I'm aware of no off the shelf solution, but this does sound like a problem that can be solved with electronics.

The motor controller could do electric braking if the rider's phone isn't in the vicinity of the bike. This would mean you can't push the pedals, but the wheels will still turn without resistance. If you forget to unlock it, you won't break the spokes, and there's no sudden halt, so you can still manually and safely break.

You could still run off with the bike on foot of course. But maybe if the pedals are blocked by the motor, you can use the standard lock without breaking the spokes?