fix(rio): typed-first internode HTTP error classification (backlog#805)
classify_reqwest_error matched reqwest/hyper error text by English
substrings, brittle to library/OS-locale wording. Refactor to a pure,
testable classify_transport_error(err, is_timeout, is_connect, is_body)
that trusts structured signals first: caller timeout, then the io::Error
kind found anywhere in the source chain (typed wins over any string/body
signal so a real ConnectionRefused is never mislabeled DnsResolutionFailed),
then a DNS-only string heuristic gated behind is_connect, then body, then
Unknown.
Flip DnsResolutionFailed to retryable, mirroring MinIO IsNetworkOrHostDown
(*net.DNSError => network-or-host-down => retryable); RustFS already retries
transient DNS at endpoints.rs, and bounded retries cost at most one extra
attempt on permanent NXDOMAIN.
Swap the ecstore remote_disk non-retryable exemplar from DnsResolutionFailed
to Unknown accordingly.
Zhengchao An
da67d6d695