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/page.tsx

@@ -4,6 +4,7 @@ import { useState, useEffect } from 'react';
 import Link from 'next/link';
 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 { CalendarIcon, MapPinIcon, UserGroupIcon } from '@heroicons/react/24/outline';
@@ -149,7 +150,7 @@ export default function EventsPage() {
                         <span className="font-bold text-xl text-primary-dark">
                           {event.price === 0 
                             ? t('events.details.free')
-                            : `${event.price.toLocaleString()} ${event.currency}`}
+                            : formatPrice(event.price, event.currency)}
                         </span>
                         <Button size="sm">
                           {t('common.moreInfo')}