SAN FRANCISCO — A Silicon Valley judge began questioning potential jurors Tuesday to hear allegations that Elon Musk cheated Tesla investors by claiming in a 2018 tweet that he had lined up financing to take the electric automaker private.The tweets fueled a rally in Tesla’s stock price that abruptly ended a week later after it became apparent that Musk did not have the funding for a buyout after all. Investors then sued him, saying that Tesla shares would not have swung so widely in value if he had not dangled …