Artificial-intelligence agents can already help book your air travel, debug your software and plan your workout routines. Soon, they might serve as your stockbroker, too. Public, a privately held brokerage firm, is rolling out a feature allowing customers to use AI to automate their investing tactics and execute trades. AI agents could be deployed to buy protective puts should oil spike, hedging against potential stock losses, and automatically sweep customers’ cash into higher-yielding assets, like bonds. Account holders could also use the agents to add a 20% stop-loss order on their trades, limiting potential losses by automatically selling a security…