Save Sandbox Partial Results

Save partial deliverables when the sandbox is interrupted (timeout/SIGTERM).

If all three result files (deliverables_json, final_report, curation_report) are present, the run is marked complete. Otherwise the run flips to failed (only when still running — a concurrent stop_run keeps its stopped status) with whatever partial data was provided.

Args: run_id: Run UUID from the path. body: Partial results payload + error_message. callback_token: One-time token issued at run creation.

Raises: HTTPException 401: Token invalid or run already finalized. HTTPException 404: Run not found.