CLEVELAND — A woman caught on camera driving on a sidewalk to pass a Cleveland school bus that was unloading children stood in the cold Tuesday at an intersection holding a sign warning people about idiots. A Cleveland Municipal Court judge ordered 32-year-old Shena Hardin to serve the highly public sentence for one hour Tuesday and Wednesday for the Sept. 11 citation. She arrived bundled up against the 34-degree cold, puffing a cigarette and wearing head phones as passing vehicles honked. Satellite TV trucks were on hand to stream the event live near downtown Cleveland. The sign read: “Only an …