After three false starts with Pep Boys, I went to another mechanic, Gabriel of Auto Angel, who was highly recommended on this site. After a long diagnostic session and some scheduling delays, today he installed new brake rotors and pads front and rear. He seems to know what he is doing. He found nothing wrong with the suspension. For now the vibration is gone. We will see if it holds.
You had earlier referenced feeling this in the seat of the pants. That often points to a problem with the rear brakes rather than the fronts.
Glad to hear the problem is now gone.