I went down this rabbit hole about a year ago, and didn’t have much luck. In the end, the best results I was able to get were from Steam’s Big Picture Mode on a Windows device, mostly launching Firefox (might have been Chrome?) with different launch arguments to immitate a smart TV.

Most available software either doesn’t support Linux well, or doesn’t support non-kb&m input methods. You could try SteamOS, now that its out, but unfortunately my hopes wouldn’t be high for it.