- unit tests for resolve_group_ambiguity (distinct addresses withheld,
same-address re-listing kept, order preserved)
- Postgres integration tests for upsert_all's backstop dedup
- ADR-0057 recording the "confirm UPRNs before finalise" decision
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>