China’s government is trying to reassure jittery homebuyers after a major real estate developer missed a payment on its multibillion-dollar debt, reviving fears about the industry’s shaky finances and their impact on the struggling Chinese economy. There is no indication Country Garden’s problems might spread beyond China, which seals off its financial system from global capital flows, economists say. The Country Garden episode has echoes of Evergrande Group, which is trying to restructure more than $340 billion owed to banks and bondholders.