Add bounty submission quarantine guard

[vondutchi]

/claim #18

Summary

• Add bounty-submission-quarantine-guard/, a distinct Scientific Bounty System slice for deciding whether solver submission packages are safe and complete enough to reach reviewers or sponsors.
• Validate manifest completeness, artifact hash coverage, unsafe artifact flags, sponsor visibility gates, reviewer-safe previews, and IP handoff statements.
• 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 execute solver files, call storage providers, expose sponsor data, process payment details, use credentials, or contact SCIBASE production services.

This scope is intentionally separate from existing #18 slices such as challenge intake, scoring/arbitration, payout routing, evidence freeze, anonymous review packets, prequalification, data-use agreements, closeout, reviewer workload, deadline fairness, and package security scanning.

Demo

• bounty-submission-quarantine-guard/reports/demo.mp4

Validation

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

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