ErrorCode:
| "INVALID_PDF"
| "PASSWORD_REQUIRED"
| "INVALID_PASSWORD"
| "INVALID_ARGUMENT"
| "DOCUMENT_CLOSED"
| "ABORTED"
| "UNSUPPORTED_PDF_FEATURE"
| "UNSUPPORTED_IMAGE_FEATURE"
| "IMAGE_NOT_FOUND"
| "RESOURCE_LIMIT_EXCEEDED"
| "TEXT_EXTRACTION_FAILED"
| "OCR_PROVIDER_REQUIRED"
| "OCR_FAILED"
| "OCR_ASSET_UNAVAILABLE"
| "INVALID_STORAGE_KEY"
| "STORAGE_NOT_FOUND"
| "STORAGE_PERMISSION_DENIED"
| "STORAGE_IO_ERROR"
| "STORAGE_CAPABILITY_UNSUPPORTED"
| "CONTENT_LENGTH_MISMATCH"
| "MULTIPART_UPLOAD_FAILED"
| "COMMIT_OUTCOME_UNKNOWN"
Stable machine-readable failures across extraction, OCR and storage. COMMIT_OUTCOME_UNKNOWN requires reconciliation.