A POST or PUT is replayed only when every errno in the cause chain is a
connect errno and the walk reached the end of the chain, and
postJSON/putJSON no longer follow redirects, so a redirect is an
ApiError that is not retried. getRetryOptions() returns a copy. New
tests pin every errno the classifier names, the cause-chain depth
limit, a chain deeper than the limit, a two-error cycle, and a fresh
deadline per attempt for every retrying entry point. The README
endpoint list is now the one place naming the requests the replay rule
covers; code comments point to it.
Model: opus-5-5