migrated the breaker system to MarianumConnect and refactored the API response to a rule-based model with support for version-specific blocks using maxBuild.

lib/api/marianumconnect/queries/get_breakers/get_breakers.dart

@@ -0,0 +1,26 @@
+import 'package:dio/dio.dart';
+
+import '../../errors/marianumconnect_error.dart';
+import '../../marianumconnect_api.dart';
+import '../../marianumconnect_endpoint.dart';
+import 'get_breakers_response.dart';
+
+/// Fetches the app maintenance breaker rules from `GET /api/mobile/v1/breaker`.
+/// The endpoint is public: the bearer token is attached if present but not
+/// required, so this also works before login (e.g. to block the whole app).
+class GetBreakers {
+  final Dio _dio;
+
+  GetBreakers({Dio? dio}) : _dio = dio ?? MarianumConnectApi.dio();
+
+  Future<GetBreakersResponse> run() async {
+    try {
+      final response = await _dio.get<Map<String, dynamic>>(
+        MarianumConnectEndpoint.resolve('breaker'),
+      );
+      return GetBreakersResponse.fromJson(response.data!);
+    } on DioException catch (e) {
+      throw mapMarianumConnectError(e);
+    }
+  }
+}