Summary

Add a non-intrusive way to launch a build job against the source branch tip of an open pull request from the PR page (not the merge-preview commit).

Agreed in issue OD-2899 (Question).

Background

Today the PR page focuses on merge verification: required jobs run against refs/pulls/<n>/merge. There is no PR-page control to run an arbitrary job against the feature branch tip. That matters for jobs that must not use a merge commit (e.g. publish/deploy from the feature branch).

UX

• Place a low-emphasis Run job… entry in the .submission side panel, below Source.
• Reuse the existing Builds-page job picker / run rules.
• Runnable jobs: any job defined in the build spec at the source tip.
• Permission: same as today’s manual run job permission.

Build association and merge gates

• Associate the launched build with the open PR (show on PR; navigate build → PR).
• Do not treat these source-branch builds as satisfying required jobs.
• Do not overwrite the PR’s merge-check build commit when launching them.
• Optionally list them under Jobs with a clear “source branch” label, separate from merge-check status.

Forks / project scope (v1)

• Same-project PRs only for source-branch runs from the PR side panel.
• Fork PRs keep today’s merge-ref / trust model.
• True fork source-branch builds (if needed) are a follow-up with explicit rules for project, secrets, and who may trigger.

Out of scope for this issue

• Changing how required-job merge-verification play buttons work.
• Fork source-project + source-branch runs.