docs: add missing step in product builder guide (#13370)

www/apps/book/public/llms-full.txt

@@ -68634,6 +68634,18 @@ After that, you use the [addToCartWorkflow](https://docs.medusajs.com/references
 Next, you need to add the complementary and addon product variants to the cart. Replace the `TODO` with the following:
 
 ```ts title="src/workflows/add-product-builder-to-cart.ts" highlights={addProductBuilderToCartWorkflowHighlights3}
+// Step 4: Get cart after main product is added
+const { data: cartWithMainProduct } = useQueryGraphStep({
+  entity: "cart",
+  fields: ["*", "items.*"],
+  filters: {
+    id: input.cart_id,
+  },
+  options: {
+    throwIfKeyNotFound: true,
+  },
+})
+
 // Step 5: Add complementary and addon products
 const {
   items_to_add: moreItemsToAdd,

www/apps/resources/app/how-to-tutorials/tutorials/product-builder/page.mdx

@@ -4615,17 +4615,30 @@ After that, you use the [addToCartWorkflow](/references/medusa-workflows/addToCa
 Next, you need to add the complementary and addon product variants to the cart. Replace the `TODO` with the following:
 
 export const addProductBuilderToCartWorkflowHighlights3 = [
-  ["3", "items_to_add", "Complementary and addon items to add to the cart."],
+  ["2", "cartWithMainProduct", "Refetch the cart with the main product added."],
-  ["4", "main_item_update", "Update main product line item metadata."],
+  ["15", "items_to_add", "Complementary and addon items to add to the cart."],
-  ["30", "main_product_line_item_id", "Store the ID of the main item in the `metadata`."],
+  ["16", "main_item_update", "Update main product line item metadata."],
-  ["37", "main_product_line_item_id", "Store the ID of the main item in the `metadata`."],
+  ["42", "main_product_line_item_id", "Store the ID of the main item in the `metadata`."],
-  ["38", "is_addon", "Set `is_addon` flag for addon products."],
+  ["49", "main_product_line_item_id", "Store the ID of the main item in the `metadata`."],
-  ["48", "cart_line_item_id", "Store the line item's ID in the cart for later reference."],
+  ["50", "is_addon", "Set `is_addon` flag for addon products."],
-  ["63", "addToCartWorkflow", "Add complementary and addon products to the cart."],
+  ["60", "cart_line_item_id", "Store the line item's ID in the cart for later reference."],
-  ["72", "updateLineItemInCartWorkflow", "Update main product line item metadata with its cart line item ID."]
+  ["75", "addToCartWorkflow", "Add complementary and addon products to the cart."],
+  ["84", "updateLineItemInCartWorkflow", "Update main product line item metadata with its cart line item ID."]
 ]
 
 ```ts title="src/workflows/add-product-builder-to-cart.ts" highlights={addProductBuilderToCartWorkflowHighlights3}
+// Step 4: Get cart after main product is added
+const { data: cartWithMainProduct } = useQueryGraphStep({
+  entity: "cart",
+  fields: ["*", "items.*"],
+  filters: {
+    id: input.cart_id,
+  },
+  options: {
+    throwIfKeyNotFound: true,
+  },
+})
+
 // Step 5: Add complementary and addon products
 const {
   items_to_add: moreItemsToAdd,

www/apps/resources/generated/edit-dates.mjs

@@ -6566,7 +6566,7 @@ export const generatedEditDates = {
   "app/commerce-modules/order/order-totals/page.mdx": "2025-07-31T15:12:10.633Z",
   "app/commerce-modules/user/invite-user-subscriber/page.mdx": "2025-08-01T12:01:54.551Z",
   "app/how-to-tutorials/tutorials/invoice-generator/page.mdx": "2025-08-04T00:00:00.000Z",
-  "app/how-to-tutorials/tutorials/product-builder/page.mdx": "2025-08-14T11:21:18.409Z",
+  "app/how-to-tutorials/tutorials/product-builder/page.mdx": "2025-09-01T14:59:43.128Z",
   "app/integrations/guides/payload/page.mdx": "2025-08-21T05:24:11.537Z",
   "references/js_sdk/admin/Client/methods/js_sdk.admin.Client.getToken/page.mdx": "2025-08-14T12:59:55.678Z",
   "app/commerce-modules/order/draft-orders/page.mdx": "2025-08-26T09:21:49.780Z",