Since the server is maintaining conversation history, should we add a conversation.resume message that includes the conversation id from a prior conversation.created message?
The client could send this to allow for reconnection to a lost connection with a prior conversation session. This could trigger the server to send a new session.resumed message that would allow the client to update the session via session.update.
Perhaps, the session.update could include a reference to a prior conversation id as a way to reconnect/use a prior chat history?