Require confirmation and block deleting library actions still referenced by node groups.

service/internal/api/actions_handlers.go

@@ -49,6 +49,7 @@ var (
 	errActionIDRequired       = errors.New("action id is required")
 	errActionWidgetTypeNeeded = errors.New("widget_type is required when show_widget is true")
 	errActionWidgetTypeBad    = errors.New("widget_type must be memory, disk, or raw")
+	errActionInUse            = errors.New("action is used by node action groups; remove or clone to customize first")
 )
 
 func actionsGetHandler(configDir string) http.HandlerFunc {
@@ -221,6 +222,16 @@ func actionsDeleteHandler(configDir string) http.HandlerFunc {
 			return
 		}
 
+		groups, err := settings.LoadNodeActionGroupsOrEmpty(configDir)
+		if err != nil {
+			writeJSON(writer, http.StatusInternalServerError, apiErrorResponse{Error: err.Error()})
+			return
+		}
+		if settings.LibraryActionInUse(groups, actionID) {
+			writeJSON(writer, http.StatusConflict, apiErrorResponse{Error: errActionInUse.Error()})
+			return
+		}
+
 		store.Actions = append(store.Actions[:index], store.Actions[index+1:]...)
 		if err := settings.SaveActions(configDir, store); err != nil {
 			writeJSON(writer, http.StatusInternalServerError, apiErrorResponse{Error: err.Error()})