feat: detect admin/dispute DMs in background notification pipeline

lib/features/disputes/notifiers/dispute_chat_notifier.dart

@@ -14,6 +14,7 @@ import 'package:mostro_mobile/features/order/providers/order_notifier_provider.d
 import 'package:mostro_mobile/shared/providers/mostro_service_provider.dart';
 import 'package:mostro_mobile/shared/providers/nostr_service_provider.dart';
 import 'package:mostro_mobile/shared/providers/session_notifier_provider.dart';
+import 'package:mostro_mobile/shared/utils/nostr_utils.dart';
 import 'package:sembast/sembast.dart';
 
 /// State for dispute chat messages
@@ -157,7 +158,7 @@ class DisputeChatNotifier extends StateNotifier<DisputeChatState> {
           final messageData = contentData[0];
 
           // Check if it's the CLI format with Message enum (has "dm" key)
-          if (messageData is Map && messageData.containsKey('dm')) {
+          if (NostrUtils.isDmPayload(messageData)) {
             final dmData = messageData['dm'];
             if (dmData is Map && dmData.containsKey('payload')) {
               final payload = dmData['payload'];

lib/features/notifications/services/background_notification_service.dart

@@ -18,6 +18,7 @@ import 'package:mostro_mobile/features/key_manager/key_derivator.dart';
 import 'package:mostro_mobile/features/key_manager/key_manager.dart';
 import 'package:mostro_mobile/features/key_manager/key_storage.dart';
 import 'package:mostro_mobile/features/notifications/utils/notification_data_extractor.dart';
+import 'package:mostro_mobile/shared/utils/nostr_utils.dart';
 import 'package:mostro_mobile/features/notifications/utils/notification_message_mapper.dart';
 import 'package:mostro_mobile/generated/l10n.dart';
 import 'package:mostro_mobile/generated/l10n_en.dart';
@@ -171,6 +172,16 @@ Future<MostroMessage?> _decryptAndProcessEvent(NostrEvent event) async {
       return null;
     }
 
+    // Detect admin/dispute DM format: [{"dm": {"action": "send-dm", ...}}]
+    final firstItem = result[0];
+    if (NostrUtils.isDmPayload(firstItem)) {
+      return MostroMessage(
+        action: mostro_action.Action.sendDm,
+        id: matchingSession.orderId,
+        timestamp: event.createdAt?.millisecondsSinceEpoch,
+      );
+    }
+
     final mostroMessage = MostroMessage.fromJson(result[0]);
     mostroMessage.timestamp = event.createdAt?.millisecondsSinceEpoch;
 

lib/features/notifications/utils/notification_data_extractor.dart

@@ -177,20 +177,28 @@ class NotificationDataExtractor {
         // No additional values needed
         break;
 
+      case Action.sendDm:
+        // Admin/dispute DM — no payload extraction needed, generic message
+        break;
+
+      case Action.cooperativeCancelAccepted:
+        // No additional values needed
+        break;
+
       case Action.cantDo:
         final cantDo = event.getPayload<CantDo>();
         values['reason'] = cantDo?.cantDoReason.toString();
         isTemporary = true; // cantDo notifications are temporary
         break;
-        
+
       case Action.rate:
         // No additional values needed
         break;
-        
+
       case Action.rateReceived:
         // This action doesn't generate notifications
         return null;
-        
+
       default:
         // Unknown actions generate temporary notifications
         isTemporary = true;

lib/services/mostro_service.dart

@@ -13,6 +13,7 @@ import 'package:mostro_mobile/shared/providers.dart';
 import 'package:mostro_mobile/features/settings/settings_provider.dart';
 import 'package:mostro_mobile/features/order/providers/order_notifier_provider.dart';
 import 'package:mostro_mobile/features/key_manager/key_manager_provider.dart';
+import 'package:mostro_mobile/shared/utils/nostr_utils.dart';
 
 class MostroService {
   final Ref ref;
@@ -130,7 +131,7 @@ class MostroService {
       }
 
       // Skip dispute chat messages (they have "dm" key and are handled by DisputeChatNotifier)
-      if (result[0] is Map && (result[0] as Map).containsKey('dm')) {
+      if (NostrUtils.isDmPayload(result[0])) {
         logger.i('Skipping dispute chat message (handled by DisputeChatNotifier)');
         return;
       }

lib/shared/utils/nostr_utils.dart

@@ -379,6 +379,12 @@ class NostrUtils {
     }
   }
 
+  /// Checks if a decoded Mostro payload item is a DM (dispute/admin chat) message.
+  /// DM messages use the format: {"dm": {"action": "send-dm", ...}}
+  static bool isDmPayload(dynamic item) {
+    return item is Map && item.containsKey('dm');
+  }
+
   static Future<String> encryptNIP44(
       String content, String privkey, String pubkey) async {
     try {

test/features/notifications/services/background_notification_dm_detection_test.dart

@@ -0,0 +1,134 @@
+import 'dart:convert';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mostro_mobile/data/models/enums/action.dart';
+import 'package:mostro_mobile/data/models/mostro_message.dart';
+import 'package:mostro_mobile/features/notifications/utils/notification_data_extractor.dart';
+import 'package:mostro_mobile/shared/utils/nostr_utils.dart';
+
+/// Tests for the admin/dispute DM background notification pipeline (Phase 1).
+///
+/// Validates three layers:
+/// 1. [NostrUtils.isDmPayload] — pure detection of the `{"dm": ...}` envelope
+/// 2. [MostroMessage] construction — synthetic message with [Action.sendDm]
+/// 3. [NotificationDataExtractor] — ensures sendDm is NOT marked temporary
+void main() {
+  group('NostrUtils.isDmPayload', () {
+    test('detects dm wrapper key in decoded JSON', () {
+      final dmPayload = jsonDecode(
+        '[{"dm": {"action": "send-dm", "payload": {"text_message": "Hello"}}}]',
+      );
+
+      expect(dmPayload, isList);
+      expect(dmPayload, isNotEmpty);
+      expect(NostrUtils.isDmPayload(dmPayload[0]), isTrue);
+    });
+
+    test('does not detect dm key in standard Mostro message', () {
+      final orderPayload = jsonDecode(
+        '[{"order": {"action": "new-order", "id": "abc123", "payload": null}}]',
+      );
+
+      expect(NostrUtils.isDmPayload(orderPayload[0]), isFalse);
+    });
+
+    test('does not detect dm key in restore message', () {
+      final restorePayload = jsonDecode(
+        '[{"restore": {"action": "restore-session", "id": "abc123"}}]',
+      );
+
+      expect(NostrUtils.isDmPayload(restorePayload[0]), isFalse);
+    });
+
+    test('does not detect dm key in cant-do message', () {
+      final cantDoPayload = jsonDecode(
+        '[{"cant-do": {"action": "cant-do", "payload": null}}]',
+      );
+
+      expect(NostrUtils.isDmPayload(cantDoPayload[0]), isFalse);
+    });
+
+    test('handles dm payload with minimal content', () {
+      final dmPayload = jsonDecode('[{"dm": {}}]');
+
+      expect(NostrUtils.isDmPayload(dmPayload[0]), isTrue);
+    });
+
+    test('returns false for non-Map types', () {
+      expect(NostrUtils.isDmPayload('string'), isFalse);
+      expect(NostrUtils.isDmPayload(42), isFalse);
+      expect(NostrUtils.isDmPayload(null), isFalse);
+      expect(NostrUtils.isDmPayload([]), isFalse);
+    });
+  });
+
+  group('MostroMessage construction for DM', () {
+    test('preserves orderId and timestamp with sendDm action', () {
+      const testOrderId = 'test-order-123';
+      const testTimestamp = 1700000000000;
+
+      final message = MostroMessage(
+        action: Action.sendDm,
+        id: testOrderId,
+        timestamp: testTimestamp,
+      );
+
+      expect(message.action, Action.sendDm);
+      expect(message.id, testOrderId);
+      expect(message.timestamp, testTimestamp);
+    });
+  });
+
+  group('NotificationDataExtractor for sendDm', () {
+    test('produces non-temporary notification data', () async {
+      final message = MostroMessage(
+        action: Action.sendDm,
+        id: 'order-abc',
+        timestamp: 1700000000000,
+      );
+
+      final data = await NotificationDataExtractor.extractFromMostroMessage(
+        message,
+        null,
+      );
+
+      expect(data, isNotNull);
+      expect(data!.isTemporary, isFalse);
+      expect(data.action, Action.sendDm);
+      expect(data.orderId, 'order-abc');
+    });
+
+    test('returns empty values map (no payload extraction)', () async {
+      final message = MostroMessage(
+        action: Action.sendDm,
+        id: 'order-xyz',
+      );
+
+      final data = await NotificationDataExtractor.extractFromMostroMessage(
+        message,
+        null,
+      );
+
+      expect(data, isNotNull);
+      expect(data!.values, isEmpty);
+    });
+  });
+
+  group('NotificationDataExtractor for cooperativeCancelAccepted', () {
+    test('produces non-temporary notification data', () async {
+      final message = MostroMessage(
+        action: Action.cooperativeCancelAccepted,
+        id: 'order-cancel',
+      );
+
+      final data = await NotificationDataExtractor.extractFromMostroMessage(
+        message,
+        null,
+      );
+
+      expect(data, isNotNull);
+      expect(data!.isTemporary, isFalse);
+      expect(data.action, Action.cooperativeCancelAccepted);
+    });
+  });
+}