/claim #18

Summary

• Adds challenge-cancellation-accountability-guard, a self-contained Scientific Bounty System slice for sponsor cancellation or no-award decisions after solver work starts.
• Evaluates cancellation reason evidence, escrow/refund state, solver notification coverage, partial-work compensation, no-award review records, IP retention, appeal-window timing, and arbitration packet readiness.
• Generates deterministic JSON, Markdown, SVG, and H.264 MP4 demo artifacts from synthetic sample data.

Why this solves part of #18

• Covers the closeout path where a sponsor cancels or no-awards a scientific bounty after solver effort exists.
• Blocks escrow refunds and IP movement until evidence, solver notice, appeal timing, compensation, and review records are complete.
• Produces a reviewer-ready hold/close packet and audit digest for arbitration and payout operations.

Sponsor decision packet

• What the bounty poster gets: a concrete cancellation/no-award guard that turns a high-dispute workflow into an auditable closeout decision with blocker codes, remediation actions, affected-solver counts, and compensation shortfall math.
• How to verify it: rerun the listed Node checks and inspect reports/summary.json, reports/cancellation-review-packet.md, reports/summary.svg, and the committed demo video. The expected demo status is hold_cancellation_close with 3 reviewed challenges, 1 held challenge, 2 ready-to-close challenges, 5 solver teams affected, 4 critical findings, and a $1,800 compensation shortfall in the synthetic case.
• Why this submission should be rewarded: competing #18 slices mostly cover intake, scoring, appeals, escrow, award transparency, benchmark leakage, data access, or evidence freeze. This submission covers the distinct sponsor decision that can happen before awards are finalized: cancellation or no-award after solver work has already started. That is a complete rewardable slice because it protects solver effort, sponsor refunds, appeal timing, IP custody, and arbitration records in one review path instead of adding another generic bounty dashboard.

Non-overlap

• This is distinct from existing intake, rubric readiness, submission privacy, prequalification, arbitration/scoring, appeals, anti-collusion, escrow settlement, payout eligibility, sponsor reliability, amendment consent, reviewer consensus, IP redaction, milestone progress, evidence freeze, data-room access, clarification freeze, award transparency, benchmark leakage, deliverable acceptance, and reproducibility-environment slices.
• Scope is limited to post-start cancellation and no-award accountability.

Scope boundaries

• Does not choose winners, score scientific submissions, run payment settlement, manage challenge intake, or replace the appeal system.
• Intentionally focuses on whether a cancellation/no-award closeout is safe to finalize or must be held for sponsor remediation.

Risk and regression notes

• The module is dependency-free and synthetic-data-only, so it does not introduce service, credential, payment, or database risk.
• The guard is conservative by design: missing cancellation evidence, premature sponsor refund, missing solver notifications, or unresolved IP custody creates a hold rather than an unsafe closeout.
• Existing project files are untouched; the change is isolated under one new directory and can be reviewed or removed without affecting the rest of the repository.

Validation

• cd challenge-cancellation-accountability-guard && npm run check
• cd challenge-cancellation-accountability-guard && npm test
• cd challenge-cancellation-accountability-guard && npm run demo
• cd challenge-cancellation-accountability-guard && file reports/demo.mp4 reports/summary.svg reports/summary.json reports/cancellation-review-packet.md
• cd challenge-cancellation-accountability-guard && mdls -name kMDItemCodecs -name kMDItemDurationSeconds -name kMDItemPixelHeight -name kMDItemPixelWidth reports/demo.mp4
• git diff --check HEAD

Demo and artifacts

• Short demo video: challenge-cancellation-accountability-guard/reports/demo.mp4
• Review summary: challenge-cancellation-accountability-guard/reports/summary.json
• Arbitration packet: challenge-cancellation-accountability-guard/reports/cancellation-review-packet.md
• Visual summary: challenge-cancellation-accountability-guard/reports/summary.svg