BRUSSELS — Greek Prime Minister Alexis Tsipras strode into a summit of eurozone leaders with a beaming smile Tuesday, but was met with anger when it became clear he had no written proposal on how to save his country from financial ruin. With Greece's banks just days away from a potential collapse that could drag the country out of the euro, Tsipras had been expected to offer up economic reforms in exchange for loans. Instead, his government said …
