feat(container-returns): show booking ref, company and return time

The returns table renders one list holding both booking-linked and standalone
empty returns, but a booking-linked row showed the literal string Associated
in place of its reference, and nothing showed the owning company.

listEmptyReturns becomes a raw projection joining freight.bookings and
freight.companies, so each row carries bookingReference and a companyName that
falls back to the booking's company when none was typed on the return itself.

Return date was collected as a bare date input, storing every return at 00:00.
All three entry points — booking-linked, standalone and the bulk default — now
use datetime-local seeded from local time rather than UTC, and the column
renders date and time.

apps/edr-freight-web/backoffice/src/lib/format.ts

@@ -60,3 +60,10 @@ export function formatBytes(bytes: number): string {
   const value = bytes / Math.pow(1024, i);
   return `${value.toFixed(i === 0 ? 0 : 1)} ${units[i]}`;
 }
+
+/** `YYYY-MM-DDTHH:mm` for now, in local time — what `datetime-local` expects. */
+export function localNowForInput(): string {
+  const d = new Date();
+  d.setMinutes(d.getMinutes() - d.getTimezoneOffset());
+  return d.toISOString().slice(0, 16);
+}