Wire error classes we recognise on broker-proxied (OpenAI-compatible)
non-2xx responses. Superset of [VETTED_ERROR_TYPES]: it adds the
OpenAI/Kimi/xAI-style error.type / error.code values so a proxied
failure can be named via OUR static label — never the provider’s bytes.
Like humanize_api_error but surfaces a known rate-limit reset time in
the 429 message so the failure is honest rather than cryptic.
reset_hint is a human-readable duration string, e.g. "47s".
User-actionable message for a broker-proxied non-2xx response when the
(status, vetted label) pair is one we understand; None otherwise so the
caller keeps the raw provider request failed: … prefix.