No, Jellyfin has a server backend which manages the media and serves it up to the client frontends which support most modern operating systems like Windows, Linux and Android. See https://jellyfin.org/ for details.
I’d ditch the HTPC, and go for an Android based media player like the Shield, no moving parts, no keyboard/mouse and rarely requires an update. Had a HTPC for many years and anytime I wanted to watch something I had to mess about with it first before it would play.
Instead of Waco, Texas it will be Wacko, Texas.