[codex] add single-pass peer review to extract-knowhow

[ktwu01]

What changed

• add a single-pass peer review step to the extract-knowhow prompt so each generated skill is reviewed exactly once by a different AI agent family
• define the cross-agent routing explicitly for Claude Code, Codex CLI, and Gemini
• add peer review metadata to the extracted skill schema: reviewer agent, review status, and review notes
• surface peer review status and notes in the generated HTML report and include them in the generated skill draft content
• add regression coverage for the new prompt rules and report rendering path

Why

Right now extraction is effectively a single-agent generation flow. This change makes peer review a first-class part of the workflow, while preventing review loops by enforcing exactly one external review pass.

Impact

Generated skills now carry visible peer review metadata, and the extraction contract becomes clearer about when another model should review the output.

Validation

• npm test