Purpose: fetch one cross-domain benchmark record by ID or keyword - full summary, issuer, status, as-of date, domain impact, confidence grade and the source URL for citation. Guidelines: pass the ID returned by query_domain_benchmarks (e.g. 'tbm-021') or a distinctive keyword; use this whenever a cross-domain fact is going to be quoted, so the citation carries a verifiable source link. Limits: one record per call; anchor facts only - carbon prices are dated snapshots rather than live quotes, and the health domain provides no diagnosis, treatment or dosing guidance. Ex: get_domain_benchmark(id='tbm-021'), get_domain_benchmark(keyword='CBAM', language='en').