Louise Fletcher, a late-blooming star whose riveting performance as the cruel and calculating Nurse Ratched in “One Flew Over the Cuckoo’s Nest” set a new standard for screen villains and won her an Academy Award, has died at age 88. Fletcher died in her sleep surrounded by family at her home in Montdurausse, France, her agent said. No cause was given. After putting her career on hold for years to raise her children, Fletcher was in her early 40s and little known when chosen for the role opposite Jack Nicholson in the 1975 film by director Milos Forman, who had admired her work the year before…