Add prepaid compute credit breakage guard

[ethanmillerinvestments-code]

Summary

• Add a focused prepaid compute credit breakage guard for issue Revenue Infrastructure #20.
• Classify AI compute/top-up credit lots as breakage-ready, notice-due, refund liability, finance hold, protected, or usable.
• Emit deterministic JSON, Markdown, SVG, and MP4 reviewer artifacts under prepaid-compute-credit-breakage-guard/reports/.

Non-overlap

This is not another generic billing ledger, metering/idempotency guard, payment webhook/failover guard, collections module, dispute module, tax control, storage-overage check, plan-proration guard, or account-transfer slice. It focuses only on prepaid AI compute credit expiration, customer notice, refund rights, grant protections, and breakage-recognition readiness.

Validation

• npm run check
• npm test
• npm run demo
• ffprobe -v error -show_entries format=duration,size -show_entries stream=codec_name,width,height,pix_fmt -of default=noprint_wrappers=1 reports/demo.mp4
• git diff --check
• git diff --cached --check
• Disclosure scan for payment/private-key terms found only the intentional no-live-payment note in requirements-map.md.

/claim #20