Some heroes boast muscle and brawn. Others possess steely nerves and impeccable timing. But this hero is a little different. This one has feathery fur, a sunny smile, a calm nature and — for a dog — an uncanny ability to zero in on the people who need her most. She’s a 15-year-old golden retriever named Bretagne, and she’s believed to be the last surviving search dog who worked at Ground Zero in New York City after the Sept. 11, 2001 terrorist attacks.