gosanlin/nofufaudio — reverse-engineered prompt

Build me a desktop music app for Windows and Linux that feels like a clean all in one player for YouTube, Spotify playlists, and my local audio files. I want to be able to paste a YouTube video or playlist link and add it to my library, import a Spotify playlist by URL and have it match the songs to playable audio, and also load folders of MP3, FLAC, WAV, OGG, M4A and similar files with cover art and metadata picked up automatically.

Make it good for everyday listening, with a real library view, favorites, custom playlists, recent plays, search, a persistent queue, shuffle, repeat, crossfade, volume leveling, and media key support. I also want downloads for single songs or full playlists with progress shown, plus an equalizer, simple nightcore and slowed style controls, a fullscreen visualizer, synced lyrics when available, and theme customization with export and import. Tray behavior and a polished desktop feel matter too. Look up current docs online if you need to.