Record the public 1.0 API that 941a7ce introduced in place of the revived store_mut backdoor: the opt-in WallClockStore trait (FoldReport, set_wall_clock, peer_time_estimate) and Node::set_wall_clock / Node::peer_time_estimate, bounded on S: WallClockStore. Updates §3's public table and Node method list and §9's fold and time-from-peers text; core still never interprets wall time. Also split the drain_events sentence into its own §3 bullet. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>