admit

open override fun admit(descriptor: TaskDescriptor): AdmissionTicket?

Reserve this task's lane entitlement, or defer it.

Returns a settling AdmissionTicket when the reservation succeeds; null (defer) when the lane's leaf is out of entitlement. An un-gated lane (laneToLeaf returns null, e.g. the default Lane.ROOT) is admitted immediately with a no-op ticket, touching no ledger.