fix: codeblock rendering issue

src/lib/components/chat/Messages/CodeBlock.svelte

@@ -4,7 +4,7 @@
 	import hljs from 'highlight.js';
 	import 'highlight.js/styles/github-dark.min.css';
 	import { loadPyodide } from 'pyodide';
-	import { tick } from 'svelte';
+	import { onMount, tick } from 'svelte';
 	import PyodideWorker from '$lib/workers/pyodide.worker?worker';
 
 	export let id = '';
@@ -12,6 +12,7 @@
 	export let lang = '';
 	export let code = '';
 
+	let highlightedCode = null;
 	let executing = false;
 
 	let stdout = null;
@@ -202,11 +203,12 @@ __builtins__.input = input`);
 		};
 	};
 
-	$: highlightedCode = code ? hljs.highlightAuto(code, hljs.getLanguage(lang)?.aliases).value : '';
+	$: if (code) {
+		highlightedCode = hljs.highlightAuto(code, hljs.getLanguage(lang)?.aliases).value || code;
+	}
 </script>
 
-{#if code}
-	<div class="mb-4" dir="ltr">
+<div class="mb-4" dir="ltr">
 	<div
 		class="flex justify-between bg-[#202123] text-white text-xs px-4 pt-1 pb-0.5 rounded-t-lg overflow-x-auto"
 	>
@@ -257,5 +259,4 @@ __builtins__.input = input`);
 			<div class="text-sm">{stdout || stderr || result}</div>
 		</div>
 	{/if}
-	</div>
-{/if}
+</div>

src/lib/components/chat/Messages/ResponseMessage.svelte

@@ -440,8 +440,8 @@
 									{#if token.type === 'code'}
 										<CodeBlock
 											id={`${message.id}-${tokenIdx}`}
-											lang={token.lang}
-											code={revertSanitizedResponseContent(token.text)}
+											lang={token?.lang ?? ''}
+											code={revertSanitizedResponseContent(token?.text ?? '')}
 										/>
 									{:else}
 										{@html marked.parse(token.raw, {