Attests attribute-level data lineage for a model's input data, which source system, which field, what transformation was applied, feeding which model run, distinct from every existing model-risk node (art-450/451/453/488/489), none of which attest where a model's input data came from, only what the model did with declared inputs. Input attributes are SUPPLIED and asserted by the caller (zero-egress); this node never fetches or validates against a live data warehouse or source system. An attribute declared without a source_system is reported as a legitimate finding (unmapped_attribute_count), never silently dropped or treated as an error. run_ref is optional, a caller with no model-run artifact yet still gets a valid lineage receipt. ECB Guide on effective risk data aggregation and risk reporting (May 2024) §3.4(3) requires complete, up-to-date data lineages on data attribute level for the risk indicators and critical data elements within scope; this node gives that its own citable artifact. SR 26-2 (effective 2026-04-17) scopes the model-risk context to conventional quantitative models only. Feeds the model-risk-lineage-pack chain (art-562) as an optional additional citation, never a required one.
compute_proof_ready: deferred. No formal correctness proof has been produced for this kernel; the result above is a deterministic recompute, verified by a property-test floor, not a proven one.