feat(cart): enhance item update functionality to support variant changes and improve cart editing policies

app/Domains/Purchase/Services/Checkout/PurchaseItemSnapshotFactory.php

@@ -10,6 +10,35 @@ use Illuminate\Support\Collection;
 
 class PurchaseItemSnapshotFactory
 {
+    /** @return array<string, mixed> */
+    public function fromVariant(Variant $variant, int $quantity): array
+    {
+        $variant->loadMissing([
+            'attachments',
+            'catalogItem.attachments',
+            'definitions.itemAttribute.attribute.options',
+            'eventDates',
+            'eventDate',
+        ]);
+        $unitPrice = $variant->getPrice();
+
+        return [
+            'source_variant_id' => $variant->id,
+            'image_attachment_id' => $variant->attachments->first()?->id
+                ?? $variant->catalogItem->attachments->first()?->id,
+            'nombre' => $variant->catalogItem->nombre,
+            'descripcion' => $variant->getDescription(),
+            'slug' => $variant->catalogItem->slug,
+            'item_nombre' => $variant->getName(),
+            'variant_attributes' => $this->snapshotAttributes($variant),
+            'cantidad' => $quantity,
+            'precio_unitario' => $unitPrice,
+            'discount_total' => null,
+            'tax_total' => null,
+            'total' => $unitPrice * $quantity,
+        ];
+    }
+
     /**
      * @param  Collection<int, CartItem>  $cartItems
      * @return array<int, array<string, mixed>>