fix(web): prevent auto-scroll when toggling work log expansion

Expanding a work log group during a running session would trigger
scheduleStickToBottom via the timelineEntries effect, yanking the
viewport to the bottom. Disable auto-scroll on toggle so the user
stays where they clicked; the scroll-to-bottom button is shown if
they want to jump back.

Author: Marve10s

apps/web/src/components/ChatView.tsx

@@ -3435,6 +3435,11 @@ export default function ChatView({ threadId }: ChatViewProps) {
     return false;
   };
   const onToggleWorkGroup = useCallback((groupId: string) => {
+    // Disable auto-scroll so expanding/collapsing work groups doesn't
+    // yank the viewport to the bottom. The user clicked intentionally —
+    // they can use the scroll-to-bottom button if they want to jump back.
+    shouldAutoScrollRef.current = false;
+    setShowScrollToBottom(true);
     setExpandedWorkGroups((existing) => ({
       ...existing,
       [groupId]: !existing[groupId],