The Twitter look-alike Bluesky, started by the former Twitter chief executive Jack Dorsey, is doing the impossible: making social media fun again.Then, A.I. is coming for jobs but not in the way you think.Plus: Kevin and Casey moonlight as advice columnists in a new Hard Fork segment called Hard Questions.Additional reading:Bluesky is vying to replace Twitter.IBM announced a pause in hiring, anticipating that A.I. would replace thousands of jobs at the company in the coming years.The chief executive of the education company Chegg said student interest in the chatbot ChatGPT was hurting its sales.