New rule in CLAUDE.md

It's a new bullet that goes right after the rule about how the owner works (requirements, demos and artifacts, code in the background):

  opened, never shown up front.
+ - Obeya's UI never sends the owner to the command line: when a message suggests a step (pushing
+   `main` first, say), Obeya offers it as an action right there, or the message doesn't mention it.