Before the tractors showed up, Raimondi Park didn’t look like the future home of a professional baseball team. Sitting in the shadow of Interstate 880, the long-standing West Oakland field felt forgotten. Almost every patch of grass was overgrown and the infield dirt had long since been blanketed with a thin layer of sod in a lighter shade of green. The pitcher’s mound, not much more than a bump, had become the territory of large Canadian geese that were seemingly…