An ice-skating rink made its debut last weekend on the rooftop terrace of the Canopy Hotel at Pike & Rose. The rink, which features synthetic ice, is open for the rest of this month with lounge seating on one side and a hotel menu on the other. Tickets are $14 to $17 per person and benefit the nonprofit Mel’s Rink Foundation, which is raising money to build an indoor sports facility for kids with special needs.