Attach your own metadata to orders in the API

Integration customers can now pass key-value metadata into a Sibi order at creation and read it back on Firehose events.

The createOrder and reviewOrder mutations, including the draft variants, and the Checkout UI now accept a custom metadata object. That metadata is returned on the order.updated Firehose event, so your reference IDs, job numbers, or any workflow state travel with the order from creation to fulfillment. No separate lookup table needed.