There's a manual way to run the UI locally for now: https://app.radicle.xyz/nodes/ash.radicle.garden/rad:z4V1sjr...
We'll be also working on packaging the js bundle so that it can be distributed and served locally without setting up a dev environment in the future.
One interesting thing you can do is you can actually point the hosted web interface to your local node, as long as you're running rad-httpd.
https://app.radicle.xyz/nodes/127.0.0.1:8080/rad:z3gqcJUoA1n...
I know that there is also a web-frontend (kinda like GitHub) for radicle: https://app.radicle.xyz/nodes/seed.radicle.xyz/rad:z3gqcJUoA.... But I haven't seen a guide how to set that web frontend up locally.