Since the grants part creates a manifest's buckets after a delivery (ADR 0547), a module restarted by that
delivery can open a new state before it exists; OptionalBucket answered nil and the part never looked again
(mesh-delivery's checker and builder, state hearing, 2026-10-26). AwaitBucket binds on the server's
STREAM.CREATED advisory, or at the next use, and writes the latest value kept per key. The copied composer's
agreement test leaves that one row out: the controller's list is no longer loaded since the take-over.
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).
jschoubben