SvelteKit web frontend for yt-dlp and ffmpeg. Paste a YouTube URL to
download best-quality video, subtitles (original + EN + DE), and thumbnail.
Subtitles are converted to clean Markdown. Optional audio extraction to MP3.
Supports ZIP & Send mode: downloaded files are packed into a ZIP and
delivered to the browser, with optional server-side cleanup after delivery.
An extra directory (ZIP_EXTRA_DIR) can be bundled into every ZIP.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
