Everyone loves a good last-ditch reinvention. Actor Robert Downey Jr. was uninsurable and nearly washed out of Hollywood before "Iron Man" revived his career. Tennis player Andre Agassi looked finished before he shaved his head, embraced his grit, and returned to world No. 1. But business reinventions are uniquely enthralling. We don't have to wait years to see if the gambits will pay off. We have stock prices to provide real-time feedback. On Wednesday, direct-to-consumer shoe retailer