Serve the read verbs on the serving controller's own connection, and name every connection

Each verb ran as a process that dialled the bus, so hundreds of short
connections an hour, all named mesh-controller, hid any client reconnecting
in a loop (hq issue 327). D15 now says a user whose connections keep dropping.

cmd/mesh-controller/push.go

@@ -219,6 +219,8 @@ func serve(ctx context.Context) (err error) {
 	}
 	// The hand-act log is counted for `status` on this connection rather than a new one a minute.
 	handActConn = bus.Conn
+	// And everything else this controller does on the bus for a moment (novox/hq issue 327).
+	servingBus.Store(server.JetStream())
 	// And says when it replaced a value given by hand (novox/hq ADR 0228).
 	givenEvents = bus
 	// And a pull request's merge check, asked when the forge announces its head and said when judged