At the start of the new documentary “Brunello: The Gracious Visionary,” Brunello Cucinelli strolls through his vineyards at night, illuminated by dozens of small, contained fires that protect the vines from frost. He’s a man in his 70s, walking with ease and confidence through his domain — a world he spent decades crafting, curating and restoring. Last Tuesday, the fashion designer strolled in a very different location. He walked down the star-studded red carpet, flanked by his family, at the