monotonic-clock-offset-sync

Estimate a peer's clock offset from ping/pong round trips — take the peer's own processing time out before halving, weight each sample against the best round trip seen, insist the local time source is monotonic, and fall back to the uncorrected value while the estimate is not yet usable. Use when several devices must agree what time it is before they can agree where a stream is, when a group drifts apart on a…