Rust/egui desktop app:
- library.rs: scans channels/<name>/ into channels + videos by filename stem
- downloader.rs: runs yt-dlp in a background thread, streams progress to the UI
- app.rs: channel sidebar, searchable video list with thumbnails, detail/description
panel, downloads panel, plays videos via mpv (falls back to xdg-open)
channels/ is gitignored (holds the downloaded media).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
