By Katie Mansfield Former Canadian Prime Minister Brian Mulroney has died. He was 84. He forged close ties with two Republican US presidents through a sweeping free trade agreement that was once vilified but now celebrated. The country’s 18th prime minister died peacefully and surrounded by family, daughter Caroline Mulroney said in a post on X, formerly Twitter. Mulroney’s family said last summer he was improving daily after a heart procedure that followed treatment for prostate cancer in early 2023. A family spokesman said Mulroney died at a hospital in Palm Beach, Florida, where he was bein…