Backport of the Orbit context endpoint changes to 19.4

What does this MR do and why?

Backport of 2 Orbit context endpoint changes to 19.4. Endpoints are backported on their own, not in the daily backport.

#	MR	Change	Author	Merged
1	Add job tokens and task context to the Orbit co... (!264100 - merged)	Add job tokens and task context to the Orbit context endpoint	aalgutifan	2026-10-23 12:15 UTC
2	Cover orbit context branches flagged by underco... (!264616 - merged)	Cover orbit context branches flagged by undercoverage	dgruzd	2026-10-23 17:40 UTC

!262223 (merged) adds the context endpoint that both MRs change. It is on 19-4-stable-ee through !264304 (merged). The context expansions need GKG v0.153.0 or later.

Each commit is one git cherry-pick -m 1 -x with the same added and removed lines as the original MR (git patch-id --stable). There were no conflicts after the rebase onto 19-4-stable-ee. !264616 (merged) needs !264100 (merged): it covers code that !264100 (merged) adds.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• This MR is backporting a bug fix, documentation update, or spec fix, previously merged in the default branch. (Release manager exception requested.)
• The MR that fixed the bug on the default branch has been deployed to GitLab.com (not applicable for documentation or spec changes).
• The MR title is descriptive (e.g. "Backport of 'title of default branch MR'"). This is important, since the title will be copied to the patch blog post.
• Required labels have been applied to this merge request
  • severity label and bug subtype labels (if applicable)
  • If this MR fixes a bug that affects customers, the customer label has been applied.
• This MR has been approved by a maintainer (only one approval is required).
• Ensure the e2e:test-on-omnibus-ee job has succeeded, or if it has failed, investigate the failures. If you determine the failures are unrelated, you may proceed. If you need assistance investigating, request help in the #s_developer_experience Slack channel to confirm the failures are unrelated to the merge request.

Note to the merge request author and maintainer

If you have questions about the patch release process, please:

• Refer to the patch release runbook for engineers and maintainers for guidance.
• Ask questions on the #releases Slack channel (internal only).
• Once the backport has been merged, the commit changes will be automatically deployed to a release environment that can be used for manual validation. See after merging runbook for details.