feat: implement API client with JSON handling and error mapping; enhance routing and state management in app shell

flutter/lib/features/recipes/presentation/recipes_screen.dart

@@ -1,40 +1,31 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
-import 'package:go_router/go_router.dart';
-import '../../auth/data/auth_providers.dart';
+
+import '../../../core/api/api_error_mapper.dart';
+import '../../../core/ui/async_state_views.dart';
 import '../data/recipe_providers.dart';
 
 class RecipesScreen extends ConsumerWidget {
   const RecipesScreen({super.key});
 
-  Future<void> _logout(BuildContext context, WidgetRef ref) async {
-    await ref.read(authStateProvider.notifier).logout();
-    if (context.mounted) context.go('/login');
-  }
-
   @override
   Widget build(BuildContext context, WidgetRef ref) {
     final recipesAsync = ref.watch(recipesProvider);
-    return Scaffold(
-      appBar: AppBar(
-        title: const Text('Recept'),
-        actions: [
-          IconButton(
-            tooltip: 'Profil',
-            icon: const Icon(Icons.person),
-            onPressed: () => context.go('/profile'),
-          ),
-          IconButton(
-            tooltip: 'Logga ut',
-            icon: const Icon(Icons.logout),
-            onPressed: () => _logout(context, ref),
-          ),
-        ],
+    return recipesAsync.when(
+      loading: () => const LoadingStateView(label: 'Laddar recept...'),
+      error: (error, _) => ErrorStateView(
+        message: mapErrorToUserMessage(error),
+        onRetry: () => ref.invalidate(recipesProvider),
       ),
-      body: recipesAsync.when(
-        loading: () => const Center(child: CircularProgressIndicator()),
-        error: (e, _) => Center(child: Text('Fel: $e')),
-        data: (recipes) => ListView.builder(
+      data: (recipes) {
+        if (recipes.isEmpty) {
+          return const EmptyStateView(
+            title: 'Inga recept hittades',
+            description: 'Lagg till ett recept for att komma igang.',
+          );
+        }
+
+        return ListView.builder(
           itemCount: recipes.length,
           itemBuilder: (context, index) {
             final recipe = recipes[index];
@@ -52,8 +43,8 @@ class RecipesScreen extends ConsumerWidget {
                   : null,
             );
           },
-        ),
-      ),
+        );
+      },
     );
   }
 }