Fix: cancel scroll-to-bottom debouncer on unmount to prevent stale state updates

Author: cursoragent

apps/web/src/components/ChatView.tsx

@@ -1969,6 +1969,12 @@ export default function ChatView(props: ChatViewProps) {
     planSidebarDismissedForTurnRef.current = null;
   }, [activeThread?.id]);
 
+  // Cancel any pending debouncer timeout on unmount to avoid stale state updates.
+  useEffect(() => {
+    const debouncer = showScrollDebouncer.current;
+    return () => debouncer.cancel();
+  }, []);
+
   useEffect(() => {
     setIsRevertingCheckpoint(false);
   }, [activeThread?.id]);