Bring the WebUI back

[ThinkChaos]

Since #40, the web UI was removed in favor of a Tauri app. I think having an app is great, but I'd still like to use the UI in a headless server context (I run privaxy on my router basically).
Would you be open to bringing the web UI back?

I understand you have security concerns with that (see #13), and I think the easiest solution would be to make the configuration editing app only, and the web UI be read-only. Anyways on a headless server you usually want to manage the config via files.

Besides that having separate listen address for the proxy and web UI could be nice, so it's easy to make the web UI accessible on localhost/a specific network.

Longer term. I think it's fine to allow users to do what they want with the web UI. Once you feel the app is in decent shape, you can pass the security burden on users/admins. That's what most apps do so I don't think that'd be an issue here as long as the docs say not to expose that.

Thanks for the great software, I don't route all my HTTP traffic through it yet, but it's already quite useful to me!