Mahsa Amini, 22, traveled from her hometown in the province of Kurdistan to the Iranian capital, Tehran, this month. Emerging from the subway, she was arrested for failing to cover her hair modestly enough. Three days later, she was dead. The anger over Ms. Amini’s death has prompted days of rage, exhilaration and street battles across Iran, with women stripping off their head scarves — and even burning them — in the most significant outpouring of dissent against the ruling system in more than a decade. Guest: Farnaz Fassihi, a reporter for The New York Times.