Implement low-level roughing loop monitoring

The BEE controls the gatevalve directly. While it is open, the BEE needs to pay attention to the state of the vacuum line; specifically the turbo and the rough-side pressure.

I propose to have the roughActor continuously (0.25s? 0.1s?) broadcast pressure, and for the BEE to shut the gatevalve if pressure goes high or no pressure keyword is received quickly enough.