While Bayfront Park has evolved over the years — the baseball diamond come and gone, the rise of pickleball, a dog park and kayak ramps added — one thing has remained as witness to the transformation: the recreation center.Now, and not for the first time, talk about a potential replacement of the building is beginning to buzz around the island.PastBuilt in 1970, according to property appraiser records, the 1,350-square-foot building sat at anoth…