Are you aware of Audiobookshelf[1][2]? While Cardo is a very cool initiative, I wonder if considered joining forces with Audiobookshelf as it might save up some duplicated efforts :)
[1] https://www.audiobookshelf.org/showcase#:~:text=Podcast%20li...
audiobookshelf looks more like a media server for mostly audiobooks, a la plex or jellyfin -- + podcasts as an extra thing
whereas cardo seems to be a standalone desktop app just for podcasts
not really in the same category