Make asking for missing pieces in forms optional

app/views/completions/_form.html.slim

@@ -78,6 +78,7 @@
         javascript:
           savetime = "";
           ispatch = #{method == :patch};
+          showMissingPieces = #{@completion.contest.missing_pieces}
 
           // Actions for radio buttons.
           completed_radio_yes_el = document.getElementById('completed_radio_yes');
@@ -90,7 +91,7 @@
             if (ispatch) timeEl.value = '#{@completion.display_time_from_start}';
             else timeEl.value = savetime;
             timeEl.parentElement.parentElement.parentElement.style.display = '';
-            missingPiecesEl.style.display = 'block';
+            if (showMissingPieces) missingPiecesEl.style.display = 'block';
             remainingPiecesEl.style.display = 'none';
             submitEl.style.display = '';
             if (refreshEl) refreshEl.style.display = '';
@@ -150,7 +151,7 @@
           updateTime();
   
     / Text field for recording the missing pieces, if any.
-    .row.mt-3 id="missing_pieces" style="display: #{@completion.completed ? "" : "none"};"
+    .row.mt-3 id="missing_pieces" style="display: #{@completion.completed && @completion.contest.missing_pieces ? "" : "none"};"
       .col
         .form-floating
           = form.text_field :missing_pieces, autocomplete: "off", class: "form-control"

app/views/contests/settings_onsite_edit.html.slim

@@ -10,13 +10,17 @@
       .form-check.form-switch
         = form.check_box :organizer_form, class: "form-check-input"
         = form.label :organizer_form
-      .form-text = t("activerecord.attributes.contest.organizer_form")
   .row.mt-3.mb-3
     .col
       .form-floating
         = form.text_field :code, autocomplete: "off", class: "form-control"
         = form.label :code, class: "required"
         .form-text = t("activerecord.attributes.contest.code_description")
+  .row.mt-1
+    .col
+      .form-check.form-switch
+        = form.check_box :missing_pieces, class: "form-check-input"
+        = form.label :missing_pieces
   .row.mt-4
     .col
       = form.submit t("helpers.buttons.update"), class: "btn btn-primary"