feat(helpdesk): add dashboards, communication feed, settings UI and fix routing

Add support/sales/controlling dashboards with KPIs, trend charts and
risk indicators. Add debitor communication timeline, contact filters,
system recommendations engine, and configurable controlling risk rules.

Rename search→index to fix query-string preservation on back navigation.
Remove fake escalation rate metric, add KPI info tooltips, and switch
trend chart colors to red (created) / green (closed) for clarity.

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

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

@@ -7,8 +7,8 @@ $canManageSettings = !empty($helpdeskNav['can_manage_settings']);
 $helpdeskNavItems = [
     [
         'label' => t('Customers'),
-        'path' => 'helpdesk/debitor',
-        'active' => navActive('helpdesk/debitor', true),
+        'path' => 'helpdesk',
+        'active' => navActive('helpdesk', true),
         'visible' => true,
     ],
     [