Audio: Listen to this story. To hear more feature stories, download the Audm app for your iPhone. Up the Estonian coast, a five-lane highway bends with the path of the sea, then breaks inland, leaving cars to follow a thin road toward the houses at the water’s edge. There is a gated community here, but it is not the usual kind. The gate is low—a picket fence—as if to prevent the dunes from riding up into the street. The entrance is blocked by a railroad-crossing arm, not so much to keep out strangers as to make sure they come with intent. Beyond the gate, there is a schoolhouse, and a few homes line a narrow drive. From Tallinn, Estonia’s capital, you arrive dazed: trees trace the highway, and the cars go fast, as if to get in front of something that no one can see. Within this gated community lives a man, his family, and one vision of the future. Taavi Kotka, who spent four years as Estonia’s chief information officer, is one of the leading public faces of a project known as e-Estonia: a coördinated governmental effort to transform the country from a state into a digital society. E-Estonia…