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/CatalogItem.php

@@ -16,6 +16,7 @@ use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 use Illuminate\Database\Eloquent\Relations\HasMany;
+use Illuminate\Support\Collection;
 
 #[Fillable([
     'tenant_code',
@@ -170,6 +171,15 @@ class CatalogItem extends Model
         return ($this->availableStock() ?? 0) > 0;
     }
 
+    /** @return Collection<int, Variant> */
+    public function visibleVariants(): Collection
+    {
+        return $this->variants
+            ->filter(fn (Variant $variant): bool => $this->inventory_policy === InventoryPolicy::Unlimited
+                || ($variant->inventory?->availableStock() ?? 0) > 0)
+            ->values();
+    }
+
     public function getPrice(): float
     {
         return (float) $this->precio;