Feature: give an error when the websocket uri is not accessible

[macau23]

Related to

Web-Frontend (what users interact with)

Impact

better user experience

Missing Feature

If the reverse proxy is misconfigured and /ws/ is not working (e.g. missing port 3000), an error in the gui would be nice.
Currently semaphore appears to be working but does not because of lack of feedback (but actually is working if you refresh)

Implementation

Show an error in the gui

Design

No response