Constant MAX_CHECK_STATUS_STALE_DAYS 

pub const MAX_CHECK_STATUS_STALE_DAYS: u32 = 3650;

Upper bound on ServerSettings::check_status_stale_days (10 years). Staleness is purely a display cutoff (now - Duration::days(n) compared to a row’s recorded_at), so the ceiling just keeps that subtraction inside chrono::DateTime’s range and stops an absurd value; enforced by the PUT handler and clamped in ServerSettings::effective_check_status_stale_days.