pub fn format_run_duration(
started_at: DateTime<Utc>,
finished_at: Option<DateTime<Utc>>,
) -> StringExpand description
Format a run duration, using finished_at if available, otherwise live from now.
When finished_at is Some, computes a fixed duration finished_at - started_at.
When finished_at is None, falls back to Utc::now() - started_at (live counter).