migrated Marianum Message module to the Marianum-Connect API and implemented push notification deep linking

lib/state/app/modules/marianum_message/data_provider/marianum_message_get_messages.dart

@@ -1,13 +1,53 @@
 import 'package:dio/dio.dart';
+import 'package:intl/intl.dart';
 
-import '../../../basis/dataloader/mhsl_data_loader.dart';
-import '../../../infrastructure/data_loader/data_loader.dart';
+import '../../../../../api/marianumconnect/errors/marianumconnect_error.dart';
+import '../../../../../api/marianumconnect/marianumconnect_api.dart';
+import '../../../../../api/marianumconnect/marianumconnect_endpoint.dart';
 import '../bloc/marianum_message_state.dart';
 
-class MarianumMessageGetMessages extends MhslDataLoader<MarianumMessageList> {
-  @override
-  Future<Response<String>> fetch() async => dio.get('/message/messages.json');
-  @override
-  MarianumMessageList assemble(DataLoaderResult data) =>
-      MarianumMessageList.fromJson(data.asMap());
+/// Loads the "Marianum Message" list from `GET /api/mobile/v1/newsletter`
+/// (formerly the mhsl.eu `message/messages.json` endpoint). Bearer token is
+/// attached by the shared Marianum-Connect dio.
+class MarianumMessageGetMessages {
+  final Dio _dio;
+
+  MarianumMessageGetMessages({Dio? dio}) : _dio = dio ?? MarianumConnectApi.dio();
+
+  Future<MarianumMessageList> run() async {
+    try {
+      final response = await _dio.get<List<dynamic>>(
+        MarianumConnectEndpoint.resolve('newsletter'),
+      );
+      final messages = (response.data ?? const [])
+          .cast<Map<String, dynamic>>()
+          .map(_mapItem)
+          .toList();
+      return MarianumMessageList(
+        base: MarianumConnectEndpoint.current(),
+        messages: messages,
+      );
+    } on DioException catch (e) {
+      throw mapMarianumConnectError(e);
+    }
+  }
+
+  MarianumMessage _mapItem(Map<String, dynamic> map) => MarianumMessage(
+    id: map['id'] as String,
+    name: map['title'] as String? ?? '',
+    date: _formatDate(map['date'] as String?),
+    description: map['description'] as String? ?? '',
+    url: map['fileUrl'] as String? ?? '',
+  );
+
+  static final DateFormat _monthYear = DateFormat.yMMMM('de');
+
+  /// Server sends ISO `yyyy-MM-dd`; the list shows only the German month + year
+  /// (e.g. "April 2024").
+  static String _formatDate(String? iso) {
+    if (iso == null || iso.isEmpty) return '';
+    final parsed = DateTime.tryParse(iso);
+    if (parsed == null) return iso;
+    return _monthYear.format(parsed);
+  }
 }