Kirill Serebrennikov has been confined to his home for well over a year on embezzlement charges many say are trumped-up. Zurich Opera House had engaged Serebrennikov to direct Così fan tutte two years ago and decided to go ahead, figuring that he’d be released by now. No such luck — worse, he’s not allowed to use the internet or even a telephone. Shaun Walker reports on how Serebrennikov is managing to stage the production anyway.