Backport of 'Sign Workhorse MCP client requests with the API JWT'
What does this MR do and why?
Backport of !247623 (merged). The senddata JWT verification shipped in 19.2.1 (gitlab-org/security/gitlab!6169) 403s every Orbit MCP tool call from Workhorse's embedded client, so Duo Agent Platform chats using Orbit hang. Clean cherry-pick of a27b7b8d, no conflicts.
Related to !247623 (merged)
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.
- 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
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- 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-eejob 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.