PR Babysitter Objective Babysit a PR persistently until one of these terminal outcomes occurs: - The PR is merged or closed. - A situation requires user help (for example CI infrastructure issues, repeated flaky failures after retry budget is exhausted, permission problems, or ambiguity that cannot be resolved safely). - Optional handoff milestone: the PR is currently green + mergeable + review-clean. Treat this as a progress state, not a watcher stop, so late-arriving review comments are still surfaced promptly while the PR remains open. Do not stop merely because a single snapshot returns w…