[BUG] Verification steps use a label selector that only matches the static pod example

[Ujjwal-Gowda]

Is your feature request related to a problem or existing issue? Please describe.

The verification steps in the installation guide tell the reader to find the
controller pods with:

kubectl get pods -n ${NAMESPACE} -l component=node-readiness-controller
kubectl logs -n ${NAMESPACE} -l component=node-readiness-controller

component=node-readiness-controller is only set by
examples/static-pod/node-readiness-controller.yaml. Grepping the repository,
that example is the only place the label appears outside the docs.

The other deployment options label their pods differently:

• release manifests and Kustomize (config/manager/manager.yaml):
  control-plane=controller-manager and app.kubernetes.io/name=nrrcontroller
• Helm chart (charts/nrr-controller/templates/_helpers.tpl):
  app.kubernetes.io/name=nrr-controller, app.kubernetes.io/instance=<release>
  and control-plane=controller-manager

Neither sets a component label, so both verification commands return nothing.
kubectl get pods prints "No resources found" and kubectl logs prints an
error about no matching pods, neither of which hints that the selector itself
is the problem. Someone whose install worked fine can reasonably conclude that
it did not.

I confirmed this on a kind cluster: after installing the chart,
-l component=node-readiness-controller matches 0 pods, while
-l app.kubernetes.io/name=nrr-controller and
-l control-plane=controller-manager both match the running pod.

Describe the solution you'd like

Add a ${SELECTOR} placeholder next to the existing ${NAMESPACE} one and
list the value for each deployment option, so the commands work regardless of
how the controller was installed.

Describe alternatives you've considered

Adding a component label to the chart and the Kustomize base so one selector
works everywhere. That changes the deployment's label set rather than the docs,
and the pod labels of an installed release are not something to change lightly,
so documenting the difference seemed like the smaller step. Happy to go the
other way if you would prefer the labels unified.

I have the docs change ready, could I be assigned?

[Ujjwal-Gowda]

/assign

[tejassinghbhati]

Heads up, I briefly changed this selector in #388 before spotting your issue, and have reverted it so it is yours.

Your read is more accurate than mine was. I had assumed nothing set the label at all, and missed that the static pod example sets it and is the only thing that does. Worth noting for whatever you land: that pod has component and tier and no control-plane label, so a single replacement selector cannot cover all three install paths.