Function promote_idle_for_lock 

fn promote_idle_for_lock(
    raw_idle_secs: u64,
    locked: Option<bool>,
    s: &Settings,
) -> u64

Wrapper around idle_secs_with_lock that also emits a single info line on each locked⇄unlocked transition, so the log shows why idle-based suppression suddenly engaged or disengaged. The previous-state tracker is tri-valued (unknown / unlocked / locked) so a flaky probe that returns Some(true) → None → Some(true) doesn’t generate spurious “unlocked / locked” log pairs.