Use <once-button> for app settings form

tailbone/templates/appsettings.mako

@@ -99,13 +99,15 @@
         </div><!-- panel-body -->
       </div><! -- panel -->
   % endfor
-  % endif
 
   <div class="buttons">
     ${h.submit('save', getattr(form, 'submit_label', getattr(form, 'save_label', "Submit")), class_='button is-primary')}
     ${h.link_to("Cancel", form.cancel_url, class_='cancel button{}'.format(' autodisable' if form.auto_disable_cancel else ''))}
   </div>
 
+  ## end of legacy (not buefy)
+  % endif
+
   ${h.end_form()}
 </div>
 
@@ -181,6 +183,16 @@
           </div><!-- card-content -->
         </div><!-- card -->
 
+        <div class="buttons">
+          <once-button type="is-primary"
+                       native-type="submit"
+                       text="${getattr(form, 'submit_label', getattr(form, 'save_label', "Submit"))}">
+          </once-button>
+          <once-button tag="a" href="${form.cancel_url}"
+                       text="Cancel">
+          </once-button>
+        </div>
+
       </div><!-- app-wrapper -->
     </script>