pub fn spawn(
hosts: Arc<Hosts>,
operator: Arc<Operator>,
vapid: Arc<VapidKey>,
egress: &Egress,
) -> PushExpand description
Start the collector’s delivery: a queue, and a task draining it through
egress’s public-only client (kernel spec §6, §7.1: Web Push never
reaches a private address). The queue’s sending end is AppState::push.