For Simona Blat, the plan was to move to Europe and open a bookshop. It was early 2021, a global pandemic was still raging, and Williamsburg, her Brooklyn neighborhood of 12 years, felt like it was emptying out. Like a lot of New Yorkers during the pandemic, Ms. Blat was unemployed and seeking clarity on a hazy future. “I was going on these daily walks during the pandemic,” she said, “just to stay sane.” On one of the walks, she noticed a vintage clothing shop on Driggs Avenue had closed. The “For Rent” sign at the entrance somehow caught her…