The controller ended (ADR 0590): nothing consumes what nodes report on CONTROL, so the mesh no
longer declares the stream, which would make it again before its removal; MeshConsumers is empty,
the controller's consumers and the events it followed go, and the lease holder's reading
(LeaseHolder, LeaseHandedAway) with them. Only the consumers' names stay, for the removal of the
leftovers and the watchman's read of whether controller still stands. Issue 1126 B3b.
Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL
The grants part composes the bus's user list with the composer the controller uses (ADR 0547 §5), copied rather than
moved: the controller is not changed and keeps its own until it loses the lease. Left out: the bus client, the broker's
address from the environment and the client's two methods; the lease's two subjects are copied in.
One table test holds the copy to four meshes' lists and the server golden, written by the controller's own
internal/broker from the same fixtures (testdata/controller-user-lists.json).