refactor(cart): update CartItemResource to serialize only selected variant and remove unused variant data

app/Domains/Cart/Resources/CartItemResource.php

@@ -4,7 +4,6 @@ namespace App\Domains\Cart\Resources;
 
 use App\Domains\Cart\Models\CartItem;
 use App\Domains\Catalog\Enums\InventoryPolicy;
-use App\Domains\Catalog\Models\Variant;
 use Illuminate\Http\Request;
 use Illuminate\Http\Resources\Json\JsonResource;
 
@@ -38,16 +37,14 @@ class CartItemResource extends JsonResource
             'product' => $selectedItem === null ? null : [
                 'nombre' => $selectedItem->getName(),
                 'imagen' => $imageUrl,
-                'variants' => $this->catalogItem->visibleVariants($this->variant_id)
-                    ->map(fn (Variant $variant): array => [
-                        'id' => $variant->id,
-                        'precio' => $this->formatMoney($variant->getPrice()),
-                        'stock_tecnico' => $this->catalogItem->inventory_policy === InventoryPolicy::Unlimited
-                            ? null
-                            : $variant->inventory->availableStock(),
-                        'values' => $variant->selectorOptions($this->catalogItem->itemAttributes),
-                    ])
-                    ->values(),
+                'variant' => $this->variant === null ? null : [
+                    'id' => $this->variant->id,
+                    'precio' => $this->formatMoney($this->variant->getPrice()),
+                    'stock_tecnico' => $this->catalogItem->inventory_policy === InventoryPolicy::Unlimited
+                        ? null
+                        : $this->variant->inventory->availableStock(),
+                    'values' => $this->variant->selectorOptions($this->catalogItem->itemAttributes),
+                ],
             ],
         ];
     }