Scheduler: native recurrence handling, onActionCompleted persistence, EXDATE RFC5545, UI icon cleanup

server/routes/events.py

@@ -68,14 +68,15 @@ def get_events():
             for ex in all_exceptions:
                 if ex.is_skipped:
                     exd = ex.exception_date
-                    # Create the EXDATE timestamp using the master event's original start time
-                    # This should match the time when the original occurrence would have happened
+                    # Create the EXDATE timestamp in Syncfusion's expected format
+                    # Use the exact time of the occurrence that would have happened
                     occ_dt = datetime(
                         exd.year, exd.month, exd.day,
                         base_start.hour, base_start.minute, base_start.second,
                         tzinfo=UTC
                     )
-                    token = occ_dt.strftime('%Y-%m-%dT%H:%M:%SZ')
+                    # Format as compact ISO without separators (yyyyMMddThhmmssZ) - RFC 5545 format
+                    token = occ_dt.strftime('%Y%m%dT%H%M%SZ')
                     tokens.append(token)
             if tokens:
                 recurrence_exception = ','.join(tokens)