I'm Not the Protagonist Goldfinger

Su Qingshi traveled through time. (Vest + system + time travel + no cp) Traveling to an era of steam, where races were mixed and managed by the federation, she was not dressed as a nobleman who had no worries about food and drink, nor even a commoner. She was dressed as a thief, the kind of thief who was squeezed out of all his value, had a high fever, and was abandoned in the slums while dying. When she was desperate, a pair of hands rescued her... A few years later, late one night, a group of people chased a sickly young man into an alley, and the gears of fate began to turn... "System, you said he is the protagonist? Did I travel into a book? Then what am I? Villain? Cannon fodder? Supporting actress?"