feat(helpdesk): refactor multi-tenant BC settings and risk radar improvements

Restructure helpdesk tenant settings into per-connection config with
improved token handling. Update risk radar data endpoint and UI.
Clean up ImageUploadTrait and update architecture contract tests.

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

modules/helpdesk/templates/aside-helpdesk-panel.phtml

@@ -22,7 +22,7 @@ $helpdeskNavItems = [
         'visible' => true,
     ],
     [
-        'label' => t('Team dashboard'),
+        'label' => t('Team workload'),
         'path' => 'helpdesk/team',
         'active' => $teamActive,
         'visible' => $canViewTeam,