Slow-Cooker White Bean Soup With Andouille and Collards

dried white beans (such as cannellini or great northern)

andouille sausage links, halved lengthwise and sliced crosswise

large onion, chopped

stalks celery, chopped

sprigs fresh thyme

low-sodium chicken broth

bunch collard greens, stems discarded and leaves cut into bite-size pieces (about 8 cups)

red wine vinegar

kosher salt and black pepper

olive oil and bread sticks, for serving