[Feature request] Better handling of disconnections in clashes

My connection is unreliable and I frequently discover that a clash actually started minutes ago, with no visible clue in my webbrowser (counter seem to work fine).

Usually, you would expect a “time out” where a client is considered disconnected when it does not answer for a while. On the client side, you would expect to have a clear “disconnected” message when synchronization with the server fails.