feat(helpdesk): add team workload dashboard with per-agent metrics

New standalone page (helpdesk/team) showing support agent workload
aggregated from BC tickets. KPI bar (open, unassigned, avg age, resolved),
per-agent table sorted by open tickets, period selector (30/90/180/365d).
Global OData query via getTicketsForTeam() without customer filter.
New permission helpdesk.team-workload.view with admin role assignment.
Includes 6 PHPUnit tests for buildTeamWorkloadDashboard().

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

modules/helpdesk/module.php

@@ -31,6 +31,8 @@ return [
         ['path' => 'helpdesk/debitor-communication-data', 'target' => 'helpdesk/debitor-communication-data'],
         ['path' => 'helpdesk/debitor-sales-dashboard-data', 'target' => 'helpdesk/debitor-sales-dashboard-data'],
         ['path' => 'helpdesk/debitor-controlling-dashboard-data', 'target' => 'helpdesk/debitor-controlling-dashboard-data'],
+        ['path' => 'helpdesk/team', 'target' => 'helpdesk/team'],
+        ['path' => 'helpdesk/team-workload-data', 'target' => 'helpdesk/team-workload-data'],
     ],
     'public_paths' => [],
 
@@ -71,6 +73,12 @@ return [
             'active' => true,
             'is_system' => true,
         ],
+        [
+            'key' => 'helpdesk.team-workload.view',
+            'description' => 'View helpdesk team workload dashboard',
+            'active' => true,
+            'is_system' => true,
+        ],
     ],
 
     'search_resources' => [],