I have confidence the shop can fix it, it's a good shop, and I'm suspecting that as this is a new bike it's time for its routine 500 mile checkup for cable adjustments, etc. Actually a little short of 500 miles, but I'm not waiting!
One of the other riders in our small group had a plastic gadget mounted on the bottom of her seat tube specifically designed to stop this kind of mishap -- sort of like a rear dork disk in concept, but very unobtrusive. I don't know what it's called, but I'm curious whether anyone's familiar with it -- I'm interested in trying because I admit I'm a little skittish at this point about uphill shifting on the front chainring.