notification after $maxAttempts attempts: $e');
+        break;
+      }
+
+      // Exponential backoff: 1s, 2s, 4s, etc.
+      final backoffSeconds = pow(2, attempt - 1).toInt();
+      Logger().e('Notification attempt $attempt failed: $e. Retrying in ${backoffSeconds}s');
+      await Future.delayed(Duration(seconds: backoffSeconds));
+    }
+  }
 }  

lib/features/notifications/utils/notification_data_extractor.dart

@@ -108,10 +108,22 @@ class NotificationDataExtractor {
         }
         break;
 
+      case Action.fiatSent:
+        // Notification for seller when buyer marks fiat as sent
+        // This requires seller to release the funds
+        final order = event.getPayload<Order>();
+        if (order != null) {
+          values = {
+            'fiat_code': order.fiatCode,
+            'fiat_amount': order.fiatAmount,
+          };
+        }
+        break;
+
       case Action.fiatSentOk:
         // Only sellers should receive fiat confirmed notifications
         if (session?.role != Role.seller) return null;
-        
+
         final peer = event.getPayload<Peer>();
         if (peer?.publicKey != null) {
           final buyerNym = ref != null