At a recent White House dinner with tech billionaires, Mark Zuckerberg sat on Donald Trump’s right side while Sam Altman watched from across the table.Their proximity to the US president was the result of careful planning by the chief executives of Meta and OpenAI, according to several Washington and company insiders. These people said the pair have sought to get closer to Trump since his relationship with Elon Musk blew up in spectacular fashion this summer.While neither men hold as much sway a...