Have you looked at soulseek/slskd (docker soulseek client intended to be used with the *arr stack)?

There’s one about dick jousting too.

I hope the common abbreviation becomes ‘Top-fighting Yuri’ (as a play on cock-fighting ofc)

Actually, I double checked, it’s only on the login page

I thought there was a HTML section too, but couldn’t check at work.

I’m too noob to do so, but jellyfin does have the option to add HTML/CSS elements, so it definitely should be possible.

https://jellyfin.org/docs/general/clients/css-customization/