Response–Row Identity Across Promote — Why Responses Outlive Their Rows, and the `record_uuid`-on-Response Fix

Responses live in response-store. Rows live in row-store. When `record_set.promote` folds a parent set into a canonical, the **parent rows are deleted and new canonical rows are minted with fresh row_ids** — but the old responses survive untouched, still pointing at row_ids that no longer exist. Today there's no link from those orphaned responses back to the canonical row that inherited their accepted value, because the stable cross-derivation identity (`record_uuid`) lives only on rows, not on responses. The fix is small and additive: carry `record_uuid` on the ResponseRecord at create time, and the by-record view can resolve orphans by identity instead of by dead row_id.