- Server-side video thumbnails: ffmpeg-static grabs a frame at ~1s,
scales it to 480px and stores it under /uploads/thumbs/ at upload
time (direct files, remote URLs and comment attachments)
- YouTube thumbnails are downloaded once at upload time instead of
being hotlinked from i.ytimg.com on every render; remote URL kept
as fallback for legacy rows
- thumbUrl now covers video/audio/youtube/twitch in grid meta,
profile uploads and notifications
- Generated thumbnail files are removed on single/bulk delete
Generated with [Devin](https://devin.ai)
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>