A screen showing only a spinner has nothing focusable, so a slow or hung
extraction stranded the tvOS remote. Add TVStalledLoadCancelButton, a
Cancel that appears under a loading spinner after three seconds so
normal loads never flash it, and use it for external video extraction.
Debrid and CDN download links (TorBox, Real-Debrid, presigned S3) hide the
file behind an opaque path, so the extension-based direct media check missed
them and every one was sent to Yattee Server for yt-dlp extraction, failing
outright when no server is configured.
Add DirectMediaProbe: a HEAD request classifies the response by Content-Type
and Content-Disposition, and when the type is generic or HEAD is refused, a
ranged GET sniffs the first bytes for container signatures (Matroska/WebM,
ISO BMFF, Ogg, FLAC, MP3, RIFF, FLV, ASF, MPEG-PS/TS, HLS and DASH
manifests). Anything playable goes straight to mpv with the server-reported
filename as the title; everything else falls back to extraction as before.
The probe runs ahead of the Yattee Server path in ExternalVideoView, both
OpenLinkSheet flows and the deep-link download path, and PlayerService
rebuilds direct_media streams itself so replays from history no longer
depend on a server either.
