fix(helpdesk): remove 'Ticket communication' section title entirely

Remove the heading and the CSS override — communication feed starts
directly without a title in the ticket detail view.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

modules/helpdesk/web/css/helpdesk.css

@@ -1312,9 +1312,6 @@
     max-height: none;
   }
 
-  .helpdesk-ticket-detail-content .helpdesk-support-section-title::after {
-    display: none;
-  }
 
   /* --- Controlling dashboard --- */