Add challenge reviewer workload SLA guard

[shaiananvari8]

@algora-pbc /claim #18

Summary

• Adds a self-contained challenge-reviewer-workload-sla-guard module for the Scientific Bounty System.
• Evaluates reviewer availability, blackout windows, stale activity, open assignment load, weekly review capacity, rubric-criterion expertise coverage, critically stale challenge reviews, and arbitration backup readiness before scoring or award release.
• Emits deterministic JSON, Markdown, SVG, and short demo-video artifacts with a SHA-256 audit digest from synthetic data.

Scope

This is a challenge reviewer workload and SLA capacity guard. It is distinct from the existing intake, rubric-readiness, scoring/arbitration ledger, reviewer consensus, review-integrity, appeals, anti-collusion, payout eligibility, data-room access, benchmark leakage, cancellation/no-award, license/dependency, human-subjects, withdrawal, embargo-release, evaluator-calibration, and community reputation review-workload slices.

Validation

• cd challenge-reviewer-workload-sla-guard && npm run check -> passed
• cd challenge-reviewer-workload-sla-guard && npm test -> challenge-reviewer-workload-sla-guard tests passed (4)
• cd challenge-reviewer-workload-sla-guard && npm run demo -> generated JSON/Markdown/SVG artifacts; status hold_review_window, blockers 9, warnings 3
• cd challenge-reviewer-workload-sla-guard && npm run demo:video -> generated reports/demo.avi
• Demo video container sanity check -> RIFF/AVI, 480x270, 12s, 2fps, 9,332,016 bytes
• git diff --check -> passed
• git diff --cached --check -> passed
• rg -n "(password|secret|wallet|paypal|bank|passport|private key|api key)" challenge-reviewer-workload-sla-guard -> no matches

Safety

Synthetic data only. No credentials, private reviewer records, solver identities, payment rails, identity-provider calls, email sends, private challenge workspaces, external APIs, or live challenge mutations are used.

AI-assisted with OpenAI Codex; I reviewed and locally verified the diff before submitting.