Add BLADE analysis skill for benchmark report methodology

[jmabry]

Summary

Add a new BLADE analysis skill so agents can turn NeMo Gym rollout artifacts into evidence-backed benchmark reports and improvement recommendations.

Scope

• Add the skill for Claude and Codex agents.
• Include original CVDP as an opt-in, non-default example for report interpretation.
• Reference existing CVDP example rollouts in resources_servers/cvdp/data/ instead of duplicating rollout JSONL.
• Include only Nemotron 3 Super golden analysis artifacts as optional reference material.
• Keep the skill and artifacts sanitized for public repo use.

Draft PR

• Add BLADE analysis skill #1584