Margarita Chavez has the best house on the block. At least, that’s how she describes it to all who come to visit her in Detroit Park. She wants all of her neighbors to feel that same pride in their home. So Chavez patrols nearby streets to report neighborhood ills; trash, stray dogs and overgrown lawns. She’s a familiar voice to the city’s 311 operators — a squeaky wheel who knows how to get things done, for herself and her neighbors.