ApplyReservationPreCheckAsync on EquipmentImportBatchService queries active
ExternalIdReservation rows in a single round-trip at parse time; rows whose ZTag
or SAPID is claimed by a different EquipmentUuid are moved from AcceptedRows to
RejectedRows with a descriptive reason. ImportEquipment.razor calls the check
after EquipmentCsvImporter.Parse so conflicts appear in the preview before the
operator clicks Stage + Finalise. Updated notice banner to reflect the pre-check
is now live; 6 new unit tests cover conflict, no-conflict, same-UUID, released-
reservation, and empty-input paths.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>