Audited the card liveness/health system. Policy (cardSourceVisibility) is
already correct — hides only when neither CDN nor WebTorrent is healthy,
un-hides when WebTorrent flips green. Documents the real gaps (slow probes;
opaque HEAD no-cors inaccuracy for cross-origin NIP-71 CDNs; single-source
adapter dropping extra imeta) and a 3-phase plan: multi-source capture,
video-element playability probe across sources, and speed tuning. Adds
docs/video-liveness-plan.md + expands pre-launch TODO #5. Planning only.
Co-Authored-By: Claude Opus 4.8 <[email protected]>