The bus account has JetStream, and the control plane's client has its own inbox

Two refusals the first live connections met. A user in the MESH account was told
"JetStream not enabled for account" the first time it bound a consumer: with
accounts defined, JetStream is enabled per account, not only globally — the
account's setting, which the mesh owns, not the server's block, which it does not.
And the control plane's client used a random inbox prefix where it is granted
exactly _INBOX.<its user>.>, so the server's first answer could not reach it. The
prefix now follows from the user in the URL, for every principal that dials so.

internal/broker/users_test.go

@@ -186,7 +186,13 @@ func TestWhatTheMeshWritesIsUsersAndNothingAboutTheServer(t *testing.T) {
 	}
 	// None of the server's own settings. Each of these in the mesh's file is a value the controller
 	// would then own, and the module could no longer change its own image without the mesh agreeing.
-	for _, absent := range []string{"port:", "http:", "jetstream", "tls {", "store_dir", "cert_file"} {
+	// `jetstream {` is the server's block (its store, its limits); `jetstream: enabled` inside the
+	// account is the account's, and the mesh owns the account — a user in it is told "JetStream
+	// not enabled for account" without it (2026-09-28).
+	if !strings.Contains(got, "jetstream: enabled") {
+		t.Errorf("the account does not enable JetStream, so no user in it can bind a consumer")
+	}
+	for _, absent := range []string{"port:", "http:", "jetstream {", "tls {", "store_dir", "cert_file"} {
 		if strings.Contains(got, absent) {
 			t.Errorf("the accounts file contains %q, which belongs to the module that raises the "+
 				"server, not to the mesh", absent)