Early December brought frosty temperatures to New York and cooled down Manhattan’s luxury contract signings. Deals dropped to 34 contracts signed for homes asking $4 million or more in the borough between November 29 and December 5 — the lowest in nine weeks — according to Olshan Realty’s weekly report. The total sales volume was just under $265 million with buyers agreeing to purchase 24 condo units (13 sold by developers), eight co-op units and