webui: update DEAR_LLM.md, rm .shadowRoot refs
diff --git a/webui/src/web-components/sketch-timeline.ts b/webui/src/web-components/sketch-timeline.ts
index 9eca07a..d6928c7 100644
--- a/webui/src/web-components/sketch-timeline.ts
+++ b/webui/src/web-components/sketch-timeline.ts
@@ -731,7 +731,7 @@
     );
 
     // Set up scroll listener if container is available
-    if (this.scrollContainer.value) {
+    if (this.scrollContainer?.value) {
       this.addScrollListener(this.scrollContainer.value);
     }