Kate Landau is officially back. The silver medalist at the 1996 NCAA championships in the 10K was 19th in the elite 10,000 at last weekend’s Portland Track Festival. Her age isn’t noted, but her splits were — and a finishing time of 3:44:46.01. She’s 41. That means she shatters the listed W40 American record of 34:58.54 by Madelyn Noe-Schlentz in 2002. (The listed WR is 31:33.44 by Rio Olympian Jo Pavey of Great Britain, but Kenya’s Edith Masai ran 31:31.18 in 2007.) Kate’s historic run comes after a rollercoaster career that saw her fighting an eating disorder — anorexia —…