CRADLING the glittering silver trophy on a sunny summer’s day on Centre Court, Peng Shuai basked in her moment of triumph. The Chinese tennis superstar was a women’s doubles winner at Wimbledon and garlanded by a 1.4 billion-strong population back home as a national treasure. And as the world top-ranked doubles player and the women’s singles No 14, she had the world at her feet while counting the game’s elite among her network of close friends. But eight years later, the popular and established 35-year-old star of the women’s game has vanished — and has failed to return calls from…