Add functionality to manage account members: implement add and remove member events, update account repository methods, and integrate with trip details for participant management.

lib/repositories/account_repository.dart

@@ -198,4 +198,22 @@ class AccountRepository {
           return null;
         });
   }
+
+  Future<void> addMemberToAccount(String accountId, GroupMember member) async {
+    try {
+      await _membersCollection(accountId).doc(member.userId).set(member.toMap());
+    } catch (e) {
+      _errorService.logError('account_repository.dart', 'Erreur lors de l\'ajout du membre: $e');
+      throw Exception('Erreur lors de l\'ajout du membre: $e');
+    }
+  }
+
+  Future<void> removeMemberFromAccount(String accountId, String memberId) async {
+    try {
+      await _membersCollection(accountId).doc(memberId).delete();
+    } catch (e) {
+      _errorService.logError('account_repository.dart', 'Erreur lors de la suppression du membre: $e');
+      throw Exception('Erreur lors de la suppression du membre: $e');
+    }
+  }
 }