The last of SH-271's five acceptance bullets. The Work Order Vendor dialog
gets one composed address line from the vendor dropdown payload, not the
structured parts the form and detail drawer hold, so the preview takes the
line directly — it is saved data either way, and the completeness rule exists
to stop a map of half-typed input, not to reject a stored address.
The dialog's hand-built maps URL now goes through the shared helper, so the
link and the preview cannot drift apart.