Rate-limited requests

A request over a rate limit (Rate limits) gets 429 with the usual envelope and the code rate_limited:

HTTP/1.1 429 Too Many RequestsRetry-After: 42RateLimit-Policy: "default";q=5;w=3600RateLimit: "default";r=0;t=42{ "error": { "code": "rate_limited", "message": "Too many requests.", "request_id": "req_0b1e…" } }

Retry-After gives the seconds to wait. RateLimit and RateLimit-Policy are the standard headers of the IETF draft draft-ietf-httpapi-ratelimit-headers: the limit's requests (q) and window in seconds (w), and none left (r=0) until t seconds from now. The failure's wording for people comes from translations, as every failure's does, and is in the per-locale failure export (OpenAPI).