Brake lights
#1
#2
No there are no sensors for the brake lights. It sounds like maybe the tech that did the brake job unplugged the brake light switch for some reason. The switch is up at the top of the brake pedal arm, attached to the steering column brace. I would check there first then check the 2 wire harness plugs under the back end of the bed to be sure the tech didn't unplug it there. That is pretty unlikely though.
If the switch and the light harnesses are plugged in but you still have no brake lights, it is possible you just have a bad brake light switch that coincidentally failed when the brake job was done. Or it may have failed before then and you may not have been aware the brake lights were not working. If they worked before the brake job and you don't feel like checking it yourself, maybe you could take it back to the shop that did the brake job. There should be some kind of warranty period for their work.
Jimmy
If the switch and the light harnesses are plugged in but you still have no brake lights, it is possible you just have a bad brake light switch that coincidentally failed when the brake job was done. Or it may have failed before then and you may not have been aware the brake lights were not working. If they worked before the brake job and you don't feel like checking it yourself, maybe you could take it back to the shop that did the brake job. There should be some kind of warranty period for their work.
Jimmy