Returns the next batch of article titles, the same ones the Plan Content button shows. Each title comes with its topic, format, search and day on the calendar. Defaults to a DRY RUN: nothing goes on the calendar. When the person asked to add them, call it with confirm=true. To add only some, pass their ids in keep. Set news=true for this week's news titles, the ones Plan Content's news list shows. They are written every Monday for paid workspaces with News or Trending on, and go on the calendar one a day. To plan titles about something specific, pass it as subject with the workspace topics it fits as topics. Add the ones the person wants with commit_planned_titles. If the subject fits none of the topics, offer to add a topic first (set_topics). Capped at 5/min.