feat: Add cron job for audit logs cleanup

- Add cleanupAuditLogs.js with daily cleanup job
- Delete audit logs older than 7 days
- Runs every day at midnight (00:00)
- Export cleanupOldAuditLogs for manual triggers

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/cron/index.js

@@ -1,5 +1,6 @@
 import { logger } from '../utils/logger.js';
 import { startCalendarNotificationCron, triggerEventNotifications, triggerSingleEventNotification } from './calendar/index.js';
+import { startAuditCleanupCron, cleanupOldAuditLogs } from './cleanupAuditLogs.js';
 
 /**
  * Start all cron jobs
@@ -10,8 +11,11 @@ export const startAllCronJobs = () => {
   // Calendar event notifications
   startCalendarNotificationCron();
 
+  // Audit logs cleanup (daily at midnight)
+  startAuditCleanupCron();
+
   logger.info('=== Všetky cron jobs inicializované ===');
 };
 
 // Export individual functions for testing/manual triggers
-export { triggerEventNotifications, triggerSingleEventNotification };
+export { triggerEventNotifications, triggerSingleEventNotification, cleanupOldAuditLogs };