Download videos, playlists, subtitles, thumbnails, chapters, and metadata with yt-dlp. Use when the user asks to save online video/audio locally, archive a playlist/channel, extract audio, fetch subtitles/transcripts, troubleshoot yt-dlp 403/signature/cookie/plugin issues, configure yt-dlp defaults, or use yt-dlp plugins such as PO token providers, Return YouTube Dislikes, DeArrow, ChromeCookieUnlock, or sample extractor/postprocessor plugins.