feat(checkout): route carts to replacement variants

app/Domains/Cart/Models/Cart.php

@@ -400,6 +400,17 @@ class Cart extends Model
                 ]);
             }
 
+            if ($catalogItem->bundleComponents()
+                ->whereNotNull('component_variant_id')
+                ->whereHas('variant', fn ($query) => $query
+                    ->whereNotNull('sales_disabled_at')
+                    ->orWhereNotNull('replaced_by_variant_id'))
+                ->exists()) {
+                throw ValidationException::withMessages([
+                    'catalog_item_id' => [__('api.cart.bundle_component_unavailable')],
+                ]);
+            }
+
             return $catalogItem;
         }
 
@@ -430,6 +441,12 @@ class Cart extends Model
             throw new NotFoundHttpException('Variant not found for catalog item.');
         }
 
+        if (! $variant->isSellable()) {
+            throw ValidationException::withMessages([
+                'variant_id' => [__('api.cart.variant_unavailable')],
+            ]);
+        }
+
         $inventory = $this->resolveInventory($variant->inventory_id, $lockForUpdate);
         $variant->setRelation('catalogItem', $catalogItem);
         $variant->setRelation('inventory', $inventory);