Since its launch in March 2015, Bezar.com, the online marketplace from Bradford Shellhammer (founder and former head of Fab.com), has become a vibrant and vital design resource for 180,000 subscribers and counting. Until last week, the site was the host solely of highly curated, invite-only, three-day-long sales of modern art, furnishings, accessories, and jewelry. Art and home currently comprise 75 percent of the site’s business. And now comes phase two: Storefronts, a permanent design resource, featuring 5,000 items from 100 brands…