chore(web): migration svelte 5 syntax (#13883)

web/src/routes/(user)/+layout.svelte

@@ -1,13 +1,21 @@
 <script lang="ts">
+  import { run } from 'svelte/legacy';
+
   import UploadCover from '$lib/components/shared-components/drag-and-drop-upload-overlay.svelte';
   import { page } from '$app/stores';
 
   import { assetViewingStore } from '$lib/stores/asset-viewing.store';
+  import type { Snippet } from 'svelte';
+  interface Props {
+    children?: Snippet;
+  }
+
+  let { children }: Props = $props();
   let { isViewing: showAssetViewer, setAsset, gridScrollTarget } = assetViewingStore;
 
   // $page.data.asset is loaded by route specific +page.ts loaders if that
   // route contains the assetId path.
-  $: {
+  run(() => {
     if ($page.data.asset) {
       setAsset($page.data.asset);
     } else {
@@ -15,11 +23,11 @@
     }
     const asset = $page.url.searchParams.get('at');
     $gridScrollTarget = { at: asset };
-  }
+  });
 </script>
 
 <div class:display-none={$showAssetViewer}>
-  <slot />
+  {@render children?.()}
 </div>
 <UploadCover />