feat(helpdesk): add customer engagement analytics page [skip ci]

New "Customer analytics" page under Monitoring: surfaces who is actively in
contact vs. who has gone quiet, so the team can reach out before a customer
slips away.

- KPI tiles: total / active / no-contact / never-in-contact
- "Customers without recent contact" — longest silence first
- "Top customers by communication" — most ticket activity in the period
- Configurable no-contact threshold (helpdesk settings, default 60 days)

CustomerEngagementService aggregates the global ticket snapshot per customer
(same single-pull model as RiskRadarService — no N+1 to BC). Last contact is
the most recent ticket activity; silence beyond the threshold flags the
customer. Revenue ranking deferred (BC OData exposes no per-customer ledger).

All within modules/helpdesk/. Tests + PHPStan green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

modules/helpdesk/module.php

@@ -45,6 +45,8 @@ return [
         ['path' => 'helpdesk/team-workload-data', 'target' => 'helpdesk/team-workload-data'],
         ['path' => 'helpdesk/risk-radar', 'target' => 'helpdesk/risk-radar'],
         ['path' => 'helpdesk/risk-radar-data', 'target' => 'helpdesk/risk-radar-data'],
+        ['path' => 'helpdesk/analytics', 'target' => 'helpdesk/analytics'],
+        ['path' => 'helpdesk/analytics-data', 'target' => 'helpdesk/analytics-data'],
         ['path' => 'helpdesk/software-products', 'target' => 'helpdesk/software-products'],
         ['path' => 'helpdesk/software-products-data', 'target' => 'helpdesk/software-products-data'],
         ['path' => 'helpdesk/software-products/edit/{code}', 'target' => 'helpdesk/software-products/edit'],
@@ -138,6 +140,17 @@ return [
                 'permission' => 'helpdesk.risk-radar.view',
                 'order' => 805,
             ],
+            [
+                'key' => 'helpdesk-analytics',
+                'script' => 'modules/helpdesk/js/helpdesk-analytics.js',
+                'export' => 'initHelpdeskAnalytics',
+                'selector' => '[data-app-component="helpdesk-analytics"]',
+                'config_path' => 'components.helpdesk.analytics',
+                'default_config' => [],
+                'phase' => 'default',
+                'permission' => 'helpdesk.risk-radar.view',
+                'order' => 809,
+            ],
             [
                 'key' => 'helpdesk-settings',
                 'script' => 'modules/helpdesk/js/helpdesk-settings.js',