Add demo recording and expanded evidence

[Jason-Doyle]

Summary

• add a reproducible Playwright and ffmpeg capture command
• add the release screenshot and link it to the v0.1.0 recording
• expand retained fan-out evidence from three to ten scenarios per scale
• report same-snapshot Jev versus local outcomes without claiming superiority

Validation

• npm run validate
• npm audit --audit-level=low
• npm run capture:demo