S3 backup to MinIO fails with default endpoint configuration

S3 backup operations fail when using MinIO or other S3-compatible storage because the default BACKUP_S3_ENDPOINT value points to s3.amazonaws.com instead of the MinIO endpoint URL

Set backups.s3.envconfig.BACKUP_S3_ENDPOINT to your MinIO server URL in values.yaml. For example, use the MinIO service endpoint like http://minio.default.svc.cluster.local:9000. Also verify BACKUP_S3_USE_SSL matches your MinIO SSL configuration.