Snapper with Blistered Bean Salad and Chile Vinegar

Name: Snapper with Blistered Bean Salad and Chile Vinegar
Ingredients: 1 habanero chile, seeds removed, finely chopped; 1 small garlic clove, finely chopped; ½ cup unseasoned rice vinegar; 4½ teaspoons light brown sugar; Kosher salt; 2 small red onions, cut through root ends into 8 wedges; 2 cups sugar snap peas, strings removed; 2 tablespoons olive oil, divided, plus more for drizzling; 1 pound green beans, trimmed; 4 6-ounce snapper fillets; 1 cup torn basil leaves; ¼ cup crushed salted, dry-roasted peanuts