Boeing upped its wage proposal to thousands of striking workers on Monday, offering a 30% general wage increase over four years in what it called its “best and final” offer as the strike drags on.The planemaker is also offering to reinstate a performance bonus, improve retirement and double a ratification bonus to $6,000, if the workers accept by Friday.The Seattle-area Boeing workers who build the planemaker’s strongest-selling 737 MAX jet and other planes assembled in its Washington state factories went o ...