Closes an open browser session. For: a finished task the user does not want to reuse, or an abandoned session. An open cloud browser keeps consuming execution time until it is closed. Unsaved work is kept: a session with defined functions, or a recording that did more than visit pages, is auto-saved as a workflow first (the reply names it; an inactive draft when it would not replay). discard=true closes without keeping anything. A session bound to a build is settled by that auto-save, or marked cancelled.