How do I upload build artefacts from CI?

1. Create a key with buckets:write only (plus buckets:read if the job resumes uploads) and store it, with your Account ID, as encrypted CI secrets.
2. Give each pipeline its own key so you can revoke it alone.
3. In the job, run the complete uploader (Python or JavaScript), or the one-request upload for files up to 4 MiB.
4. Upload zips you don't want unpacked with "kind": "asset".
5. Log the returned object id so later steps can download or publish it.

Events record which key did each upload (actor.key_name).