an undo option wouldn’t be good for activists, also the chat delete function will also delete the messages from the server in the future.
This is 100% user error, we can try to prevent user error but at the same time we want that the user still has full control.
Maybe we should do display an undo button for 15 seconds ala gmail? (That could work for both careless usage and “safe” deletion)
There is a confirmation dialog, we could also make it harder to accept it like type a phrase to delete it. (type chatname could be bad if you have special chars in it like emojis which increases the time you need for deletion.)
We could also think about reminding the users to make backups, in the device chat, but we should have backup encryption before we do that.