feat(mux): implement onboarding prompt initialization, 4-tier UUID validation, and TUI 1:1 cross-matching

.agents/skills/multi-agent-mux-resume/scripts/update_yaml_resumed.sh

@@ -50,7 +50,7 @@ fi
 NOW_ISO=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
 
 # 새 herdr pane pid / 자식 pid 를 bash 에서 캡처 (env 로 전달, P1-B)
-PANE_PID=$(herdr list-panes -t "$SESSION_NAME" -F '#{pane_pid}' 2>/dev/null | head -1 || true)
+PANE_PID=$(_herdr list-panes -t "$SESSION_NAME" -F '#{pane_pid}' 2>/dev/null | head -1 || true)
 PANE_PID="${PANE_PID:-}"
 CHILD_PID=0
 if { [ "$AGENT" = "agy" ] || [ "$AGENT" = "hermes" ] || [ "$AGENT" = "cline" ]; } && [ -n "$PANE_PID" ]; then