The gig economy isn’t just for Uber drivers and TaskRabbit furniture assemblers. San Francisco startup Wonolo — short for “work now locally” — has created an on-demand marketplace for workers to find hourly jobs in warehouses, factories, distribution centers, stores and other sites. “Staffing has been an industry that lacks innovation,” said A.J. Brustein, co-founder and chief operating officer. “It’s very targeted towards clients, not workers.