A plan to transform a gritty, industrial stretch of South End waterfront into a glassy headquarters for the world’s largest hedge fund came into sharper focus this week, following submission of zoning applications from developer Building and Land Technology. In addition to a five-story, 850,000-square-foot office, the campus for Bridgewater Associates calls for a helipad, a floating recreational barge, a restored estuary and a marina…The heart of the plan is a giant office complex designed by Cutler Anderson Architects. The Washington-based firm previously designed Bill Gates’ private home in Medina, Wash. Made up of two long, curved buildings joined in the center by bridges and paths, the structure is poised to become the most striking presence on the Stamford coastline. The project’s goal, according to the coastal site plan application, is “to house a corporation in an environment that fosters personal interaction and a strong connection to the living world.” [Stamford Advocate, earlier]