Customizable 404 page

[camelgod]

Is your feature request related to a problem? Please describe.
When entering an invalid URL, you just get a plain text reticulum "Invalid URL".

It is essential for my users to get clear information and steps to solve their flow when encountering a broken link.

Describe the solution you'd like
Reticulum reverse proxy into a 404 page that is customisable by custom client devs such as a 404.html.

Describe alternatives you've considered
Cant think of any good alternatives as Reticulum is the one handling the redirection, which is hard to customise.