feat(status): implement status page for app startup

- Add StatusPage widget to display status during critical startup sequence
- Handle config fetching and error states
- Implement retry functionality for failed config fetch
- Update view exports to include new StatusPage

Author: fulleni

lib/status/view/status_page.dart

@@ -0,0 +1,53 @@
+import 'package:core/core.dart' hide AppStatus;
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:flutter_news_app_mobile_client_full_source_code/app/bloc/app_bloc.dart';
+import 'package:flutter_news_app_mobile_client_full_source_code/l10n/l10n.dart';
+import 'package:ui_kit/ui_kit.dart';
+
+/// A page that serves as the root UI during the critical startup sequence.
+///
+/// This widget is displayed *before* the main application's router and UI
+/// shell are built. It is responsible for showing the user a clear status
+/// while the remote configuration is being fetched, and it provides a way
+/// for the user to retry if the fetch operation fails.
+class StatusPage extends StatelessWidget {
+  /// {@macro status_page}
+  const StatusPage({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    // This page is a temporary root widget shown during the critical
+    // startup phase before the main app UI (and GoRouter) is built.
+    // It handles two key states: fetching the remote configuration and
+    // recovering from a failed fetch.
+    return Scaffold(
+      body: BlocBuilder<AppBloc, AppState>(
+        builder: (context, state) {
+          final l10n = AppLocalizationsX(context).l10n;
+
+          if (state.status == AppStatus.configFetching) {
+            // While fetching configuration, display a clear loading indicator.
+            // This uses a shared widget from the UI kit for consistency.
+            return LoadingStateWidget(
+              icon: Icons.settings_applications_outlined,
+              headline: l10n.headlinesFeedLoadingHeadline,
+              subheadline: l10n.pleaseWait,
+            );
+          }
+
+          // If fetching fails, show an error message with a retry option.
+          // This allows the user to recover from transient network issues.
+          return FailureStateWidget(
+            exception: const NetworkException(), // A generic network error
+            retryButtonText: 'l10n.retryButtonText', //TODO(fulleni): localize me.
+            onRetry: () {
+              // Dispatch the event to AppBloc to re-trigger the fetch.
+              context.read<AppBloc>().add(const AppConfigFetchRequested());
+            },
+          );
+        },
+      ),
+    );
+  }
+}

lib/status/view/view.dart

@@ -1,2 +1,3 @@
 export 'maintenance_page.dart';
+export 'status_page.dart';
 export 'update_required_page.dart';