Farmer’s Fridge, a vending machine startup selling plastic jars of fresh food like salads and wraps instead of the usual candy and soda, experienced the impact of the COVID-19 crisis in stages. First, as travel began to slow, sales dropped at its locations in airports like O’Hare and Newark. Next, as offices closed, workers abandoned its whitewashed machines in their lobbies. But at the company’s 97 hospital locations — 56 in the Midwest and 41 in the Northeast, including 24