Meta Platforms Inc. unveiled a new artificial intelligence agent designed to carry out tasks on a user’s behalf, advancing Mark Zuckerberg’s vision of a future where people each have a personalized AI assistant.Called Muse, the new agent shares its name with the series of models Meta’s AI lab is developing and can help automate a variety of tasks. Meta said the tool will assist with online shopping, buying movie tickets, scheduling appointments like tennis lessons or even filling out a permissio...