BEIJING — Melania Trump stayed back at the White House and didn’t join her husband for the whirlwind Beijing summit — which was documented by her director. Melania Trump is in DC and marking the 180-day milestone since the president signed the Fostering the Future Executive Order, honoring one of her signature initiatives to help foster children. Instead, director Brett Ratner is in China with President Trump. President Trump and Chinese President Xi Jinping at the Great Hall of the People in Beijing on May 14, 2026. REUTERS The Trumps with Xi and his wife, Peng Liyuan, during the president’s first term trip to China on Nov. 8, 2017. AP Ratner, who directed “MELANIA,” the first lady’s self-titled documentary, traveled on Air Force One with the president to Beijing, leading the internet to wonder why such a high-profile trip had no leading lady. “The first lady did not have prior knowledge that Mr. Ratner would be in China,” a person familiar with the trip told The Post. “The first lady only works with Mr.…