Baked Salmon Mediterranean Bowl with Quinoa and Tzatziki

1 tablespoon olive oil, divided

1 tablespoon ground sumac

 ½ tablespoon cayenne pepper

½ tablespoon dried oregano

½ teaspoon salt

½ tablespoon ground black pepper

3 cloves garlic, minced, divided

1 lemon, cut in half, divided

Juice and zest from reserved ½ lemon

1 lb. salmon, or 4 (6-oz.) skinless salmon fillets

1 red bell pepper, cut into large cubes

2 zucchinis, cut into large chunks

1½ cups uncooked quinoa

6 ounce plain Greek yogurt or labneh

2 small cucumbers, one finely diced and one chopped, divided

1 tablespoon dried dill

½ cup cherry tomatoes, quartered

¼ cup kalamata olives, halved

4-6 oz. feta cheese, cut into cubes