Implement a global data flow controller for the camera -> game recording

[CmdrDats]

Currently everything kinda hangs together with add-watch data flow within paths of the atom, which is neat when you want things to be mostly decoupled and you don't really know what data you're going to be using (so you stuff everything into the global context)..

But now we do know what data we need, and what flow works, so hammer that into something a bit simpler to reason about.