Add multi-league foundation

app/templates/qr/set_detail.html

@@ -3,7 +3,7 @@
 <div class="max-w-6xl mx-auto p-4">
   <div class="mb-8">
     <div class="flex items-center">
-      <a href="/qr" class="text-irish-green hover:underline mr-4">
+      <a href="/qr{% if qr_set.league_id %}/?league_id={{ qr_set.league_id }}{% endif %}" class="text-irish-green hover:underline mr-4">
         <i class="fas fa-arrow-left"></i> Back to Dashboard
       </a>
       <h1 class="text-3xl font-bold text-irish-green">{{ qr_set.name }}</h1>
@@ -11,7 +11,9 @@
     {% if qr_set.description %}
       <p class="text-gray-600 mt-2">{{ qr_set.description }}</p>
     {% endif %}
-    <p class="text-sm text-gray-500 mt-1">Created on {{ qr_set.created_at.strftime('%Y-%m-%d') }}</p>
+    <p class="text-sm text-gray-500 mt-1">
+      {{ qr_set.league.name if qr_set.league else "Default League" }} • Created on {{ qr_set.created_at.strftime('%Y-%m-%d') }}
+    </p>
   </div>
 
   <div class="grid md:grid-cols-3 gap-8">
@@ -270,4 +272,4 @@
     }
   });
 </script>
-{% endblock %}
+{% endblock %}