Function now_stamp 

pub fn now_stamp() -> String

Now as an RFC 3339 stamp with milliseconds (2026-10-01T09:30:00.123Z): the order of records written within one second is the order they were written in, and the fixed width keeps byte order and time order the same.

use majordomus_cli::reasoning::{epoch_seconds, now_stamp};

let stamp = now_stamp();
assert_eq!(stamp.len(), "2026-10-01T09:30:00.123Z".len());
assert!(epoch_seconds(&stamp).unwrap() > 0);