Salesforce and Nvidia have built Koa, a reasoning model trained for sales and customer support, and it will sit inside Agentforce next to the models Salesforce already pays for. Until now, when an Agentforce agent hit a long or multi-step reasoning task, Salesforce's AI gateway routed the prompt out to a frontier model — Claude or ChatGPT. Koa is the in-house answer to that, and the pitch is…