Something like Browsh? It still uses firefox underneath the hood though

You mean a web browser in a terminal?

OpenBSD actually, but close

because we all know that routers have so much RAM that installing DNS, NTP, mounts, session, log management isn’t a problem? something doesn’t add up…

freewear.org

Ruby on Rails?

No one is going to develop exploits only for a browser with certain default security options disabled (especially these made at compile time using toolchain). Binary exploitation is hard, and extremely not worth the effort in this case.