Skip Mail calendar sync for Meet rooms created by Ladill Events.

Events owns calendar entries for events-sourced rooms so virtual sessions
do not duplicate on the webmail calendar.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Models/Room.php

@@ -200,6 +200,11 @@ class Room extends Model
         return \App\Support\EventsSourceLink::isLinked($this);
     }
 
+    public function isEventsSourced(): bool
+    {
+        return (($this->source ?? [])['app'] ?? '') === 'events';
+    }
+
     public function hasEventsRegistrationInvite(?string $email): bool
     {
         if ($email === null || trim($email) === '') {