Adding a mechanical part to a lock insert
The "knob" cylinder shown in your picture is probably as close to ideal as you are going to get. Just modify the knob so you can attach your motor, directly or via drive belt or whatever.

It sounds like a better solution would be to either install a guard over the keyway so the kids can't tamper with it, or to switch to a keyless system so the problem can't varied in the first place.

I presume the apartment does not have a second door so you can't just go around that way.