Little progress update on the weekend's developments.
I've finished the friends list and private room portions of the chat server now, and also integrated that into the RTB database. The things left to do are authentication (leaving this until last because I'm developing locally, but it won't take long at all), sorting friends into groups, and messaging which is also relatively simple. Fun bits then include some security and secret management commands and then I'm going to profile and load test it and see where we stand after that.
Then we move onto the chat client which is a bit harder. The friends list part of the interface is complete and just requires a few small changes to get it working with the new server, then there's just the messaging interface which shouldn't be too hard. As you can see from the screenshots, a bunch of the work chat client is already done.