A mother and son in China spent five years making an animated film for about $200. Ten days after release it had sold fewer than 300 tickets in the entire country. This week it's rivaling Christopher Nolan's The Odyssey at the Chinese box office. Niu Lai opened August 5 with no trailer, no marketing, not even a poster. Theaters cut it from 245 screens to 4. On its worst days it earned $25. Then the clips hit social media. Viewers called it disaster-level, worse than AI, a contender for worst…