For more than two decades, Graham Norton has been one of the safest bets on British television. Sharp, quick-witted and effortlessly charming, the Irish presenter built an empire out of making A-listers feel relaxed enough to spill their secrets on the sofa. His BBC chat show became a Friday-night institution, surviving countless shifts in viewing habits as rivals fell away around him. When ITV announced that Norton would front a major new reality entertainment format , expectations were sky-