Release v16.3.0

[lizkenyon]

Release v16.3.0

Minor release adding generated REST resource classes for API version 2026-07, client support for API version 2026-10, clearer errors for API versions without bundled REST resources, and shop-domain and token-exchange improvements. All changes are backward compatible.

Changes

• #1443 Add ShopifyAPI::Utils::ShopValidator with sanitize_shop_domain and sanitize!.
• #1443 Derive the target shop for ShopifyAPI::Auth::TokenExchange.exchange_token from the session token's dest claim. The shop argument is now deprecated and will be removed in the next major version.
• #1454 Add generated REST resource classes for the 2026-07 API version.
• #1457 Allow GraphQL Admin API and direct REST clients to target the 2026-10 API version. Generated REST resource classes for 2026-10 are not bundled yet.
• #1457 Raise ShopifyAPI::Errors::RestResourceNotLoadedError (a NameError subclass) with version-specific guidance when generated REST resources aren't bundled, instead of a bare uninitialized constant error.

Verification

• The release branch includes the current main branch, including Add shop validation #1443, Add class for 2026-07 REST API support #1454, and Add 2026-10 support and a clear error when REST resources are not bundled #1457.
• CI passes on Ruby 3.2, 3.3, and 3.4.
• A locally built 16.3.0 gem contains all 72 generated REST resource files for API version 2026-07.

Release checklist

• Bumped lib/shopify_api/version.rb to 16.3.0.
• Updated Gemfile.lock.
• Moved unreleased changes under ## 16.3.0 in CHANGELOG.md.
• After merge, tag the merge commit as v16.3.0.
• Publish the rubygems stack through Shipit.
• Verify 16.3.0 on RubyGems.