Fix UTF-8 character display in debug page response bodies

packages/leancode_debug_page/lib/src/core/logging_http_client.dart

@@ -1,4 +1,5 @@
 import 'dart:async';
+import 'dart:convert';
 
 import 'package:http/http.dart' as http;
 import 'package:leancode_debug_page/src/models/log_gatherer.dart';
@@ -59,9 +60,10 @@ class LoggingHttpClient extends http.BaseClient
 
     return http.StreamedResponse(
       response.stream.doOnData(responseBodyBytes.addAll).doOnDone(() {
-        responseBodyCompleter.complete(
-          http.Response.bytes(responseBodyBytes, response.statusCode).body,
-        );
+        // Decode the response body using UTF-8 encoding to properly handle
+        // special characters like Polish letters (Ł, Ń, ą, etc.)
+        final responseBody = utf8.decode(responseBodyBytes, allowMalformed: true);
+        responseBodyCompleter.complete(responseBody);
       }),
       response.statusCode,
       contentLength: response.contentLength,

packages/leancode_debug_page/test/logging_http_client_test.dart

@@ -3,6 +3,8 @@
 // clearly show all parameters being tested.
 // ignore_for_file: avoid_redundant_argument_values
 
+import 'dart:convert';
+
 import 'package:flutter_test/flutter_test.dart';
 import 'package:http/http.dart';
 import 'package:leancode_debug_page/src/core/logging_http_client.dart';
@@ -96,6 +98,43 @@ void main() {
           );
         },
       );
+
+      test(
+        'properly decodes UTF-8 characters including Polish letters',
+        () async {
+          const polishText = 'Autoryzacja nie została wykonana. Łódź, Gdańsk, Kraków.';
+          final polishBytes = utf8.encode(polishText);
+          final streamWithPolishText = Stream.fromIterable([polishBytes]);
+
+          when<Future<StreamedResponse>>(() => mockHttpClient.send(any()))
+              .thenAnswer(
+            (invocation) async => StreamedResponse(
+              streamWithPolishText,
+              statusCode,
+              contentLength: polishBytes.length,
+              request: request,
+              headers: headers,
+              isRedirect: isRedirect,
+              persistentConnection: persistentConnection,
+              reasonPhrase: reasonPhrase,
+            ),
+          );
+
+          await loggingHttpClient.send(request);
+
+          // Wait for the response body to be completed
+          await Future.delayed(const Duration(milliseconds: 100));
+
+          expect(loggingHttpClient.logs, hasLength(1));
+          final log = loggingHttpClient.logs.first;
+          final responseBody = await log.responseBodyCompleter.future;
+
+          expect(responseBody, contains('Autoryzacja'));
+          expect(responseBody, contains('Łódź'));
+          expect(responseBody, contains('Gdańsk'));
+          expect(responseBody, contains('Kraków'));
+        },
+      );
     },
   );
 }