Function trim_shared 

pub fn trim_shared(
    root: &Path,
    here: &str,
    seal: &dyn Sealer,
    now_ms: i64,
) -> Result<usize, String>

The requests and outcomes kept past phonemsgs::KEPT_DAYS taken out of this device’s own files under root, those of other devices phonemsgs::LATE_DAYS later (a computer gone for good never takes its own out): the sharing then takes them out everywhere. The requests are sealed: each opened to read its time, one that does not open kept.