Revert "temporary workaround for 500 error"

This reverts commit 8436cd402632ca7be9272a1c72fdaf0763dcefb6.

mobile/lib/infrastructure/repositories/user_api.repository.dart

@@ -1,4 +1,3 @@
-import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:http/http.dart';
@@ -19,34 +18,8 @@ class UserApiRepository extends ApiRepository {
   }
 
   Future<String> createProfileImage({required String name, required Uint8List data}) async {
-    // Workaround: the autogenerated OpenAPI client forces `Content-Type: multipart/form-data`
+    final res = await checkNull(_api.createProfileImage(MultipartFile.fromBytes('file', data, filename: name)));
-    // without a boundary, which can break multer parsing server-side.
+    return res.profileImagePath;
-    // We bypass `UsersApi.createProfileImage()` and send the multipart request directly,
-    // while still reusing the configured basePath + auth headers + http client.
-    final apiClient = _api.apiClient;
-
-    final headers = <String, String>{};
-    await apiClient.authentication?.applyToParams(<QueryParam>[], headers);
-    headers.addAll(apiClient.defaultHeaderMap);
-    headers.remove('Content-Type');
-    headers.remove('content-type');
-
-    final filename = name.isNotEmpty ? name : 'profile-picture.png';
-    final uri = Uri.parse('${apiClient.basePath}/users/profile-image');
-
-    final request = MultipartRequest('POST', uri)
-      ..headers.addAll(headers)
-      ..files.add(MultipartFile.fromBytes('file', data, filename: filename));
-
-    final streamed = await apiClient.client.send(request);
-    final response = await Response.fromStream(streamed);
-
-    if (response.statusCode >= 400) {
-      throw ApiException(response.statusCode, response.body);
-    }
-
-    final body = jsonDecode(response.body) as Map<String, dynamic>;
-    return body['profileImagePath'] as String;
   }
 
   Future<List<UserDto>> getAll() async {