Shop says the frame is fine. And, they had an identical derailleur hanger in stock. Yay.

'Course, after the 100+ mile round trip to get the part, and dragging the bike in and out of there without the rear wheel on and the derailleur and chain in my hand (because I couldn't see where it was any less hassle to reassemble it for rolling then take it all apart again) ... it's raining at the ride start now, and I've been riding WAY too little to want to get wet.

It's ready to go for next time, anyway.