fix(helpdesk): add empty ticketNo field to GetTicketFile SOAP envelope

BC expects all four parameters in the envelope even if ticketNo is
empty. The entry number alone should be sufficient to identify the file.

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

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

@@ -345,11 +345,14 @@ XML;
     {
         $escapedContactNo = htmlspecialchars($contactNo, ENT_XML1 | ENT_QUOTES, 'UTF-8');
 
+        // BC signature: GetTicketFile(TicketNo, EntryNo, ContactNo, ICISupportFilePort)
+        // The old monolith omitted ticketNo — BC resolves it from EntryNo.
         return <<<XML
 <?xml version="1.0" encoding="utf-8"?>
 <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:urn="urn:microsoft-dynamics-schemas/codeunit/ICISupportWebserviceAPI">
   <soap:Body>
     <urn:GetTicketFile>
+      <urn:ticketNo></urn:ticketNo>
       <urn:entryNo>{$entryNo}</urn:entryNo>
       <urn:contactNo>{$escapedContactNo}</urn:contactNo>
       <urn:iCISupportFilePort></urn:iCISupportFilePort>