Fix category comma rendering in popup details window

Co-authored-by: ProLoser <67395+ProLoser@users.noreply.github.com>

Author: Copilot

map.js

@@ -486,7 +486,7 @@ class Events {
           <p>
             ${event.cost_details}
           </p>
-          <p class="categories">Categories: ${event.categories.map(category => `<a onclick="filter({category:'${category}'})">${category}</a>`).join('')}</p>
+          <p class="categories">Categories: ${event.categories.map(category => `<a onclick="filter({category:'${category}'})">${category}</a>`).join(', ')}</p>
         </div>
         <div class="info-body">
           <details ${expanded ? 'open' : ''}>