Preserve review provenance marker for supersede-older-reviews #63264

Problem

submit-pull-request-review with footer: always and supersede-older-reviews: true emits a gh-aw-workflow-call-id marker in the safe-output tool call, but the marker is absent from the review body later returned by GitHub's pull-request review API. The native supersession handler therefore cannot match and dismiss an older REQUEST_CHANGES review from the same workflow.

Evidence

• The rendered agent prompt required the marker.
• The safe-output MCP log recorded a submit_pull_request_review body ending with:
  <!-- gh-aw-workflow-call-id: owner/repo/test-critic-review -->
• The handler logged PR review footer mode set to "always" and PR review supersede mode enabled.
• The created GitHub review body did not contain the marker, and the earlier blocking review remained CHANGES_REQUESTED.

Expected behavior

A review created by submit-pull-request-review retains a durable workflow-specific provenance marker that supersede-older-reviews can safely use to dismiss only older blocking reviews from the same workflow.

Suggested direction

Persist provenance outside sanitized review body content, or ensure the marker survives the safe-output/GitHub review submission path. Add an integration test that creates a blocking review, posts a clean replacement review, and asserts the old review becomes DISMISSED without affecting a different workflow's review.