fix: add missing data() extension to email-templates.js

The emailTemplatesPage() Alpine.js component was missing the ...data()
extension from init-alpine.js, causing JavaScript errors. Added the
base layout inheritance and currentPage for proper navigation state.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/modules/messaging/static/admin/js/email-templates.js

@@ -12,6 +12,12 @@ const emailTemplatesLog = window.LogConfig?.createLogger?.('emailTemplates') ||
 
 function emailTemplatesPage() {
     return {
+        // Inherit base layout functionality from init-alpine.js
+        ...data(),
+
+        // Set current page for navigation
+        currentPage: 'email-templates',
+
         // Data
         loading: true,
         templates: [],