Authentication configuration. Requirements depend on sourceType:
S3_BUCKET: roleARN is required, azureAppID, azureDirectoryID, and alibabaOidcProviderARN must be null
AZURE_BLOB: azureAppID and azureDirectoryID are required, roleARN and alibabaOidcProviderARN must be null
GCP_BIGQUERY: all fields must be null (uses service account authentication)
GCS_BUCKET: all fields must be null (uses service account authentication)
GCS_UPLOAD: all fields must be null (managed BYOD bucket for drag-and-drop uploads, no external auth)
OSS_BUCKET: roleARN and alibabaOidcProviderARN are required, azureAppID and azureDirectoryID must be null