Pork Meatballs and Cucumber Salad

Name: Pork Meatballs and Cucumber Salad
Ingredients: ¼ cup golden raisins; 2 lb. thin-skinned cucumbers (such as Persian, English hothouse, and/or kirby) cut into bite-size pieces; 2½ tsp. kosher salt, divided, plus more; 3 Tbsp. extra-virgin olive oil, divided; 3 Tbsp. pine nuts; ¾ cup Castelvetrano olives, pitted, divided; 1 large egg; 2 garlic cloves, finely grated; ½ cup panko (Japanese breadcrumbs); 3 Tbsp. finely chopped parsley; ¼ tsp. crushed red pepper flakes, plus more for serving; Freshly ground black pepper; 1 lb. ground pork; ½ small red onion, very thinly sliced (use a mandoline if you have one); 2 cups tender herb leaves (such as mint and/or parsley); 1 Tbsp. red wine vinegar; Plain whole-milk Greek yogurt (for serving)