(Photo: Marc Brenner) The world of spies, subterfuge, and assassination has long been grist to the operatic mill. Scarpia runs the secret police in “Tosca”; Paolo poisons Boccanegra in Verdi’s Venetian drama of political intrigue; Leonora infiltrates a prison disguised as a man in “Fidelio”. So a contemporary tale like that of dissident and former KGB agent Alexander Litvinenko, poisoned {…}