Set Web IDE live preview bg to white

app/assets/javascripts/ide/components/preview/clientside.vue

@@ -152,7 +152,7 @@ export default {
 </script>
 
 <template>
-  <div class="preview h-100 w-100 d-flex flex-column">
+  <div class="preview h-100 w-100 d-flex flex-column gl-bg-white">
     <template v-if="showPreview">
       <navigator :manager="manager" />
       <div id="ide-preview"></div>

changelogs/unreleased/281026-set-live-preview-bg-white.yml

+---
+title: Set Web IDE Live Preview default background to white
+merge_request: 49901
+author:
+type: fixed