重构组件，优化性能并移除不必要的属性；撤销滚动条修改；

src/components/chat/GlobalChatbox.tsx

@@ -30,10 +30,8 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
   );
 
   const bottomRef = useRef<HTMLDivElement>(null);
-  const workspaceRef = useRef<HTMLDivElement | null>(null);
   const composerRef = useRef<AgentComposerHandle | null>(null);
   const hasResetForOpenRef = useRef(false);
-  const shouldAutoScrollRef = useRef(true);
   const theme = useTheme();
   const currentProjectId = useProjectStore((state) => state.currentProjectId);
 
@@ -84,20 +82,11 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
     getModel: () => selectedModel,
   });
 
-  const syncAutoScrollState = useCallback(() => {
-    const container = workspaceRef.current;
-    if (!container) return;
-    const distanceFromBottom =
-      container.scrollHeight - container.scrollTop - container.clientHeight;
-    shouldAutoScrollRef.current = distanceFromBottom <= 120;
-  }, []);
-
   const scrollToBottom = useCallback((behavior: ScrollBehavior = "smooth") => {
     bottomRef.current?.scrollIntoView({ behavior });
   }, []);
 
   useEffect(() => {
-    if (!shouldAutoScrollRef.current) return;
     scrollToBottom(isStreaming ? "auto" : "smooth");
   }, [isStreaming, messages, scrollToBottom]);
 
@@ -110,7 +99,6 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
     hasResetForOpenRef.current = true;
 
     const timer = window.setTimeout(() => {
-      shouldAutoScrollRef.current = true;
       createSession();
       composerRef.current?.clear();
       setIsHistoryOpen(false);
@@ -122,14 +110,12 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
 
   const handleSend = useCallback((prompt: string) => {
     if (isStreaming) return;
-    shouldAutoScrollRef.current = true;
     void sendPrompt(prompt);
   }, [isStreaming, sendPrompt]);
 
   const handleNewConversation = useCallback(() => {
     handleStopSpeech();
     stopListening();
-    shouldAutoScrollRef.current = true;
     createSession();
     composerRef.current?.clear();
     window.setTimeout(() => {
@@ -144,17 +130,12 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
 
   const handleSelectSession = useCallback(
     (storageSessionId: string) => {
-      shouldAutoScrollRef.current = true;
       composerRef.current?.clear();
       void switchSession(storageSessionId);
     },
     [switchSession],
   );
 
-  const handleWorkspaceScroll = useCallback(() => {
-    syncAutoScrollState();
-  }, [syncAutoScrollState]);
-
   const handleDeleteSession = useCallback(
     (storageSessionId: string) => {
       void removeSession(storageSessionId);
@@ -334,8 +315,6 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
               branchGroups={branchGroups}
               branchTransition={branchTransition}
               isStreaming={isStreaming}
-              scrollContainerRef={workspaceRef}
-              onScroll={handleWorkspaceScroll}
               bottomRef={bottomRef}
               speakingMessageId={speakingMessageId}
               speechState={speechState}