rollout check dials the bus the way the mesh does

The probe connected bare, and a bus that requires TLS and a user refused it at the handshake —
so the check reported the standing server as absent. It now dials with the controller's own
credential and pin, which is the one fact the check is there to report.

cmd/mesh-controller/rollout.go

@@ -127,9 +127,13 @@ func readinessOf(ctx context.Context, inv *inventory.Inventory) (broker.Readines
 	if address != "" {
 		// One dial, briefly. "Is it answering" is the one fact records cannot hold, and a mesh about
 		// to move onto a server that is not there should hear it here rather than afterwards.
-		if conn, err := nats.Connect(broker.BareAddress(address), nats.Timeout(5*time.Second)); err == nil {
+		//
+		// **Dialled the way the mesh dials it** — credential and pin — because a bare connect to a
+		// bus that requires TLS and a user fails at the handshake, and the check then reported a
+		// standing server as absent (seen live, 2026-09-28).
+		if js, err := broker.Dial(address, nats.Timeout(5*time.Second)); err == nil {
 			state.ServerStanding = true
-			conn.Close()
+			js.Close()
 		}
 	}