I know it isn't FOSS, but I just plug a $500 Mac mini into my LG TV and use it with a wireless backlit keyboard/trackpad combo I got for $35 off the zon. IINA is a fantastic player. I rarely use the tv os.

Not sure what exactly you are asking for, but check Jellyfin, it might be part of the answer.

Jellyfin is good. I'm currently using the Roku version

Jellyfin is great.