Function finalizeDatasetUpload

Finalize an uploaded file and start ingest Call once the file has been PUT to the upload.url from POST /datasets (or from POST /datasets/{datasetId}/uploads). Enqueues ingest and returns immediately; poll GET /datasets/{datasetId}/uploads/{uploadId} for the result.

Idempotent while the upload is still open — a repeat finalize before it has produced a version returns the same jobId rather than enqueueing a second ingest. Once it HAS produced a version, uploadId is spent: finalizing it again is a 409, even with different bytes freshly PUT to the same URL — open a new upload session instead (POST /datasets/{datasetId}/uploads) rather than reusing a spent one.