For leaves with NO sticks, the "line trimmer style" leaf shredders are quite effective and tolerate rocks, etc with minimum excitement.
A paper shredder style blade would need an ENORMOUS amount of force to deal with a 1/2" stick in the unfortunate orientation (across the throat), and one will surely get turned that way and jam it. Plus, I'm not aware of anyone making one that isn't a paper shredder.
I've seen at least one "first world dreamer's idea of something for third world" that tried to use a sort of coarse concrete grinding stone for more or less this job, but it was sensitive to moisture content and hard to feed, to the extent that they were willing to admit "reality issues" - I cannot seem to relocate the site right now.
A hammermill should do the job on the not-low-cost end of the spectrum, and abusing/adapting an old lawnmower is a traditional approach on the low-cost end of the spectrum. If you could lay hands on one a flail mower would be ideal, but the vast majority of those are tractor-sized units.
My actual solution for the time being is to pile them, and add manure if I want to hurry the process along, though that is a relative use of "hurry." I have also contemplated (but not implemented) turning them to charcoal.