Function classify_sender 

fn classify_sender(
    name: &str,
    candidates: &[SenderCandidate],
    now_ms: i64,
) -> VerifySenderVerdict

Pure verdict computation over already-fetched discovery data — see handle_muxspect_verify_sender for the IO/fetch boundary this composes with. candidates must already be in tier-priority order (host, then cross-channel, then lan, then wan — most-trusted first).

Among all case-insensitive name matches (a name can legitimately appear on more than one tier, or more than once within cross-channel if several channels registered it), prefers the first NON-stale match in tier-priority order; only falls back to a stale match if every match is stale. Picking the literal first match regardless of staleness (an earlier version of this function) could report stale even when a later, live entry for the same sender existed (codex review on PR #2702, P2).