Yeah, I am going to introduce some refactorings that should kill appstate once and for all.  Much of what is contained in it will be moved to ``type prometheus struct {}``, but the whole ``p prometheus`` bundle won't be passed around into the entire program—only the parts that are required.

Some of these refactorings will shift the construction of dependencies into the realm of ``func main() {}``, where lifecycle events can be better connected.