The controller is not placed and its assignments mirror is frozen (ADR
0590). artifact-store-tools already answers through the seat's holder, so
its controller client goes. mesh-provisioner-client reads the seat
mesh-placement's placement, which its account is granted whole: a module
placed here stays while the seat holds no plan of it, filled from its last
plan, and leaves only when neither names it (issue 1126 B12).
Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL