pub fn parse_retry_after(raw: &str) -> Option<Duration>Expand description
RFC 7231 section 7.1.3 Retry-After accepts either delta-seconds
("120") or an HTTP-date ("Wed, 21 Oct 2015 07:28:00 GMT").
Anthropic emits the integer form today, but the spec leaves the
HTTP-date form open and proxies / CDNs in the path may swap shapes.
Try the integer form first; fall back to httpdate parsing and
compute the delta from now.