Add changelog entries for 2026-10 support and REST resource error

Author: lizkenyon

CHANGELOG.md

@@ -4,7 +4,9 @@ Note: For changes to the API, see https://shopify.dev/changelog?filter=api
 ## Unreleased
 - [#1443](https://github.com/Shopify/shopify-api-ruby/pull/1443) Add `ShopifyAPI::Utils::ShopValidator` (module) with `sanitize_shop_domain` and `sanitize!`.
 - [#1443](https://github.com/Shopify/shopify-api-ruby/pull/1443) `ShopifyAPI::Auth::TokenExchange.exchange_token` always uses the session token's `dest` claim, instead of the `shop` parameter, that is now deprecated. It will show a deprecation warning and the argument will be removed in the next major version.
-- Add support for 2026-07 API version
+- [#1454](https://github.com/Shopify/shopify-api-ruby/pull/1454) Add support for 2026-07 API version
+- [#1457](https://github.com/Shopify/shopify-api-ruby/pull/1457) Add support for the 2026-10 API version. REST resources for 2026-10 are not bundled yet; the GraphQL Admin API and the REST client are unaffected.
+- [#1457](https://github.com/Shopify/shopify-api-ruby/pull/1457) Referencing a REST resource for an API version whose resources aren't bundled now raises `ShopifyAPI::Errors::RestResourceNotLoadedError` (a `NameError` subclass) explaining the version gap, instead of a bare `uninitialized constant`.
 
 ## 16.2.0 (2026-04-13)
 - [#1442](https://github.com/Shopify/shopify-api-ruby/pull/1442) Add support for 2026-04 API version