Keep a log of layer deletions and other significant actions
Layer operations should be logged in the session 'event logs', especially the 'delete layer' action.
The server can't log layer operations because it doesn't understand them, it's an opaque drawing command. But there isn't anything special about layer operations in the first place, if you don't want people to be able to edit a layer, remove the "general layer editing" permission or modify the layers' permissions.
Actually, I thought about this while messing with the server implementation and I got the idea that these kinds of operations could be logged on the client instead. That doesn't require the server to understand opaque messages, but would still be useful for e.g. undoing an accidental deletion or something. So I'll reopen and retitle this in that regard.
Would this issue be renamed to "Log Actions" instead with the new feature requests?