fix: 修复setTitle2函数声明并更新AI默认模型

修复index3.vue中setTitle2函数缺少const声明的问题
将aiChat.ts中的AI默认模型从gpt-4o更改为qwen-flash

src/tools/aiChat.ts

@@ -202,7 +202,8 @@ export const getTtsLanguage = (langCode: string) => {
 
 // AI 模型常量
 const AI_MODEL_CONSTANTS = {
-  DEFAULT_MODEL: 'gpt-4o-2024-11-20'
+  // DEFAULT_MODEL: 'gpt-4o-2024-11-20'
+  DEFAULT_MODEL: 'qwen-flash'
 }
 
 export const chat_no_stream2 = async (prompt: any[] = [], response_format = {

src/views/Editor/index3.vue

@@ -387,7 +387,7 @@ const setTitle = (newTitle: string) => {
   slidesStore.setTitle(newTitle)
 }
 
-setTitle2 = (newTitle: string) => {
+const setTitle2 = (newTitle: string) => {
   courseTitle.value = newTitle
   slidesStore.setTitle(newTitle)
   changeCourse()