Add scientific bounty appeals ledger

[FeeeeelixWong]

@algora-pbc /claim #18

Contributes to #18.

Summary

• Adds a self-contained scientific-bounty-appeals-ledger module for the Scientific Bounty System bounty.
• Focuses on the post-evaluation appeal/dispute layer rather than another challenge intake, scoring, payout-routing, or workspace-privacy module.
• Models appeal eligibility, evidence-lock snapshots, reviewer conflict checks, response SLAs, payout holds, IP transfer guards, sponsor feedback packets, arbitration dashboard summaries, audit events, and stable digests.
• Includes sample challenge data, requirement map, tests, CLI demo, SVG demo frame, and short MP4 demo artifact.

Why this slice is distinct

Existing #18 submissions cover broad bounty systems, trust/scoring ledgers, challenge intake, payout readiness, and solver workspace privacy. This PR targets what happens after a result is contested: whether the appeal is eligible, whether evidence is locked, whether a conflicted reviewer must be replaced, whether funds should stay held, and whether IP transfer must remain blocked.

Demo

• scientific-bounty-appeals-ledger/docs/demo.mp4
• scientific-bounty-appeals-ledger/docs/demo.svg
• cd scientific-bounty-appeals-ledger && npm run demo

Demo output:

Challenge: Regional climate forecasting benchmark
Appeals tracked: 2
Payout status: partial-hold
Held amount: US$60,000
Open appeals: 1
Top action: Assign an independent reviewer to resolve conflict-of-interest concerns.
IP guards: 2
Digest: 2ab8d28a7688c0ba1fd17867ba14e1923a46cdfb5049d121d7bb5c86f7d0f26b

Verification

cd scientific-bounty-appeals-ledger
npm run check
npm test
npm run demo
ffprobe -v error -select_streams v:0 -show_entries stream=codec_name,width,height,duration -of default=noprint_wrappers=1 docs/demo.mp4
cd ..
git diff --check
git diff --cached --check
rg -n 'api[_-]?key|private[_-]?key|password|secret|token|wallet|ssn' scientific-bounty-appeals-ledger || true

Local results:

scientific-bounty-appeals-ledger tests passed
codec_name=h264
width=1280
height=720
duration=4.000000

AI-assisted with OpenAI Codex; I reviewed the implementation and local validation before submitting.

[FeeeeelixWong]

/claim #18