Hong Kong’s karate star Grace Lau Mo-sheung has struck historic gold at the World Karate Championships in Cairo, becoming the first athlete from the city to claim a world title in the sport.   The world No. 1 in women’s kata delivered a composed yet commanding performance in Sunday’s final, outscoring Japan’s Maho Ono with a total of 46.1 to 43.3 after earning higher marks from four of the seven international judges.   Lau’s victory crowns a remarkable year in which she also swept the Asian Championships in May and the World Games in August, firmly establishing herself as the world’s leading kata competitor. It also extends her dominance over long-time rival Ono, whom she has now defeated seven times this season, adding to a haul that already includes one gold, one silver and two bronze medals.