Add peer review assignment governance module

[zhengjynicolas]

/claim #15

Summary

• Adds a self-contained peer-review assignment governance module for the Community & User Reputation System.
• Scores reviewer eligibility using expertise, reputation/trust, workload, and conflict-of-interest signals.
• Blocks hard COIs before ranking, marks medium-risk disclosures for chair review, masks selected reviewers with blind labels, and emits an audit digest for reproducibility.
• Includes synthetic sample data, a requirement map, local tests, and a real terminal walkthrough demo video.

Demo

• Video: https://github.com/zhengjynicolas/SCIBASE.AI/raw/codex/review-assignment-governance-15/peer-review-assignment-governance/docs/review-assignment-demo.mp4

Verification

cd peer-review-assignment-governance
npm run check
npm test
npm run demo
ffprobe -v error -select_streams v:0 -show_entries stream=codec_name,width,height,avg_frame_rate,nb_frames,duration -of default=noprint_wrappers=1 docs/review-assignment-demo.mp4