feat: update search to use repetition.delta field instead of event.payload

- Add search in repetition.delta field (JSON string format)
- Keep fallback to event.payload fields for backward compatibility
- Search now looks in repetition.delta as primary source since payload data moved to repetitions collection

Author: pavelzotikov

src/models/eventsFactory.js

@@ -292,6 +292,12 @@ class EventsFactory extends Factory {
     const searchFilter = search.trim().length > 0
       ? {
         $or: [
+          {
+            'repetition.delta': {
+              $regex: escapedSearch,
+              $options: 'i',
+            },
+          },
           {
             'event.payload.title': {
               $regex: escapedSearch,