feat: 生成中禁用返回按钮

frontend/src/app/workspace/chats/[thread_id]/page.tsx

@@ -63,7 +63,7 @@ export default function ChatPage() {
     isMock,
     showWelcomeStyle,
   } = useThreadChat();
-  
+
   // 新逻辑：历史渲染和新会话仅由路由 /chats/new 控制，不再读取 isnew/is_chatting 参数。
   const shouldRenderHistory = !showWelcomeStyle;
   const createNewSession = useMemo(() => isNewThread, [isNewThread]);
@@ -99,8 +99,8 @@ export default function ChatPage() {
     onStart: (currentThreadId) => {
       setIsNewThread(false);
       // if (!shouldStayOnNewRoute) {
-        // Keep /new in history so router.back() can return to it.
-        router.replace(`/workspace/chats/${currentThreadId}?is_chatting=true`);
+      // Keep /new in history so router.back() can return to it.
+      router.replace(`/workspace/chats/${currentThreadId}?is_chatting=true`);
       // }
       // history.pushState(null, "", pathOfThread(currentThreadId));
     },
@@ -193,6 +193,7 @@ export default function ChatPage() {
 
   const todoListCollapsed = true;
   const [showExitDialog, setShowExitDialog] = useState(false);
+  const isStreaming = isUploading || thread.isLoading;
   const handleSubmit = useCallback(
     (message: Parameters<typeof sendMessage>[1]) => {
       if (isSelectedSkillBootstrapping) {
@@ -222,10 +223,10 @@ export default function ChatPage() {
     setArtifactsOpen,
     setIsNewThread,
   ]);
-  
+
 
   return (
-    <ThreadContext.Provider value={{ threadId,thread }}>
+    <ThreadContext.Provider value={{ threadId, thread }}>
       <div
         className={cn(
           "m-auto flex h-screen min-h-svh overflow-hidden rounded-t-[20px] transition-[width] duration-300 ease-in-out",
@@ -252,6 +253,7 @@ export default function ChatPage() {
                     size="sm"
                     variant="ghost"
                     className="px-[10px] py-[5px] text-sm font-medium text-[#150033] hover:text-[#150033]/80"
+                    disabled={isStreaming}
                     onClick={() => setShowExitDialog(true)}
                   >
                     <svg
@@ -354,6 +356,7 @@ export default function ChatPage() {
             <div
               className={cn(
                 "h-full w-full transition-transform duration-300 ease-in-out",
+                showWelcomeStyle && !hasSubmitted ? "translate-x-0" : "",
                 artifactPanelOpen ? "translate-x-0" : "translate-x-full",
               )}
             >
@@ -475,7 +478,7 @@ export default function ChatPage() {
               <DevDialogTitle>提示</DevDialogTitle>
             </DevDialogHeader>
             <p className="text-muted-foreground text-sm">
-             （测试中：计划销毁但是现在没有销毁） 退出后，当前会话结束并销毁，请先下载保存当前结果！
+              （测试中：计划销毁但是现在没有销毁） 退出后，当前会话结束并销毁，请先下载保存当前结果！
             </p>
             <DevDialogFooter>
               <Button