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)/events/[id]/page.tsx

@@ -11,6 +11,8 @@ interface Event {
   titleEs?: string;
   description: string;
   descriptionEs?: string;
+  shortDescription?: string;
+  shortDescriptionEs?: string;
   startDatetime: string;
   endDatetime?: string;
   location: string;
@@ -47,10 +49,12 @@ export async function generateMetadata({ params }: { params: { id: string } }):
   }
 
   const title = event.title;
-  // Use the beginning of the event description, truncated to ~155 chars for SEO
-  const description = event.description.length > 155
-    ? event.description.slice(0, 152).trim() + '...'
-    : event.description;
+  // Use short description if available, otherwise fall back to truncated full description
+  const description = event.shortDescription 
+    ? event.shortDescription
+    : (event.description.length > 155
+        ? event.description.slice(0, 152).trim() + '...'
+        : event.description);
 
   // Convert relative banner URL to absolute URL for SEO
   const imageUrl = event.bannerUrl