feat: 实现ai 聊天从底部向上滚动一部分距离时，取消自动滚动到底部

src/views/AIRobotChat/src/AIRobotChat.vue

@@ -246,6 +246,7 @@ function handleScroll() {
   isShowHeaderShadow.value = !!messagesRef.value?.scrollTop
 }
 function scrollToBottom() {
+  if (!autoScroll.value || !messagesRef.value) return
   nextTick(() => {
     if (messagesRef.value) {
       messagesRef.value.scrollTop = messagesRef.value.scrollHeight