fix(sync): backfill missing items for existing local pricelists

internal/services/sync/service.go

@@ -351,6 +351,15 @@ func (s *Service) SyncPricelists() (int, error) {
 		// Check if pricelist already exists locally
 		existing, _ := s.localDB.GetLocalPricelistByServerID(pl.ID)
 		if existing != nil {
+			// Backfill items for legacy/partial local caches where only pricelist metadata exists.
+			if s.localDB.CountLocalPricelistItems(existing.ID) == 0 {
+				itemCount, err := s.SyncPricelistItems(existing.ID)
+				if err != nil {
+					slog.Warn("failed to sync missing pricelist items for existing local pricelist", "version", pl.Version, "error", err)
+				} else {
+					slog.Info("synced missing pricelist items for existing local pricelist", "version", pl.Version, "items", itemCount)
+				}
+			}
 			continue
 		}