Add ticket system with QR scanner and PDF generation

- Add ticket validation and check-in API endpoints
- Add PDF ticket generation with QR codes (pdfkit)
- Add admin QR scanner page with camera support
- Add admin site settings page
- Update email templates with PDF ticket download link
- Add checked_in_by_admin_id field for audit tracking
- Update booking success page with ticket download
- Various UI improvements to events and booking pages

frontend/src/app/(public)/components/NewsletterSection.tsx

@@ -8,7 +8,7 @@ export default function NewsletterSection() {
   const { t } = useLanguage();
 
   return (
-    <section className="section-padding bg-primary-dark text-white">
+    <section className="section-padding text-white" style={{ backgroundColor: '#002F44' }}>
       <div className="container-page">
         <div className="max-w-2xl mx-auto text-center">
           <SparklesIcon className="w-12 h-12 mx-auto text-primary-yellow" />