On the eve of Donald Trump’s inauguration, CBS sitcom “The Big Bang Theory” shared a hidden message that was a not-so-thinly veiled warning about the incoming president. A vanity card from co-creator Chuck Lorre that flashed on the screen at the end of Thursday night’s episode contained the lyrics to George Harrison’s song, “Beware of Darkness.” Watch out now, take care, Beware of greedy leaders They’ll take you where you should not go While Weeping Atlas Cedars They just want to grow, grow and growBeware of darkness The vanity card, which also ran at the end of the CBS show “Mom,” did not mention the president-elect by name.