feat(保活机制): 添加对话保活功能以维持交互状态

实现自动重新激活交互模式的功能，当任务结束时若保活激活则自动重新连接
添加定时保活ping机制，定期激活交互模式防止连接断开
在SDK初始化和销毁时自动管理保活定时器

frontend/scripts/main.js

@@ -43,7 +43,8 @@ const state = {
     isSpeaking: false,
     isMuted: false,
     jobInfo: null,
-    currentInteractionMode: InteractionMode.AUDIO
+    currentInteractionMode: InteractionMode.AUDIO,
+    keepAliveActive: false
 };
 
 const elements = {
@@ -256,14 +257,54 @@ const eventListeners = {
     },
 
     [ICSEventKey.JOB_END]: (data) => {
-        logger.info('任务已结束', data);
+        logger.info('任务已结束，正在自动重新激活...', data);
         state.isChatting = false;
         state.jobInfo = null;
-        updateConnectionStatus(false);
+        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();
+                } catch (error) {
+                    logger.error('自动激活失败', error);
+                }
+            }, 1000);
+        }
         updateUIState();
     }
 };
 
+let keepAliveTimer = null;
+const KEEP_ALIVE_INTERVAL = 30000;
+
+function startKeepAlive() {
+    if (keepAliveTimer) return;
+    state.keepAliveActive = true;
+    logger.info('启动对话保活机制');
+    keepAliveTimer = setInterval(async () => {
+        if (state.isInitialized && state.keepAliveActive) {
+            try {
+                await HwICSUiSdk.activeInteractionMode();
+                logger.debug('保活 ping');
+            } catch (error) {
+                logger.warn('保活失败', error);
+            }
+        }
+    }, KEEP_ALIVE_INTERVAL);
+}
+
+function stopKeepAlive() {
+    if (keepAliveTimer) {
+        clearInterval(keepAliveTimer);
+        keepAliveTimer = null;
+    }
+    state.keepAliveActive = false;
+    logger.info('停止对话保活机制');
+}
+
 function updateUIState() {
     const { isInitialized } = state;
 
@@ -442,6 +483,7 @@ async function initializeSDK() {
         fullscreenState.sdkInitialized = true;
         updateConnectionStatus(true);
         updateUIState();
+        startKeepAlive();
 
         elements.sdkVersion.textContent = `v${HwICSUiSdk.version}`;
 
@@ -468,6 +510,7 @@ async function destroySDK() {
         state.isSpeaking = false;
         state.jobInfo = null;
         fullscreenState.sdkInitialized = false;
+        stopKeepAlive();
 
         updateConnectionStatus(false);
         updateUIState();
@@ -1284,6 +1327,7 @@ function bindEvents() {
 
     window.addEventListener('beforeunload', () => {
         if (state.isInitialized) {
+            stopKeepAlive();
             HwICSUiSdk.destroy();
         }
     });