优化同一节课后续小节减少输入token

src/components/study/SelfDirectedLearning.vue

@@ -257,7 +257,6 @@ const generateScript = async () => {
         ',主讲人角色定位：' + role.description +
         '；助讲有：'
     let zhujiang = []
-
     selectedAssistants.value.forEach((rName) => {
       const assistantRole = localScriptRoles.value.find((r) => r.name === rName)
       zhujiang.push(assistantRole.name + '[' + assistantRole.description + ']')
@@ -281,7 +280,9 @@ const generateScript = async () => {
     for (let i = 0; i < lessonList.value.length; i++) {
       let lesson = lessonList.value[i]
       progressSteps.value[0].next = "生成课程小节【" + lesson.name + "】..."
-      content += "现在开始生成第"+(i+1)+"节课：" + lesson.name
+
+      content = i === 0 ? content + `现在开始生成第${i+1}节课：${lesson.name}` : content
+
       let lessonInfo = {courseName: lesson.name, courseLabel: lesson.id};
       await doSendMessageStream(activeConversationId.value, content, lessonInfo)
       console.log("生成课程小节信息：", lessonInfo)
@@ -305,7 +306,6 @@ const generateScript = async () => {
     //4、生成全部图片
     progressSteps.value[2].visible = true;
     progressSteps.value[2].active = true;
-    //取courseInfo.coverImage、取courseLessons[*].sections[*].backgroundImage课程小节背景图描述词；生成图片
     await generateAllImages()
     progressSteps.value[2].completed = true;
     progressSteps.value[2].active = false;
@@ -313,7 +313,6 @@ const generateScript = async () => {
     //5、生成全部配音
     progressSteps.value[3].visible = true;
     progressSteps.value[3].active = true;
-    //取courseLessons[*].sections[*].dialogues[*].voiceoverUrl课程小节课程内对话文本生成配音
     await generateAllVoiceovers()
     progressSteps.value[3].completed = true;
     progressSteps.value[3].active = false;