add persistent flag --kind

use it to configure the client

internal/xair/address.go

@@ -7,3 +7,12 @@ var xairAddressMap = map[string]string{
 var x32AddressMap = map[string]string{
 	"bus": "/bus/%02d",
 }
+
+func addressMapForMixerKind(kind MixerKind) map[string]string {
+	switch kind {
+	case KindX32:
+		return x32AddressMap
+	default:
+		return xairAddressMap
+	}
+}