Luigi Mangione could be just hours away from a stunning legal turn — pleading guilty to federal stalking charges stemming from the killing of UnitedHealthcare C

Luigi Mangione could be just hours away from a stunning legal turn — pleading guilty to federal stalking charges stemming from the killing of UnitedHealthcare CEO Brian Thompson. But there could still be a last-minute twist: Mangione can change his mind at any point — even during today’s hearing. W…