Well, I just did another extensive search of the garage, and I can positively, absolutely confirm -- that house has no water shut-off valve other than the one in the ground on the city side of the meter. And there is no box containing another valve in the five feet that separates the water meter from the garage.
I'm no plumber, but I was once an electrician, and I'm pretty sure there is a national plumbing code, same as there is a national electrical code. I'd bet dollars to donuts that the first item in that code is the provision that there be a way for the home owner to shut off the water in an emergency, that doesn't require a special tool. But I guess I'll reserve my lawsuit money for the day my house is ruined by water damage that could have been prevented by the missing shutoff valve.
My temporary solution was to buy a tool for the city's valve and hang it in the garage. I used it to shut off the water until next season, and I added instructions in the "welcome" book for how to shut off the water in case of a leak.
Long term, I plan to hire a plumber to install a real valve somewhere that can be operated either manually or remotely. Something like this one, which says it can detect a leak even without moisture sensors:
Amazon.com