I could totally wrong, but my assumption is that you’d get a small dedicated box (mini PC) that has an display port/hdmi/lightning port and usb ports and plug that into your TV like you would an Apple TV.
A remote control with wifi would work pretty easily by being connected into usb port, just like a wireless mouse.
Something like an ASUS NUC comes to mind for me but it’s designed to work with anything that you can install Linux on. https://www.ebay.com/sch/i.html?_nkw=asus+nuc&_trksid=p46248...
Ok. That makes sense.
I wonder if you can then use Netflix and other streaming services? I have a Chromecast device and could probably just switch the HDMI to use that. I can use Netflix on my Linux laptop but I haven't tried Disney and I would very much doubt Apple+ would work on KDE.