Remove quantityAvailable from product variant query

The Storefront API only returns ProductVariant.quantityAvailable when the
app has the unauthenticated_read_product_inventory scope, and nothing in
the template reads the field — availableForSale already drives stock state.

Also bumps the example Shopify API version to 2026-10 and drops the pinned
packageManager field from package.json.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FaxyZTjAyd7UXK8xpQpF7o

.env.example

@@ -1,7 +1,7 @@
 # Shopify Storefront
 NEXT_PUBLIC_SHOPIFY_DOMAIN=mock.shop
 # NEXT_PUBLIC_SHOPIFY_PUBLIC_ACCESS_TOKEN=
-# NEXT_PUBLIC_SHOPIFY_API_VERSION=2026-07
+# NEXT_PUBLIC_SHOPIFY_API_VERSION=2026-10
 
 # Store assistant — set to 1 to show the Ask launcher; anything else hides it
 NEXT_PUBLIC_ENABLE_AI=0

graphql/products.ts

@@ -49,7 +49,6 @@ export const ProductFragment = gql(`
           id
           title
           availableForSale
-          quantityAvailable
           selectedOptions {
             name
             value

package.json

@@ -53,6 +53,5 @@
         "@types/react": "^19",
         "@types/react-dom": "^19",
         "typescript": "^5.7.3"
-    },
-    "packageManager": "yarn@4.18.0+sha512.fcb8716fe7cd0eece141ffc18b92193a9df9204c1ba83189c288835223fc0bbe64af473bab0d5e9927a7daeb5caf2bb07eb2787cc9338ca040ea125f2a1f2f7e"
+    }
 }