fix(migration): make Phase B additive sync actually work + verify end-to-end

The --sync path had never been run and was broken in several ways. Fixed and
verified against the dev DB (two consecutive syncs, both exit 0, 32/32
assertions: stable PKs, manual-row preservation, changed-row updates,
legacy-delete, no child duplication, zero FK orphans; idempotent).

- policies/properties: reuse each legacy row's existing id (by provenance)
  BEFORE building child rows, so children no longer point at a discarded fresh
  uuid; rebuild legacy-owned children via scoped delete + reinsert.
- customers: replace zip(customers, refs) (mispaired almost every row) with a
  ref-grouped id remap; names now restore and no spurious customers appear.
- drop the invalid Vehicle @@unique(legacySourceTable, legacyId) — one legacy
  policy row carries up to 3 vehicles sharing a legacyId; handle via delete+reinsert.
- upsert lookup tables (policy_types, insurance_providers, type_transactions,
  adjusters) by natural name and remap child FKs instead of inserting fresh
  uuids that nothing points at.
- transactions: drop updatedAt=NOW() (no such column); guard report formatting
  on NULL legacySourceTable (manual rows). Same report guard in bank.
- add manual-safe prune (prune_empty_customers.py --sync, in SYNC_STEPS): prune
  only legacy-owned empties, never manually-added customers.

web: customer-detail mini tx list now strikes voided rows with an "(anulado)"
tag (was the last void-UI rendering gap; /estado-cuenta already handled it).

docs: RESUME.md updated — Phase B sync marked verified end-to-end, void-UI
browser pass recorded.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

packages/database/prisma/schema.prisma

@@ -221,10 +221,12 @@ model Vehicle {
   vinNumber         String?
   stateCode         String?
   notes             String? @db.Text
+  // One legacy policy row can carry up to 3 vehicles, so they share a
+  // legacyId (the source row number) — provenance is NOT unique per vehicle.
+  // Sync rebuilds legacy vehicles by scoped delete + reinsert instead of upsert.
   legacySourceTable String?
   legacyId          String?
 
-  @@unique([legacySourceTable, legacyId])
   @@map("vehicles")
 }