feat: enhance item attributes management by adding sort order; update related models, resources, and tests for visibility and ordering of variants

app/Domains/Catalog/Models/ItemAttribute.php

@@ -12,6 +12,7 @@ use Illuminate\Database\Eloquent\Relations\HasMany;
     'catalog_item_id',
     'attribute_id',
     'allow_multi_select',
+    'sort_order',
 ])]
 class ItemAttribute extends Model
 {
@@ -25,6 +26,7 @@ class ItemAttribute extends Model
             'catalog_item_id' => 'integer',
             'attribute_id' => 'integer',
             'allow_multi_select' => 'boolean',
+            'sort_order' => 'integer',
         ];
     }