Construction began Friday on a Navy ship named after Harvey Milk, a former San Francisco supervisor and activist who was fatally shot months after becoming the first openly gay man elected in California more than forty years ago. Almost 30 years before his election, Milk was a Naval dive officer based in San Diego. His nephew, Stuart Milk, attended Friday’s event and said naming the ship — known as a fleet oiler — after his uncle sends a message to people around the world.