It's official: Martha Stewart is a saint. Over at the Sirius Radio headquarters in Manhattan, she "personally reworked" a holiday tree in the lobby, a staffer claims. "She really got into it, she put on tons of lights, ornaments and hung Howard Stern and Martha cookies," the source squeals. "It's an unbelievable tree, we don't even remember the one before... It was drab and ugly, and they didn't invest a lot of time in it. Martha saved Christmas." Is there anything she can't do? [Page Six]