fixes before build

lib/models/shopping_list.dart

@@ -7,6 +7,7 @@ class ShoppingList {
     required this.name,
     required this.itemCount,
     required this.checkedCount,
+    required this.createdAt,
     required this.updatedAt,
   });
 
@@ -14,6 +15,7 @@ class ShoppingList {
   final String name;
   final int itemCount;
   final int checkedCount;
+  final DateTime createdAt;
   final DateTime updatedAt;
 
   factory ShoppingList.fromMap(Map<String, Object?> map) {
@@ -22,6 +24,9 @@ class ShoppingList {
       name: map['name']! as String,
       itemCount: (map['item_count'] as num?)?.toInt() ?? 0,
       checkedCount: (map['checked_count'] as num?)?.toInt() ?? 0,
+      createdAt: DateTime.parse(
+        (map['created_at'] ?? map['updated_at'])! as String,
+      ),
       updatedAt: DateTime.parse(map['updated_at']! as String),
     );
   }