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