simplified "go back" functionality

backend/src/services/tour_pages.js

@@ -313,15 +313,10 @@ class TourPagesService extends BaseService {
       }
     }
 
-    // If this page has a history-mode back button, trigger regeneration of
-    // other pages' forward elements that are missing reversed videos.
-    // This runs every save but only processes elements without reverseVideoUrl.
-    if (thisPageHasHistoryMode && projectId && !options._skipHistoryModeCheck) {
-      logger.info(
-        { projectId },
-        'History mode back button detected - scheduling forward regeneration',
-      );
-
+    // Always check all project pages for missing reversed videos on any page save.
+    // Uses async queue to avoid blocking the save response.
+    // Elements that already have reverseVideoUrl are skipped (no duplicate work).
+    if (projectId && !options._skipHistoryModeCheck) {
       TourPagesService.enqueueProjectReversedVideosRegeneration(
         projectId,
         currentUser,