Add enterprise export maintenance guard

[drsteinerdj]

/claim #19

Summary

Adds a self-contained enterprise-export-maintenance-guard/ reviewer artifact for Enterprise Tooling. This slice focuses on whether institutional export destinations are safe to send to before pushing research outputs to repositories, LMS, ELN, or funder systems.

It validates synthetic export jobs for:

• active destination maintenance windows
• institutional blackout calendars
• degraded destination health
• stale status evidence
• retry windows that exceed enterprise policy
• missing export-owner acknowledgement for risky timing
• embargo-sensitive payloads that should be held instead of automatically retried

The module emits deterministic SEND, DEFER, or HOLD decisions with JSON, Markdown, SVG, and MP4 reviewer artifacts.

Non-overlap

This is intentionally separate from existing #19 slices for admin dashboards, webhooks, webhook replay/redaction/schema, SSO/SCIM, repository sync SLA, API change governance, API rate limits, connector certification, funder reporting exports, data residency, vendor DPA, journal/style package provenance, token rotation, training policy, cost-center chargeback, and support entitlement.

Validation

Run from enterprise-export-maintenance-guard/:

npm run check
npm test
npm run demo
npm run demo:video

Also verified:

git diff --check
ffprobe -v error -select_streams v:0 -show_entries stream=codec_name,width,height,r_frame_rate -show_entries format=duration,size -of default=noprint_wrappers=1 enterprise-export-maintenance-guard/reports/demo.mp4

MP4 demo artifact:

• H.264
• 960x540
• 12 fps
• 4.0 seconds

No credentials, private tenant data, external APIs, live status pages, or payment systems are used.