Add robust eval center product audit contract

[c-mongan]

Summary

• add a product audit contract for Robust Eval Center coverage
• expose the eval-center dashboard UX contract from validateDashboardUx
• update the product audit doc to separate implemented eval-center controls from remaining managed isolation gaps

Verification

• npm --prefix agentops-cli test
• npm --prefix actioner test
• node agentops-cli/src/index.js product audit --json
• node agentops-cli/src/index.js demo verify --runs 50 --json
• git diff --check