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

backend/src/routes/events.ts

@@ -28,6 +28,8 @@ const baseEventSchema = z.object({
   titleEs: z.string().optional().nullable(),
   description: z.string().min(1),
   descriptionEs: z.string().optional().nullable(),
+  shortDescription: z.string().max(300).optional().nullable(),
+  shortDescriptionEs: z.string().max(300).optional().nullable(),
   startDatetime: z.string(),
   endDatetime: z.string().optional().nullable(),
   location: z.string().min(1),
@@ -315,6 +317,8 @@ eventsRouter.post('/:id/duplicate', requireAuth(['admin', 'organizer']), async (
     titleEs: existing.titleEs ? `${existing.titleEs} (Copia)` : null,
     description: existing.description,
     descriptionEs: existing.descriptionEs,
+    shortDescription: existing.shortDescription,
+    shortDescriptionEs: existing.shortDescriptionEs,
     startDatetime: existing.startDatetime,
     endDatetime: existing.endDatetime,
     location: existing.location,