‘Where are they now, those golden days of my youth?’ The past hangs over the characters in Pyotr Illyich Tchaikovsky’s Eugene Onegin like a veil. The folly of youth and the burning shame of costly pride are not dimmed by the passage of time, but are instead, only magnified. Early in Scottish Opera’s vibrant production there is a potent sign that the bucolic surroundings of harvest time and the budding spirit of spring love might soon be dispelled.  As Madame Larina (Alison Kettlewell} and Nurse Filipyevna (Anne-Marie Owens) reminisce about the courtships of their youth, and as the matriarch’s daughters…