Retrieve file metadata by ID.
curl https://gateway.bud.studio/v1/files/file-abc123 \ -H "Authorization: Bearer YOUR_API_KEY"
{ "id": "file-abc123", "object": "file", "bytes": 2048, "created_at": 1699000000, "filename": "batch_requests.jsonl", "purpose": "batch", "status": "processed", "status_details": null }