Agent Skills: github-ci-fix

Use when a user asks to publish, debug, or fix a GitHub change until the PR is ready to merge. Create or reuse the PR, diagnose GitHub Actions failures with `gh`, address active merge-blocking review comments autonomously when safe, and stay in a PR-to-mergeable loop until required checks are green and no fixable blocker remains. After the PR is ready to merge, run `session-introspection` to capture anti-recurrence controls.