Afghan war vet MJ Hegar tiptoes through a political minefield — The 3.5-minute video that tells the life story of Mary Jennings Hegar shifts seamlessly from suburban dining room to Afghan battlefield to the halls of Congress. The Steadicam cinematography carries echoes of Goodfellas (though its director, Cayce McCabe, actually had the single-shot aesthetic of Oscar winner Birdman in mind), and…