Minneapolis is one of those cities with a bad habit of bulldozing old buildings every few decades and starting over architecturally. So it was a big deal last year when the city mounted a major overhaul of a long-vacant architectural icon in its urban core. The old Sears/Roebuck store in the city’s Midtown district has been transformed into a global food marketplace and residential tower, and in the process, it has brought Minneapolis into a world where architecture can be used not only to draw oohs and aahs from tourists (as several other recent high-profile projects in the city were clearly intended) but to revitalize a moribund sector of the city and preserve an icon of a bygone era.