Fix agent: re-request review from all reviewers after pushing changes

[ralphbean]

What happens

When the fix agent pushes changes to a PR branch, it does not re-request review from anyone. Reviewers who previously submitted reviews (whether "changes requested," "approved," or "comment only") are not notified that new changes are available for review. This can leave PRs idle when reviewers don't notice the new push.

What should happen

After the fix agent pushes changes to a PR, it should re-request review from all users and bots that have previously submitted a review on that PR. This signals to every reviewer — human and bot — that the fix agent considers its changes ready for another look.

Context

• Motivated by feat: reusable workflows (ADR 31), centralized routing (ADR 34), layered content (ADR 35) #792: a human was fixing things and pushed changes but forgot to re-request review, so the PR sat idle. The fix agent should not repeat that mistake — it should always re-request review after pushing.
• GitHub's "re-request review" mechanism (POST /repos/{owner}/{repo}/pulls/{number}/requested_reviewers) sends notifications and resets the review state for those reviewers, making it clear the PR has new changes to evaluate.
• This applies to both human reviewers and bot reviewers (e.g. fullsend-ai-review[bot]).
• Related: shim: Review→Fix dispatch uses changes_requested event instead of label-based trigger #551 (fix loop dispatch mechanism), Review bot non-standard re-review #651 (review bot re-review behavior), fullsend-ai-review bot does not revoke stale APPROVED reviews on subsequent commits #827 (stale approved reviews).

[github-actions]

fullsend triage is working on this — view logs

[github-actions]

fullsend triage is working on this — view logs

[fullsend-ai-triage]

Triage: Feature Request

This issue describes new functionality for the fix agent — automatically re-requesting review from all prior reviewers after pushing changes. This behavior has not been implemented before, so this is being classified as a feature request rather than a bug.

The request is well-specified:

• Desired behavior: After the fix agent pushes to a PR branch, call POST /repos/{owner}/{repo}/pulls/{number}/requested_reviewers for all users/bots that previously submitted a review.
• Motivation: Prevents PRs from going idle when reviewers aren't notified of new changes (as observed in feat: reusable workflows (ADR 31), centralized routing (ADR 34), layered content (ADR 35) #792).
• Scope: Applies to both human reviewers and bot reviewers.

Related open issues (not blocking, but adjacent):

• Review bot non-standard re-review #651 — Review bot re-review UX (how the review bot presents re-reviews)
• fullsend-ai-review bot does not revoke stale APPROVED reviews on subsequent commits #827 — Stale APPROVED reviews not revoked on new commits
• shim: Review→Fix dispatch uses changes_requested event instead of label-based trigger #551 — Review→Fix dispatch mechanism

These issues address related parts of the review lifecycle but do not block implementing re-request-review functionality in the fix agent.

This will be relabeled for product/engineering prioritization.