GitHub stale CI pull request closer

This deterministic scheduled automation scans every open, non-draft pull request in its configured repositories. It reads the required status checks from the GitHub rules that apply to the pull request's base branch.

• After required CI remains failing for seven days, it posts one marked warning.
• After seven more days, it closes the pull request only when required CI still fails and the author has neither pushed nor commented since the warning.
• Passing or pending CI, a draft conversion, closure, merge, or author follow-up cancels the pending close. Continued failure starts a fresh warning window.

The automation creates no agent or conversation. Configure a repository-scoped fine-grained PAT with Metadata: Read, Actions: Read, Commit statuses: Read, Issues: Read and Write, and Pull requests: Read and Write. The token also needs read access to repository rules. Package scripts/worker.py as worker.py and the shared skills/github/scripts/github_client.py as github_client.py.