Two and one-half stars. Rated R. 115 minutes. “The Florida Project,” Sean Baker’s exuberant, ungovernable ode to the innocence and resilience of childhood, takes place in a ramshackle lavender-painted hotel called the Magic Castle, hard by Orlando’s Disney World. Along with its neighboring oxymoronically named fleabags, the Magic Castle evokes the American Dream, while denying it at every downbeat, threadbare turn.