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

flutter/lib/features/recipes/data/recipe_repository.dart

@@ -1,5 +1,5 @@
-import 'dart:convert';
 import '../../../core/api/api_client.dart';
+import '../../../core/api/api_exception.dart';
 import '../domain/recipe.dart';
 
 class RecipeRepository {
@@ -8,13 +8,26 @@ class RecipeRepository {
   RecipeRepository(this._api);
 
   Future<List<Recipe>> fetchRecipes({String? token}) async {
-    final response = await _api.get('/recipes', token: token);
-    if (response.statusCode != 200) {
-      throw Exception('Failed to load recipes: ${response.statusCode}');
+    try {
+      final data = await _api.getJson('/recipes', token: token);
+
+      if (data is! List) {
+        throw const ApiException(
+          type: ApiErrorType.unknown,
+          message: 'Ogiltigt svar fran servern.',
+        );
+      }
+
+      return data
+          .map((e) => Recipe.fromJson(e as Map<String, dynamic>))
+          .toList();
+    } on ApiException {
+      rethrow;
+    } catch (_) {
+      throw const ApiException(
+        type: ApiErrorType.network,
+        message: 'Kunde inte hamta recept.',
+      );
     }
-    final List<dynamic> data = jsonDecode(response.body) as List<dynamic>;
-    return data
-        .map((e) => Recipe.fromJson(e as Map<String, dynamic>))
-        .toList();
   }
 }