The tenancy merchant detail page now reads an optional ?back= query
parameter to determine the back button destination. Falls back to
/admin/merchants when no param is present (default behavior preserved).
The loyalty merchant detail "View Merchant" link now passes
?back=/admin/loyalty/merchants/{id} so clicking back from the tenancy
page returns to the loyalty context instead of the merchants list.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>