feat(import-operations): bulk Excel upload for yard-resident empty containers

Empties already sitting in an EDR yard but never entered in the system had
to be typed one at a time. Adds a bulk path: parse the sheet in the browser
(all-or-nothing, row-numbered errors), preview it, then POST one batch.

The server rejects the batch if any container already has a non-COMPLETED
return, so re-uploading the same sheet cannot duplicate boxes. No interchange
notification fires — these are historical rows, not a live handover.

Company is an Autocomplete over registered customers that also accepts a
typed name, since a backfilled box may belong to a company that is not a
customer yet. Exact name match sets customer_id; the name always lands in the
new empty_container_returns.company_name.

Also fixes the single Record Return modal, which collected Yard and Zone and
then dropped them before the API call, and did not invalidate the returns
list after a standalone return.

apps/edr-freight-web/backoffice/src/constants/URLS.ts

@@ -791,6 +791,7 @@ export const URL_CONSTANTS = {
     CUSTOMS_RELEASE_PERMITTED: (bookingId: string) =>
       `/import-operations/customs/${bookingId}/release-permitted`,
     EMPTY_CONTAINER_RETURNS: "/import-operations/empty-container-returns",
+    EMPTY_CONTAINER_RETURNS_BULK: "/import-operations/empty-container-returns/bulk",
     EMPTY_CONTAINER_RETURN_STATUS: (id: string) =>
       `/import-operations/empty-container-returns/${id}/status`,
     EMPTY_CONTAINER_RETURNS_LOAD_ON_TRAIN: