There have been times when I was watching TV and wished I had access to my Joplin notes. I'd like to suggest porting to that platform if it's possible. Read-only would be all I'd hope for; typing with the remote is tedious.
Hi,
Perhaps if you subscribed to the Joplin synchronization hosting service you can pull up Joplin in a browser on your TV I have an Android TV also and I just need to test this myself I didn't think about using it this way and I don't think I will.
Regarding typing on your Android TV I use an app in the Google Play app store to give me a mouse and keyboard on my TV through my phone and it lets you type in anything anywhere in any app on your TV on your cell phone or tablet.
You must enable ADB debugging which is part of developer mode on the TV.
Here is the link to the app.
This will at least help you out a little bit.