Tom Mulholland cuts steaks in Malvern, Iowa. He works about 65 hours a week. He is very good at that part. He is less good, he says, at all the other jobs a grocer has to play. Meta heard him. And this week the company handed him, and every other small operator on its apps, an AI agent that can sit on Shopify, QuickBooks, Stripe, Slack, Notion, Canva and the ad accounts that already keep those shops visible. The pitch is simple. Small businesses…