Add PostgreSQL support with SQLite/Postgres database compatibility layer

- Add dbGet/dbAll helper functions for database-agnostic queries
- Add toDbBool/convertBooleansForDb for boolean type conversion
- Add toDbDate/getNow for timestamp type handling
- Add generateId that returns UUID for Postgres, nanoid for SQLite
- Update all routes to use compatibility helpers
- Add normalizeEvent to return clean number types from Postgres decimal
- Add formatPrice utility for consistent price display
- Add legal pages admin interface with RichTextEditor
- Update carousel images
- Add drizzle migration files for PostgreSQL

frontend/src/app/(public)/events/[id]/EventDetailClient.tsx

@@ -5,6 +5,7 @@ import Link from 'next/link';
 import Image from 'next/image';
 import { useLanguage } from '@/context/LanguageContext';
 import { eventsApi, Event } from '@/lib/api';
+import { formatPrice } from '@/lib/utils';
 import Card from '@/components/ui/Card';
 import Button from '@/components/ui/Button';
 import ShareButtons from '@/components/ShareButtons';
@@ -186,7 +187,7 @@ export default function EventDetailClient({ eventId, initialEvent }: EventDetail
                 <p className="text-4xl font-bold text-primary-dark">
                   {event.price === 0 
                     ? t('events.details.free')
-                    : `${event.price.toLocaleString()} ${event.currency}`}
+                    : formatPrice(event.price, event.currency)}
                 </p>
               </div>