The arrival of development proposals for hybrid condominium/short-term rental/hotel uses in Sarasota has left the city’s planning staff in a conundrum. That’s because the zoning code within the Downtown and Urban Mixed-Use zone districts do not contemplate that kind of mixed use. At its July 20 meeting, city planning staff members asked for, and received, instruction by the City Commission to develop a policy for the trend, which is already in p…