It’s a killer birthday gift. The legal defense fund for Luigi Mangione reached more than $1 million in donations Tuesday, with droves of starry-eyed supporters pitching in to help the alleged UnitedHealthcare CEO assassin on his 27th birthday. “Happy 27th Birthday to the man, the myth, the legend. You are so loved. May you stay healthy and strong and keep the fighting spirit inside you,” one anonymous fan wrote while donating $27 on Mangione’s birthday. “This is my 7th donation, and I will keep donating as long as I need to. You are fighting for your life, but know there...