This is the public URL that QR codes will encode. When employees scan their QR code from mobile data (not on office WiFi),
their phone will open this URL. Set this to your Cloudflare Tunnel domain (e.g., https://pantry.ng9holding.com).
Leave empty to use the current server address (works only on office WiFi).
✅ Settings saved! QR codes will now use the new base URL.