feat(frontend): make baseUrl dynamic for external network access and clear default login inputs

FinlyticApp/lib/features/dashboard/widgets/daily_news_snapshot.dart

@@ -14,19 +14,19 @@ import '../../news/widgets/article_sentiment_dialog.dart';
 
 class DailyNewsSnapshot extends StatelessWidget {
   final ApiClient apiClient;
-  final String backendUrl;
+  final String? backendUrl;
 
   const DailyNewsSnapshot({
     super.key,
     required this.apiClient,
-    this.backendUrl = 'http://localhost:5000',
+    this.backendUrl,
   });
 
   @override
   Widget build(BuildContext context) {
     return BlocProvider(
       create: (context) => NewsBloc(
-        repository: NewsRepository(apiClient: apiClient, backendUrl: backendUrl),
+        repository: NewsRepository(apiClient: apiClient, backendUrl: backendUrl ?? ApiClient.baseUrl),
       )..add(FetchNews(date: DateTime.now().toIso8601String().substring(0, 10))),
       child: const _DailyNewsSnapshotContent(),
     );