Add compatibility with octo-fiesta to download tracks

[Leiasticot]

Hello,

First of all, thanks for your work.
I have a feature request regarding automation with octo-fiesta (a Subsonic API proxy).

The Goal : I would like to know if it's possible for Explo to automatically trigger the download of tracks once a playlist is generated using octo-fiesta.

Technical feasibility : since Octo-Fiesta acts as a standard Subsonic server, it performs "on-the-fly" downloads from providers (like Deezer or Qobuz) whenever a client requests a file, so theoretically, Explo would just need to : generate the playlist as usual, iterate through the track IDs, send a standard Subsonic /rest/download (or /rest/stream) request for each title and artist. By doing this, Octo-Fiesta would intercept the request and automatically fetch the file in FLAC (depending on server config) and cache it. This would allow a complete "Generate & Collect" workflow without needing a separate player to trigger the caching.

Thanks for considering this !