The expression “Renaissance woman” is an overused one — often deployed in reference to anyone who might have a toe in more than one subject area. But when it came to Samella Lewis, it was true. Lewis was an artist, an activist, a historian, an author, a curator, a professor, a gallerist, a collector and a beloved mentor who helped document and elevate work by Black artists for almost eight decades. A down-to-earth yet steely woman who helped integrate Black artists into the American canon, Lewis died of renal failure on Friday at a hospice in Torrance. She was 99. The death was confirmed by her younger son, Claude Lewis.…