Two consecutive publish-libs runs died on runner-side CF API flakiness (a 502
mid-put, then 'terminated' on the first probe). Gets and puts now retry with
backoff; a definitive missing-object error still returns null immediately.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011CC8aAnUUHcnHy3QCJtUwb