fix: suppress "event updated" notifications for permission-only changes

Changing editPermission on a shared event no longer triggers a generic
"updated" sync notification. Real edits (title, date, notes, location)
still notify normally.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/bare.js

@@ -1049,6 +1049,10 @@ async function notifySyncChange ({ op, value, key, prev, updatedByName, updatedB
           title = who + ' updated location for ' + what
           body  = value.location
 
+        } else if (prev.editPermission !== value.editPermission) {
+          // Permission-only change — no notification needed
+          return
+
         } else {
           title = who + ' updated ' + what
           body  = value.date ? formatDate(value.date) : ''