docs(issue-23-24): the create skill documents --no-auto-trust, the started-based onboarding verdict and exit 43

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.agents/skills/multi-agent-mux-create/scripts/create_session.sh

@@ -17,6 +17,8 @@
 #   2  = invalid args
 #   3  = herdr session already exists (use multi-agent-mux-resume or delete first)
 #   4  = agent-sessions.yaml append failure
+#   42 = agent TUI never became ready and the process is gone
+#   43 = rollback could not kill the herdr session; it is still running (#23)
 set -euo pipefail
 
 _script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"