fix: 修复轮询机制下对话标题不自动更新的问题

- 后端：在标题生成后将 conversation_changed 事件添加到任务事件流
- 前端：在 taskPolling 中添加 conversation_changed 事件处理
- 前端：同步更新当前对话标题和对话列表中的标题
- 兼容：保留 WebSocket 的标题更新逻辑以向后兼容

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

server/chat_flow_helpers.py

@@ -73,6 +73,25 @@ def generate_conversation_title_background(
         if not ok:
             return
 
+        # 添加标题更新事件到任务事件流（用于轮询机制）
+        try:
+            from server.tasks import task_manager
+            tasks = task_manager.list_tasks(username)
+            running_task = None
+            for task in tasks:
+                if task.status == "running" and getattr(task, "conversation_id", None) == conversation_id:
+                    running_task = task
+                    break
+
+            if running_task:
+                task_manager._append_event(
+                    running_task,
+                    'conversation_changed',
+                    {'conversation_id': conversation_id, 'title': safe_title}
+                )
+        except Exception as exc:
+            debug_logger(f"[TitleGen] 添加任务事件失败: {exc}")
+
         try:
             socketio_instance.emit(
                 'conversation_changed',

static/src/app/methods/taskPolling.ts

@@ -116,6 +116,10 @@ export const taskPollingMethods = {
                 this.handleTokenUpdate(eventData, eventIdx);
                 break;
 
+            case 'conversation_changed':
+                this.handleConversationChanged(eventData, eventIdx);
+                break;
+
             case 'conversation_resolved':
                 this.handleConversationResolved(eventData, eventIdx);
                 break;
@@ -665,6 +669,29 @@ export const taskPollingMethods = {
         }
     },
 
+    handleConversationChanged(data: any, eventIdx: number) {
+        debugLog('[TaskPolling] 对话标题已更新, idx:', eventIdx, data);
+
+        if (data && data.conversation_id === this.currentConversationId) {
+            // 更新当前对话标题
+            if (data.title) {
+                this.currentConversationTitle = data.title;
+                debugLog('[TaskPolling] 更新当前对话标题:', data.title);
+            }
+
+            // 更新对话列表中的标题
+            if (data.title && Array.isArray(this.conversations)) {
+                const conv = this.conversations.find(c => c && c.id === data.conversation_id);
+                if (conv) {
+                    conv.title = data.title;
+                    debugLog('[TaskPolling] 更新对话列表中的标题:', data.title);
+                }
+            }
+
+            this.$forceUpdate();
+        }
+    },
+
     handleConversationResolved(data: any) {
         if (data && data.conversation_id) {
             this.currentConversationId = data.conversation_id;

static/src/composables/useLegacySocket.ts

@@ -763,6 +763,15 @@ export async function initializeLegacySocket(ctx: any) {
             if (ctx.initialRouteResolved) {
                 ctx.currentConversationId = data.conversation_id;
                 ctx.currentConversationTitle = data.title || '';
+
+                // 更新对话列表中的标题
+                if (data.title && Array.isArray(ctx.conversations)) {
+                    const conv = ctx.conversations.find(c => c && c.id === data.conversation_id);
+                    if (conv) {
+                        conv.title = data.title;
+                    }
+                }
+
                 ctx.promoteConversationToTop(data.conversation_id);
 
                 if (data.cleared) {