Privileges: GAIA_MODIFY

Uploads a single file to the backend for on-demand dataset creation.
The file content is streamed as binary data (application/octet-stream) in the request body.
File metadata must be provided via HTTP headers:

• X-File-Name: The original filename (required)
• X-File-Path: The full file path preserving directory structure (optional)
• X-File-Size: The file size in bytes (required)
• X-Upload-Session-ID: The upload session ID to group files uploaded together (required)

The uploaded file will be stored in the configured object store (S3 or Azure Blob Storage)
and associated with the dataset.