feat: add system upgrade controller

cluster/core/kustomization.yaml

@@ -4,3 +4,4 @@ resources:
 - namespaces
 - metallb-system
 - cert-manager
+- system-upgrade

cluster/core/namespaces/kustomization.yaml

@@ -4,3 +4,4 @@ resources:
 - cert-manager.yaml
 - metallb-system.yaml
 - networking.yaml
+- system-upgrade.yaml

cluster/core/namespaces/system-upgrade.yaml

@@ -0,0 +1,5 @@
+---
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: system-upgrade

cluster/core/system-upgrade/kustomization.yaml

@@ -0,0 +1,5 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+namespace: system-upgrade
+resources:
+- https://github.com/rancher/system-upgrade-controller/releases/download/v0.6.2/system-upgrade-controller.yaml