Multi-version previews for every version + Jellyfin off-media trickplay

New

• Jellyfin: store trickplay off the media drive — keep preview thumbnails in Jellyfin's own config folder instead of next to your media files (opt-in, per server). (#265)

Fixes

• Multi-version media now gets previews for every version (e.g. a 1080p + a 4K file), not just one — on Plex and Jellyfin, across library scans, Radarr/Sonarr webhooks, and native webhooks. (#269, #271, #272)
• Jellyfin off-media trickplay now registers instantly instead of only appearing after the next library scan. (#272)
• The Jellyfin "config folder" setting now validates your path — confirms it exists, is writable, and is actually Jellyfin's config dir — both in Setup Health and live as you type. (#274, #275)

Heads-up

• The old Docker image stevezzau/plex_generate_vid_previews has been retired and no longer receives updates. If you're still on it, change your compose image: to stevezzau/media_preview_generator and re-pull — settings and volumes carry over unchanged. (#276)