feat(node-agent): Mokka Node Agent NVLink simulator

[roma-glushko]

What This PR Does

Ported NVLink simulator.

Since it's just contains of moving one topology.yaml file under the proper location we may find a better place for this code potentially completely eliminating NVLink as a simulator. However, for now, for the sake of compliance with the existing logic, we keep it as a simulator.

Why

A part of MEP0003.

Checklist

• Commits are signed off (git commit -s)
• Tests pass (go test -v -race ./...)
• Linter passes (make lint-fix)
• New code has SPDX license headers
• Documentation updated (if applicable)
• CHANGELOG.md updated (if user-facing change)

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[greptile-apps]

Greptile Summary

The change moves ComputeDomain topology staging from the setup script into a dedicated node-agent NVLink simulator.

• Registers the NVLink simulator in the node-agent lifecycle.
• Mounts the topology ConfigMap into the node-agent when topology support is enabled.
• Adds staging, update, readiness, discard, and Helm rendering coverage.

_{Reviews (4): Last reviewed commit: "Ported NVLink simulator" | Re-trigger Greptile}

[greptile-apps]

When the topology source disappears after a successful stage, Stage returns without removing the existing overlay, causing new NRI-injected workloads to receive obsolete clique IDs and cluster UUIDs. Remove the owned overlay when the source no longer exists, while propagating other os.Stat errors.

Suggested change

	if _, err := os.Stat(sourcePath); err != nil {
	s.ready.Store(true)
	return nil
	}
	if _, err := os.Stat(sourcePath); err != nil {
	if !os.IsNotExist(err) {
	return err
	}
	if err := h.Remove(h.RootPath(overlayRel)); err != nil {
	return err
	}
	s.ready.Store(true)
	return nil
	}

Knowledge Base Used:

• Node agent lifecycle and state
• Test and deployment environments