fix(tenancy): use Python .lower() instead of JS .toLowerCase() in template

Merchant team page called .toLowerCase() on a Jinja2 string (Python),
causing UndefinedError. Fixed to .lower().

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/modules/tenancy/templates/tenancy/merchant/team.html

@@ -52,7 +52,7 @@
                     </div>
                     <div class="flex items-center gap-2">
                         <span class="text-sm text-gray-500 dark:text-gray-400"
-                              x-text="`${store.member_count} {{ _("tenancy.team.members").toLowerCase() }}`"></span>
+                              x-text="`${store.member_count} {{ _("tenancy.team.members").lower() }}`"></span>
                         <a :href="`/store/${store.store_code}/team`"
                            class="inline-flex items-center px-3 py-1.5 text-xs font-medium text-indigo-600 dark:text-indigo-400 bg-indigo-50 dark:bg-indigo-900/30 rounded-md hover:bg-indigo-100 dark:hover:bg-indigo-900/50 transition-colors">
                             <span x-html="$icon('external-link', 'w-3.5 h-3.5 mr-1')"></span>