fix(前端): 优化对话保持逻辑并增加错误处理

- 将重新激活逻辑从 activeInteractionMode 改为更可靠的 startChat
- 增加对 startChat 失败情况的处理，包括错误码 999400004 的特殊处理
- 添加双重错误处理机制，在 startChat 失败后尝试 activeInteractionMode
- 将保持活跃间隔从 20000 毫秒缩短为 10000 毫秒
- 移除重复的 updateUIState 调用

frontend/scripts/main.js

@@ -268,25 +268,46 @@ const eventListeners = {
         logger.info('任务已结束，正在自动重新激活...', data);
         state.isChatting = false;
         state.jobInfo = null;
+        updateUIState();
         if (state.keepAliveActive) {
             setTimeout(async () => {
                 try {
-                    logger.info('正在调用 activeInteractionMode...');
-                    await HwICSUiSdk.activeInteractionMode();
-                    logger.info('自动激活成功');
-                    state.isChatting = true;
-                    updateUIState();
+                    logger.info('正在调用 startChat 重新开始对话...');
+                    const chatResult = await HwICSUiSdk.startChat({
+                        interactionMode: InteractionMode.AUDIO,
+                        wakeupType: WakeupType.VOICE,
+                        preCheckPermissions: false
+                    });
+                    if (chatResult.result) {
+                        logger.info('重新开始对话成功', chatResult);
+                        state.isChatting = true;
+                        updateUIState();
+                    } else {
+                        logger.warn('重新开始对话返回失败', chatResult);
+                        if (chatResult.errorCode === '999400004') {
+                            logger.info('对话已存在，尝试 activeInteractionMode');
+                            await HwICSUiSdk.activeInteractionMode();
+                            state.isChatting = true;
+                            updateUIState();
+                        }
+                    }
                 } catch (error) {
-                    logger.error('自动激活失败', error);
+                    logger.error('重新激活失败', error);
+                    try {
+                        await HwICSUiSdk.activeInteractionMode();
+                        state.isChatting = true;
+                        updateUIState();
+                    } catch (e) {
+                        logger.error('activeInteractionMode 也失败', e);
+                    }
                 }
-            }, 1000);
+            }, 2000);
         }
-        updateUIState();
     }
 };
 
 let keepAliveTimer = null;
-const KEEP_ALIVE_INTERVAL = 20000;
+const KEEP_ALIVE_INTERVAL = 10000;
 
 function startKeepAlive() {
     if (keepAliveTimer) return;