Reports that Bridgeport, Conn., filed bankruptcy papers that amounted to an urban manifesto of grievance against the federal and state governments, accusing them of leaving economically depressed and racially isolated cities to struggle alone with costly social problems. (Related articles on page 26: Guide to the future, an analysis of fiscal problems in other cities, by S. Bartlett; For Mayor Moran, Bridgeport's revival proves elusive, by D. Hevesi.)