Review: DeleteObjectTagging persists the tagging-timestamp internal key
but leaves the object tagless, and the outbound mapper only loaded the
key inside the user_tags-nonempty branch — the deletion's LWW timestamp
stayed at the epoch and the header was omitted, so the deletion could
never win conflict resolution on the replica. The stored key is now
loaded unconditionally; the mod_time fallback still applies only while
tags exist (MinIO parity), and a tagless object without the key keeps
the epoch default (no header). Deletion-path regression test added.
唐小鸭
77a536093e