test(checkpoint): cover the background upload's untested paths; order-based waits
Commit
peyton-altyesterday
- Real git push --porcelain output for the push-race pattern.
- The background_checkpoint_upload opt-out, in settings and in effect.
- status: 'uploading in the background', the stop-reason line and JSON.
- RunPushThenUploadCheckpoints (trail create's protocol, moved into strategy) through a real git push and hook, for a refused and an accepted push.
- The worker keeps its notices and SSH/unreachable hints for the next push.
- A Windows-selected wait test (lookup, fingerprint, handle wait).
- A canary scenario with the background upload left on.
- Wait tests assert that the wait ended after the push exited rather than elapsed-time bounds, so a loaded machine cannot fail them.
Co-Authored-By: Claude Opus 5.5 noreply@anthropic.com Entire-Checkpoint: 01M6MJMXV14NRP12MAAQB72TK0