rig major updates

ctrl/cluster.sh

@@ -14,7 +14,7 @@
 #   KIND_CONFIG          spr's own kind config, which maps the rooms' gateway NodePorts
 #   REGISTRY_MODE=none   rooms load images straight into the node
 #   PROFILE= ADDONS=     set empty here, so rig's own ctrl/.env can never quietly
-#                        pick a profile or add addons to spr's cluster
+#   OVERLAY=             pick a profile, an overlay or addons for spr's cluster
 #
 # status stays here: it answers a question about rooms, not about the cluster.
 set -e
@@ -27,6 +27,7 @@ rig() {
     KIND_CONFIG="$SCRIPT_DIR/k8s/kind-config.yaml" \
     REGISTRY_MODE=none \
     PROFILE= \
+    OVERLAY= \
     ADDONS= \
         bash "$RIG_CTRL/cluster.sh" "$@"
 }