Add AI-assisted contribution disclosure guard

[attaboy11]

@algora-pbc /claim #15

/claim #15

Summary

• add a self-contained AI-assisted contribution disclosure guard for the Community & User Reputation System bounty
• audit reputation-bearing contributions for AI disclosure, human verification, generated-text signals, provenance, review quality, and CRediT-role evidence
• generate deterministic JSON, Markdown, SVG, and MP4 reviewer artifacts from synthetic data only

Scope distinction

This is a distinct reputation-credit slice: it decides whether AI-assisted work should be allowed, reduced, or held before it affects badges, leaderboards, reputation points, or contribution credit. It does not overlap with the existing review-abuse, conflict-of-interest, workload, identity, credit, badge, or scientific-bounty-completion guards.

Validation

• node ai-contribution-disclosure-guard/test.js
• node ai-contribution-disclosure-guard/demo.js
• node ai-contribution-disclosure-guard/render-video.js
• node --check ai-contribution-disclosure-guard/index.js
• node --check ai-contribution-disclosure-guard/sample-data.js
• node --check ai-contribution-disclosure-guard/test.js
• node --check ai-contribution-disclosure-guard/demo.js
• node --check ai-contribution-disclosure-guard/render-video.js
• git diff --check
• ffprobe -v error -select_streams v:0 -show_entries stream=pix_fmt,width,height -show_entries format=duration,size -of default=nw=1 ai-contribution-disclosure-guard/reports/demo.mp4

MP4 metadata: width=960, height=540, pix_fmt=yuv420p, duration=4.000000, size=24164.

[attaboy11]

@algora-pbc /claim #15

PR #510 is the submitted solution for issue #15. The PR body already includes /claim #15, validation commands, and MP4 demo metadata.