Add reputation review abuse guard

[vondutchi]

/claim #15

Summary

• Add reputation-review-abuse-guard/, a distinct Community & User Reputation System slice for deciding whether peer-review activity should count toward reputation and leaderboard updates.
• Detect reciprocal review links, shared-affiliation conflicts, burst low-effort/high-delta reviews, anonymous-review identity leakage, and endorsement-cluster farming signals.
• Emit deterministic reviewer artifacts in JSON, Markdown, SVG, and MP4 form using synthetic data only.

Scope Boundaries

This is synthetic demo data only. It does not call identity providers, private user profiles, live reputation ledgers, payment systems, credentials, or SCIBASE production services.

This scope is intentionally separate from existing #15 slices such as broad reputation scoring, contributor credit graphs, peer-review templates, profile dashboards, badge systems, leaderboards, or generic community features.

Demo

• reputation-review-abuse-guard/reports/demo.mp4

Validation

• node reputation-review-abuse-guard/test.js
• node reputation-review-abuse-guard/demo.js
• node reputation-review-abuse-guard/render-video.js
• ffprobe confirmed H.264, 960x540, 5 seconds, 120 frames for the demo MP4.
• node --check reputation-review-abuse-guard/index.js
• node --check reputation-review-abuse-guard/sample-data.js
• node --check reputation-review-abuse-guard/test.js
• node --check reputation-review-abuse-guard/demo.js
• node --check reputation-review-abuse-guard/render-video.js
• git diff --cached --check

No payout details, secrets, tokens, cookies, or private account information are included in this PR.