Function extract_identity 

pub fn extract_identity(headers: &HeaderMap, peer: Option<SocketAddr>) -> String

2026-09-26: The rate-limit key, first match wins: bearer:<hash> for a non-empty Authorization: Bearer token, xff:<ip> for the first non-empty X-Forwarded-For entry (taken as sent, not validated), then peer:<ip>, or peer:unknown without a peer address. rate_limit_middleware (main_modules/middleware.rs) keys the limiter with it.