Preserve source provenance in multi-input conflict UX

General lesson: when a verifier combines discrepancies from several inputs into one conflict array, every persisted conflict should retain source-pair provenance, and UI copy must derive from that provenance. A generic statement such as “front and barcode differ” is misleading when the actual mismatch is submitted form versus license, or when a whole-name helper expands one changed component into multiple field flags. This applies to multi-source identity/document checks; it does not decide whether a mismatch should block verification, which remains product policy.