Add suggestion acceptance provenance guard

[zergzorg]

Summary

• Adds a self-contained collab-suggestion-acceptance-provenance-guard module for real-time collaborative editor issue Real-time collaborative research editor & interface #12.
• Validates accepted suggestions before manuscript mutation by checking quote anchors, section version hashes, protected-section lock overrides, required author approvals, unresolved reviewer replies, and notebook output freshness.
• Emits accept/defer/escalate queues, deterministic provenance digests, JSON/Markdown/SVG reports, and a short MP4 demo artifact.

Validation

• npm run check
• npm test
• npm run demo
• ffprobe -v error -show_entries format=duration,size -show_entries stream=codec_name,width,height -of default=noprint_wrappers=1 collab-suggestion-acceptance-provenance-guard/reports/demo.mp4 -> H.264, 960x540, 5s
• git diff --check
• rg -n "(password|secret|wallet|paypal|bank|passport|tax|kyc|private key|api key|token)" collab-suggestion-acceptance-provenance-guard || true -> no matches

Non-overlap

This is a narrow accepted-suggestion provenance guard. It avoids the existing broad editor foundation, operation replay, offline conflict, notebook/kernel lease, reference formatting/merge, authorship governance, freeze/recovery, discussion sidebar, autosave, round-trip fidelity, review decision, task dependency, equation/figure anchors, presence privacy/liveness, accessibility, evidence binding, embargo release, notification visibility, and LaTeX macro safety slices.

Synthetic data only; no live manuscript text, credentials, private identity data, payout details, or private dashboard data are included.

@algora-pbc /claim #12