ui: legacy: add quit button

packages/ui-default/templates/partials/footer.html

@@ -57,7 +57,13 @@
             {%- endfor -%}
             </ol>
           </li>
-          <li class="footer__extra-link-item"><a href="/legacy?legacy=true">{{ _('Enable legacy mode') }}</a></li>
+          <li class="footer__extra-link-item">
+            {% if handler.session.legacy %}
+              <a href="/legacy">{{ _('Standard mode') }}</a>
+            {% else %}
+              <a href="/legacy?legacy=true">{{ _('Legacy mode') }}</a>
+            {% endif %}
+          </li>
           <li class="footer__extra-link-item nojs--hide" data-dropdown-target="#menu-footer-theme">
             <span><span class="icon icon-global"></span> {{ _('Theme') }} <span class="icon icon-expand_less"></span></span>
             <ol class="dropdown-target menu" id="menu-footer-theme">