Trigger CI checks on manual review

[derekmisler]

Summary

This PR adds GitHub Checks API integration to all three CI workflows so that manually triggered reviews and PR description generation are surfaced as proper check runs on the PR's commit. Previously, these workflows ran silently without any visible check status on the PR; now they create a check run at the start and update it to success, failure, or cancelled upon completion.

Changes

• .github/workflows/pr-describe.yml: Added checks: write permission, a Create check run step at job start (named Generate PR Description), and an Update check run step (runs always()) to finalize the check status.
• .github/workflows/review-pr.yml: Same pattern — added checks: write, creates a PR Review check run using the resolved pr-number input or issue.number, and updates it on completion.
• .github/workflows/self-review-pr.yml: Same pattern as review-pr.yml — adds checks: write, creates and finalizes a PR Review check run tied to the PR's head_sha.

How to Test

• Open a PR and manually trigger one of the review workflows (e.g., via a comment or workflow_dispatch); a PR Review or Generate PR Description check should appear on the PR's Checks tab showing in_progress and then resolve to success or failure.
• Cancel a running workflow mid-flight and verify the check run resolves to cancelled rather than hanging as in_progress.
• Confirm the check is attached to the correct commit SHA (the PR head, not the base branch).

[derekmisler]

/describe

[docker-agent]

✅ PR description has been generated and updated!