For years, Houston produced elite football players for everybody else. They grew up here, developed here, and became stars under Friday night lights here. Then Saturday came, and too many of them left—for Austin, College Station, Baton Rouge, Norman, Tuscaloosa, and Columbus. Pick a national contender, and chances are somebody from Houston helped it win football games. The University of Houston has spent decades sitting in the middle of one of the country's richest recruiting territories while watching its best players become someone else's signing-day headline. Willie Fritz is starting to…