fix(helpdesk): remove title line in team widgets, fix table columns and debitor links

- Hide section-title ::after line inside team widgets
- Fixed table-layout with consistent column widths (12/25/43/20%)
- Debitor link uses customer_no (route param), displays customer_name
- Add Customer_No to OData select for debitor link resolution
- Add customer_no to open_ticket_details backend structure

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

modules/helpdesk/lib/Module/Helpdesk/Service/DebitorDetailService.php

@@ -1662,6 +1662,7 @@ class DebitorDetailService
                     'age_hours' => $ageHours,
                     'critical' => $isCritical,
                     'customer_name' => trim((string) ($ticket['Company_Contact_Name'] ?? '')),
+                    'customer_no' => trim((string) ($ticket['Customer_No'] ?? '')),
                     'last_activity' => $lastActivityDisplay,
                 ];
             }