A new field of “tokenomics” has emerged to measure the return on all the money companies are pouring into artificial intelligence. (Nicolás Ortega/The New York Times) By LYDIA DePILLIS Corporate America was enthusiastic about artificial intelligence. Until it got the bill. Whiplash around spending on “tokens,” the units of computing power in which AI is sold, is hitting engineering teams and boardrooms. First there was “tokenmaxxing,” as executives encouraged as much AI use as possible. Then…