Preheat the oven to 400 degrees F (200 degrees C).

Spread pine nuts on a sheet pan; roast until golden and fragrant, 2 to 3 minutes. Transfer to a plate to cool.

Put potatoes and garlic on the sheet pan. Drizzle with 2 tablespoons oil and sprinkle with 1/2 teaspoon salt and 1/4 teaspoon pepper. Bake 20 minutes. Add zucchini and rosemary, toss, then continue roasting until vegetables are tender and browned, about 20 minutes. Let cool.

Squeeze roasted garlic out of its skin into a small bowl, mashing it slightly with a fork. Add remaining 2 tablespoons oil, balsamic vinegar, and remaining 1/4 teaspoon each salt and pepper; whisk to combine.

Toss roasted potatoes and zucchini in a large bowl with beans, arugula, tomatoes, and dressing. Serve in bowls sprinkled with toasted pine nuts.