“One Battle After Another” may be the odds-on Oscar favorite, but another nominee, for Best International Feature Film, says more about a society perpetually stressed by militarism. “It Was Just an Accident” comes from Iranian director Jafar Panahi, who channels his two terms in Tehran’s notoriously evil Evin prison into a plot about a low-key mechanic who unexpectedly comes across a man who he believes was his cruel Evin interrogator. The mecha…