Function live_gauges 

pub(crate) fn live_gauges(
    registrations: &[AgentRegistration],
    is_live: impl Fn(&str) -> bool,
    has_row: impl Fn(&str) -> bool,
) -> (usize, usize)

The two live gauges over registrations: (tokenless_or_unknown, unidentified). An agent with a row whose process is not known to carry a token counts toward the first; an agent with no row (a quick-launch pane — outside the identity system, §6.5.6) toward the second. A registration without a UID is not taken as row-less on its word: a block driven only through agent.send registers without one although it has a row, so has_row asks the store. is_live filters out registrations whose block no longer runs anything here, so a stale registration cannot hold the gauge up.