Add bounty completion reputation guard

[Davidrsdiaz]

/claim #15

Summary

• Add a self-contained bounty-completion-reputation-guard slice for issue Community & User Reputation System #15.
• Validate completed scientific challenge and bounty outcomes before they update researcher reputation, badges, leaderboards, citation pages, or project timelines.
• Check sponsor acceptance, prize settlement, appeal holds, IP/release finality, immutable deliverable and evaluation receipts, team split attribution, duplicate completion credit, and transparent final/provisional/blocked reputation deltas.
• Generate deterministic JSON, Markdown, SVG, and MP4 reviewer artifacts from synthetic data only, with no credentials, private repositories, bounty-platform calls, payment processors, identity providers, or live reputation systems.

Demo

• bounty-completion-reputation-guard/reports/demo.mp4

Validation

• node bounty-completion-reputation-guard/test.js
• node bounty-completion-reputation-guard/demo.js
• node bounty-completion-reputation-guard/make-demo-video.js
• node --check bounty-completion-reputation-guard/index.js
• node --check bounty-completion-reputation-guard/sample-data.js
• node --check bounty-completion-reputation-guard/test.js
• node --check bounty-completion-reputation-guard/demo.js
• node --check bounty-completion-reputation-guard/make-demo-video.js
• ffprobe confirmed H.264 1280x720, 4 seconds, 12 fps for the demo MP4.
• git diff --cached --check passed before commit.
• ASCII source scan passed for JS and README files.

AI-assisted with Codex; I reviewed and verified the generated diff and artifacts locally before submission.

[Davidrsdiaz]

/claim #15

Claim refresh for the scientific bounty completion reputation guard PR.