}
        } else {
            // Production: use credentials file or default credentials
            final String credentialsFile = getInitParameter("credentialsFile", null, String.class);
            if (StringUtil.isNotBlank(credentialsFile)) {
                try (InputStream is = new FileInputStream(credentialsFile)) {
                    builder.setCredentials(ServiceAccountCredentials.fromStream(is));

### Cloud Storage Clients

- **S3Client**: AWS SDK v2, `s3://bucket/path`, properties: `endpoint`, `accessKey`, `secretKey`, `region`
- **GcsClient**: Google Cloud SDK, `gcs://bucket/path`, properties: `projectId`, `credentialsFile`, `endpoint`
- **StorageClient**: MinIO SDK, `storage://bucket/path`

### Services

- **UrlQueueService**: URL queue management (FIFO), duplicate detection
- **DataService**: Access result persistence, iteration