The .versions lookup retried every error through the full backoff
ladder, so a missing key spent 12.7s (8 attempts, 100ms..6.4s) before
the pre-versioning fallback could answer. NotFound is an answer, not a
transient failure: gate the retries on isRetryableFilerErr, the same
classifier retryFilerOp already uses, which also stops retrying for
callers whose context is canceled or past its deadline.
GetObject already treats NotFound on .versions/ as definitive; this
brings the retention/tagging/ACL/attributes/delete/copy paths that go
through getLatestObjectVersion in line with it.
Claude-Session: https://claude.ai/code/session_01FquvGtTD2zA3uMZGQHAuV4
Chris Lu
4c9cbf72bc