fix(web): preserve angle-bracketed text in chat user questions

Add a remarkPreserveHtml remark plugin that converts HTML MDAST nodes
to text nodes before the references plugin runs. This prevents text
like <id> from being parsed as HTML tags and stripped by sanitization,
while keeping @file:{...} reference rendering intact.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: msukkari

packages/web/src/features/chat/components/chatThread/chatThreadListItem.tsx

@@ -334,6 +334,7 @@ const ChatThreadListItemComponent = forwardRef<HTMLDivElement, ChatThreadListIte
                             <MarkdownRenderer
                                 content={userQuestion.trim()}
                                 className="prose-p:m-0"
+                                escapeHtml={true}
                             />
                         </div>
 

packages/web/src/features/chat/components/chatThread/markdownRenderer.tsx

@@ -80,6 +80,27 @@ function remarkReferencesPlugin() {
     }
 }
 
+/**
+ * A remark plugin that converts `html` MDAST nodes into `text` nodes,
+ * preserving angle-bracketed content like `<id>` as visible text. Without this,
+ * `<id>` is parsed as an HTML tag and then stripped by sanitization.
+ *
+ * This plugin must run BEFORE remarkReferencesPlugin so that the file-reference
+ * HTML nodes created by that plugin are left intact for rehypeRaw to process.
+ */
+function remarkPreserveHtml() {
+    return function (tree: Nodes) {
+        visit(tree, 'html', (node, index, parent) => {
+            if (index !== undefined && parent && 'children' in parent) {
+                (parent.children as Nodes[])[index] = {
+                    type: 'text',
+                    value: (node as { value: string }).value,
+                };
+            }
+        });
+    };
+}
+
 const remarkTocExtractor = () => {
     return function (tree: Nodes) {
         visit(tree, 'heading', (node: Heading) => {
@@ -101,18 +122,24 @@ const remarkTocExtractor = () => {
 interface MarkdownRendererProps {
     content: string;
     className?: string;
+    /**
+     * When true, angle-bracketed text like `<id>` is preserved as visible text
+     * instead of being parsed as HTML. File references (@file:{...}) are unaffected.
+     */
+    escapeHtml?: boolean;
 }
 
-const MarkdownRendererComponent = forwardRef<HTMLDivElement, MarkdownRendererProps>(({ content, className }, ref) => {
+const MarkdownRendererComponent = forwardRef<HTMLDivElement, MarkdownRendererProps>(({ content, className, escapeHtml = false }, ref) => {
     const router = useRouter();
 
     const remarkPlugins = useMemo((): PluggableList => {
         return [
             remarkGfm,
+            ...(escapeHtml ? [remarkPreserveHtml] : []),
             remarkReferencesPlugin,
             remarkTocExtractor,
         ];
-    }, []);
+    }, [escapeHtml]);
 
     const rehypePlugins = useMemo((): PluggableList => {
         return [