In a city where filthy sidewalks are many residents’ No. 1 complaint, City Hall has come up with a new way to deal with No. 2. It sounds like silly elementary school banter, but it’s real. San Francisco is about to launch the Poop Patrol. In about a month, a team of five Public Works staffers will begin patrolling the alleys around Polk Street and other hot spots in a vehicle equipped with a steam cleaner. They’ll begin their shifts in the afternoon, as the city starts losing its sheen from overnight cleaning. The Poop Patrol’s mission? To spot and clean piles of feces before anybody complains about them.