修复 AI 助手缺少 http 导入问题

添加 import { http } from '@/utils/request'
解决 AI 接口调用失败的问题。

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/views/ai-chat/index.vue

@@ -104,6 +104,7 @@ import { ref, nextTick, onMounted } from 'vue'
 import { ElMessage } from 'element-plus'
 import { ChatDotRound, Delete, Download, Promotion } from '@element-plus/icons-vue'
 import { useUserStore } from '@/store/user'
+import { http } from '@/utils/request'
 
 interface Message {
   role: 'user' | 'assistant'