curl --request POST \
  --url https://api.clovastudio.go.kr/v1/rag42/collections/{collection_id}/documents/upload \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --form 'metadata={"author": "홍길동", "department": "개발팀"}' \
  --form 'indexed_fields=author,department' \
  --form external_id=doc-12345 \
  --form external_id_field=uuid \
  --form file=@example-file

{
  "status": {
    "code": "20000",
    "message": "OK"
  },
  "result": {
    "document_id": "ed5754eec78e4e0783ce075549ccadaa",
    "document_name": "2024년_업무추진계획.pdf",
    "file_size": 2458624,
    "collection_id": "ef7483af16d84818a59dcbcf8b587b93",
    "uploaded_at": "2024-10-18T12:00:00Z",
    "operation": "upload_document",
    "ingest_config": {
      "chunking_strategy": "by_title",
      "chunk_size": 1000,
      "chunk_overlap": 100,
      "embedding_model": "bge-m3",
      "embedding_dimension": 1024,
      "pii_mask": true,
      "parser_model": "rag42-chunk-v1",
      "indexed_fields": [
        "author",
        "department",
        "document_type"
      ],
      "external_id_field": "document_number"
    }
  }
}