Frances White was treated like a superstar yesterday, even if she didn’t get to sing with one. White, a Mechanicsville resident, was one of four finalists chosen to appear live on the “Today” show for the “Sing in the Spotlight with Jennifer Hudson” contest produced by the NBC morning program. But the longtime gospel singer was bested by 19-year-old Melissa Goscinski from Queens, N.Y., who got to share the stage with Hudson as her prize.