pub fn format_transport_error(err: &Error) -> StringExpand description
Flatten an anyhow::Error source chain into a single human-readable
transport-error line for the reason field in wire push --json and
for stderr surfaces. Classifies the topmost cause (TLS error,
DNS error, connect timeout, read timeout, HTTP error) so a
silent failure no longer leaks past the user as a bare URL.
v0.5.13 rule 1 of the network-resilience doctrine — see issue #6.