feat: Implement inventory policy for product variants

- Introduced InventoryPolicy enum to manage tracked and unlimited inventory types.
- Updated ProductVariant model to include inventory_policy and cantidad_vendida attributes.
- Modified addItem and updateItem methods in Cart to check available quantity based on inventory policy.
- Added migration to include inventory_policy and cantidad_vendida in productos_variantes table.
- Enhanced tests to validate inventory behavior for both tracked and unlimited policies.
- Updated various request and resource classes to handle new inventory fields.

app/Domains/Catalog/Services/ProductService.php

@@ -3,6 +3,7 @@
 namespace App\Domains\Catalog\Services;
 
 use App\Domains\Attachable\Services\AttachmentService;
+use App\Domains\Catalog\Enums\InventoryPolicy;
 use App\Domains\Catalog\Models\Attribute;
 use App\Domains\Catalog\Models\Product;
 use App\Domains\Catalog\Models\ProductVariant;
@@ -28,7 +29,8 @@ class ProductService
             $attributeIds = $data['attribute_ids'] ?? [];
             $images = $data['images'] ?? [];
             $stock = $data['stock'] ?? 0;
-            unset($data['attribute_ids'], $data['images'], $data['stock']);
+            $inventoryPolicy = $data['inventory_policy'] ?? InventoryPolicy::Tracked->value;
+            unset($data['attribute_ids'], $data['images'], $data['stock'], $data['inventory_policy']);
 
             /** @var Product $product */
             $product = Product::query()->create([
@@ -45,6 +47,7 @@ class ProductService
             // Create default variant with stock
             $this->createVariant($product, [
                 'stock' => $stock,
+                'inventory_policy' => $inventoryPolicy,
                 'is_placeholder' => true,
                 'definitions' => [],
             ]);
@@ -179,6 +182,7 @@ class ProductService
             if ($product->variants()->count() === 0) {
                 $product->createVariant([
                     'stock' => 0,
+                    'inventory_policy' => InventoryPolicy::Tracked->value,
                     'is_placeholder' => true,
                     'definitions' => [],
                 ]);
@@ -327,13 +331,13 @@ class ProductService
 
         $selectedVariant = $variantId !== null
             ? $product->variants->firstWhere('id', $variantId)
-            : $product->variants->first(fn (ProductVariant $variant) => $variant->stock_tecnico > 0);
+            : $product->variants->first(fn (ProductVariant $variant) => $variant->isAvailableForSale());
 
         if ($variantId !== null && $selectedVariant === null) {
             throw new NotFoundHttpException('Product variant not found for product.');
         }
 
-        if ($variantId !== null && $selectedVariant->stock_tecnico <= 0) {
+        if ($variantId !== null && ! $selectedVariant->isAvailableForSale()) {
             throw ValidationException::withMessages([
                 'variant_id' => 'La variante seleccionada no tiene stock.',
             ]);