Hydrogen January 2026 release

The Hydrogen January 2026 release (v2026.1.0) is out. This is a quarterly API version bump to Storefront API 2026-01 and Customer Account API 2026-01.

• Updated Storefront API and Customer Account API to 2026-01 (#3434)
• The cartDiscountCodesUpdate mutation now requires the discountCodes argument. If you have custom cart discount code logic, verify your mutations include this field before upgrading.

Check out the full release notes for more details. Review the Storefront API 2026-01 changelog and Customer Account API 2026-01 changelog for other changes that may affect your storefront. And please drop your comments, feedback, and suggestions in GitHub Discussions.