The control plane serves and pushes on the bus it is told to

The seams were there and nothing chose a side: serve, push, ask and build all
opened the old bus's connection and declared over its channel, whatever
MESH_BUS_NATS said. So the switch moved every host and left the control plane
unable to follow — "this control plane has no MESH_BROKER_AMQP" with the new bus
named and standing (2026-09-28). That was task 4.3 of design 28, still open.

One place now decides: connectLink reads the switch, refuses both buses named at
once, raises the new bus's streams and this controller's consumers when it is
handed the inventory, and opens the link over whichever bus it is on. Every
caller that sent a declaration or asked a tool through the old channel goes
through the server's bus instead, which the new transport has and the channel is
not. OverNats is that outbound: a declaration is a JetStream publish into the
node's own subject, an event is announced on the subject its name derives to, a
tool is request and reply on the module's tool subject.

cmd/mesh-controller/ask.go

@@ -37,7 +37,7 @@ func askCommand(ctx context.Context, args []string) error {
 		arguments = json.RawMessage(positionals[2])
 	}
 
-	server, err := link.Connect(nil, nil)
+	server, err := connectLink(ctx, nil, nil, nil)
 	if err != nil {
 		return err
 	}