Former President Donald J. Trump repeated a number of inaccurate claims that have become campaign staples in a conversation on Monday night with the billionaire Elon Musk on X, his social media platform. After describing at length the attempted assassination against him at a rally in Pennsylvania in July, Mr. Trump ran through familiar complaints about immigration — echoed by Mr. Musk — and attacks on Vice President Kamala Harris. Here’s a fact check: He inaccurately claimed that a...