Save a YouTube video as a local transcript folder — transcript.md with metadata, description, chapters and top comments, plus optional contact-sheet frame cards so an agent can "see" the video. Use whenever the user shares a YouTube link/URL and wants a transcript, captions, subtitles, wants the video "abgelegt"/saved/archived, asks what a video says, or wants it "mit Bildern/Frames/Screenshots". Also use when the user just pastes a YouTube URL and says something like "transcript" or "ablegen".
