WASHINGTON — The global economy is holding up better than expected despite major shocks such as President Donald Trump’s tariffs, but the head of the International Monetary Fund says that resilience may not last.“Buckle up,” Managing Director Kristalina Georgieva said in a speech at a think tank Wednesday. “Uncertainty is the new normal and it is here to stay.”Her comments at the Milken Institute come on a day when gold prices hit $4,000 an ounce for the first time as investors seek safe haven from a weaker ...