A page turns. This summer, Valdo Riva, owner of the Café Max in Paris, retired and sold the restaurant he acquired 18 years ago after a breakup. The premises have been taken over by Corfou, a gastronomy investment firm owned by chef Frédéric Vardon, owner of the 39V, on the city's Avenue Georges V, and friend of famous French chef and businessman Alain Ducasse. With Riva no longer at the helm, there is uncertainty over whether Café Max's long-standing clientele of senior security chiefs and film