fix(helpdesk): rename Performance tab to Historical

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

modules/helpdesk/i18n/default_de.json

@@ -298,5 +298,6 @@
   "No team data available.": "Keine Team-Daten verfügbar.",
   "Current": "Aktuell",
   "Performance": "Leistung",
+  "Historical": "Historisch",
   "Queue": "Warteschlange"
 }

modules/helpdesk/i18n/default_en.json

@@ -298,5 +298,6 @@
   "No team data available.": "No team data available.",
   "Current": "Current",
   "Performance": "Performance",
+  "Historical": "Historical",
   "Queue": "Queue"
 }

modules/helpdesk/pages/helpdesk/team/index(default).phtml

@@ -68,7 +68,7 @@ $periodLabels = [
         <div class="app-tabs" data-tabs data-app-component="tabs" data-tabs-param="tab" data-tabs-storage-key="helpdesk-team-tabs-v1">
           <div class="app-tabs-nav">
             <button type="button" data-tab="current" data-tab-default><?php e(t('Current')); ?></button>
-            <button type="button" data-tab="performance"><?php e(t('Performance')); ?></button>
+            <button type="button" data-tab="performance"><?php e(t('Historical')); ?></button>
           </div>
 
           <div data-tab-panel="current">