The menswear brand Kiton opened the doors to its new San Francisco store this month, a preliminary step in the Italian company’s plan to expand globally over the next several years. Situated just one block from Union Square on the corner of Post Street and Grant Avenue, the 2,500-square-foot boutique is housed in the 110-year-old Shreve Building—named after its longtime principal tenant, Shreve & Co. jewelers—which survived the great 1906 earthquake. The new store will offer the 59-year-old brand’s renowne…