TODO/DONE auto-mark done when all subtasks done

Template/config/show.php

@@ -70,6 +70,9 @@
 
         <?= $this->form->checkbox('organon_tweaks_done_closes_task', t('Marking Done also closes the task'), 1, isset($values['organon_tweaks_done_closes_task']) && $values['organon_tweaks_done_closes_task'] == 1) ?>
         <p class="form-help"><?= t('When on, "Done" means the task is closed (so it leaves the board unless you clear the status filter), and clicking Todo reopens it -- native Close/Open stay in sync. When off, the badge is an independent marker that never changes the open/closed status.') ?></p>
+
+        <?= $this->form->checkbox('organon_tweaks_done_autosubtasks', t('Auto-mark Done when the last subtask is completed'), 1, isset($values['organon_tweaks_done_autosubtasks']) && $values['organon_tweaks_done_autosubtasks'] == 1) ?>
+        <p class="form-help"><?= t('When every subtask on a card is done, flip the badge to Done automatically (honoring the mode above). It only nudges at that moment -- if you then set it back to Todo, that is respected (the subtasks stay done).') ?></p>
     </fieldset>
 
     <div class="form-actions">