- CDN probe no longer downloads 64KB of video (or even a variant
playlist): one small master-playlist fetch proves reachability.
State stays OK/DEGRADED, kbps is no longer measured, and the pill/
panel only show a rate when one exists.
- hianime: 5x getSourcesNew re-roll -> 1 attempt. The enc payload is
deterministic per data-id (observed identical across calls), so
re-rolling only hammered the provider.
- anikoto: 2x re-roll -> 1 attempt per server, same reason.
Kept: idle-gated + 30-min degraded backoff from the previous commit,
the single _get retry (protects real user playback from CF blips),
and the origin page check (the 'down' signal). Net upstream traffic is
now what an actual viewer would generate, nothing more.