docs: clarify independent publication review

[Rook-CodeVolt]

Summary

• remove an internal review-mechanism reference from the public policy
• retain accountable human approval and independent review of factual support, omissions, tone and editorial quality
• preserve the fail-closed requirement that material waits when review is unavailable

Scope

Documentation only. Only PUBLICATION_POLICY.md changes; no workflows, code, dependencies, security controls or runtime behavior change.

Verification

• compared the branch against current main
• confirmed the approved replacement wording is exact
• confirmed the diff contains one replacement paragraph in one file

Documentation impact

This PR directly corrects the publication policy. No other documentation is affected because the review requirement and publication boundary remain unchanged.