In a surprise reversal of its previous decisions, the Board of Supervisors voted unanimously on Tuesday to support an appeal to delay a major, 157-unit Mission District housing project on South Van Ness Avenue near 26th Street. The project must wait for the city to conduct further study, though it’s unclear whether the project would go forward as envisioned or not. The appeal was led by Scott Weaver, a tenant attorney and San Francisco Tenants Union volunteer.