Allow dropping cards into closed

app/controllers/cards/drops_controller.rb

@@ -8,7 +8,7 @@ class Cards::DropsController < ApplicationController
   end
 
   private
-    VALID_DROP_TARGETS = %w[ considering on_deck doing ]
+    VALID_DROP_TARGETS = %w[ considering on_deck doing closed ]
 
     def set_card
       @card = Current.user.accessible_cards.find(params[:dropped_item_id])
@@ -30,6 +30,8 @@ class Cards::DropsController < ApplicationController
         @card.move_to_on_deck
       when :doing
         @card.engage
+      when :closed
+        @card.close
       end
     end
 

app/views/cards/index/engagement/_closed.html.erb

@@ -1,4 +1,6 @@
 <section id="closed-cards" class="cards cards--closed is-collapsed" style="--card-color: var(--color-card-complete);"
+    data-drag-and-drop-target="container"
+    data-drop-target="closed"
     data-collapsible-columns-target="column">
   <div class="cards__expander btn btn--plain" data-action="click->collapsible-columns#toggle">
     <strong class="cards__expander-count"><%= page.records.count > 99 ? "99+" : page.records.count %></strong>