feat: minikube addon for NRC

Node Readiness Controller supports a control-plane co-located / static-pod deployment model that could be preferred for non-disruptive deployments. A [minikube addon](https://minikube.sigs.k8s.io/docs/commands/addons/) will give us a way to test this as a lifecycle-managed addon path where NRC runs before user workloads after the control plane.

Minikube also will help our developer environments eg. for features in our roadmaps such as GPU/TPU node simulation for device-driver readiness related testing is very enabling with minikube vs kind. It'll also help with testing more agentic use-cases in the future with support for running gVisor / kata containers.

This feature will give a `minikube start --addons=nrc` as a one-liner for anyone looking to test / consume NRC.

ref:
- How to add a new addon: https://minikube.sigs.k8s.io/docs/contrib/addons/