With two weeks to go before a scheduled trial, “It Ends With Us” co-stars Blake Lively and Justin Baldoni announced a surprise settlement Monday, ending a dispute that had played out in court hearings and headlines for almost a year and a half. Publicly, lawyers for the former co-stars continued to hash out key pretrial issues before a federal judge. But behind the scenes, talks to resolve the case began in earnest last month, after a judge dismissed most of Lively’s claims , a source familiar with the matter told NBC News. The teams held meetings over the weekend and finalized the deal Monday, the source said. Terms of the settlement were not disclosed. By Monday evening, after attorneys for Lively and Baldoni issued a joint statement , Lively stepped out in full glam for the Met Gala , where she smiled and waved to fans as she made her way up the steps of the Metropolitan Museum of Art in New York City.…