An update, FWIW. An under-hood check showed nothing unplugged, so I removed the distributor cap looking for water. The lower bolt's "washer" was spinning...meaning that bolt wasn't fully tightened, but the cap and rotor were clean & unmarked on the inside. Bolted that back up and pulled each spark plug lead to see if anything looked amiss...dialectric grease still on end of plugs, so put those back in.
Wiggled the fuel injector, TPS, MAF wires, restarted car and issue gone away.
I think that's comforting...
Thanks for the suggestions.