feat(chat): 增强对话中断处理，优化用户体验

- 在 chat_agent 函数中添加对客户端主动中断连接的处理，尝试保存已生成的部分内容
- 更新前端 AgentChatComponent.vue，新增发送或中断功能，确保用户可以中断对话生成并刷新消息历史
- 优化状态处理，确保中断状态下的消息历史刷新逻辑正常工作

server/routers/chat_router.py

@@ -322,6 +322,26 @@ async def chat_agent(
                     conv_mgr=conv_manager,
                     config_dict=langgraph_config,
                 )
+        except (asyncio.CancelledError, ConnectionError) as e:
+            # 客户端主动中断连接，尝试保存已生成的部分内容
+            logger.info(f"Client disconnected for thread {thread_id}: {e}")
+            try:
+                if conversation:
+                    langgraph_config = {"configurable": {"thread_id": thread_id, "user_id": user_id}}
+                    await save_messages_from_langgraph_state(
+                        agent_instance=agent,
+                        conversation=conversation,
+                        conv_mgr=conv_manager,
+                        config_dict=langgraph_config,
+                    )
+            except Exception as save_error:
+                logger.error(f"Error saving partial messages after disconnect: {save_error}")
+            # 通知前端中断（可能发送不到，但用于一致性）
+            try:
+                yield make_chunk(status="interrupted", message="对话已中断", meta=meta)
+            except Exception:
+                pass
+            return
         except Exception as e:
             logger.error(f"Error streaming messages: {e}, {traceback.format_exc()}")
             yield make_chunk(message=f"Error streaming messages: {e}", status="error")

web/src/components/AgentChatComponent.vue

@@ -71,9 +71,9 @@
             v-model="userInput"
             :is-loading="isProcessing"
             :disabled="!currentAgent"
-            :send-button-disabled="!userInput || !currentAgent || isProcessing"
+            :send-button-disabled="(!userInput || !currentAgent) && !isProcessing"
             :placeholder="'输入问题...'"
-            @send="handleSendMessage"
+            @send="handleSendOrStop"
             @keydown="handleKeyDown"
           />
 
@@ -131,9 +131,9 @@
             v-model="userInput"
             :is-loading="isProcessing"
             :disabled="!currentAgent"
-            :send-button-disabled="!userInput || !currentAgent || isProcessing"
+            :send-button-disabled="(!userInput || !currentAgent) && !isProcessing"
             :placeholder="'输入问题...'"
-            @send="handleSendMessage"
+            @send="handleSendOrStop"
             @keydown="handleKeyDown"
           />
           <div class="bottom-actions">
@@ -416,6 +416,11 @@ const _processStreamChunk = (chunk, threadId) => {
           fetchThreadMessages({ agentId: currentAgentId.value, threadId: threadId });
           resetOnGoingConv(threadId);
           break;
+    case 'interrupted':
+          // 中断状态，刷新消息历史
+          fetchThreadMessages({ agentId: currentAgentId.value, threadId: threadId });
+          resetOnGoingConv(threadId);
+          break;
   }
 };
 
@@ -726,6 +731,27 @@ const handleSendMessage = async () => {
   }
 };
 
+// 发送或中断
+const handleSendOrStop = async () => {
+  const threadId = currentChatId.value;
+  const threadState = getThreadState(threadId);
+  if (isProcessing.value && threadState && threadState.streamAbortController) {
+    // 中断生成
+    threadState.streamAbortController.abort();
+
+    // 中断后刷新消息历史，确保显示最新的状态
+    try {
+      await fetchThreadMessages({ agentId: currentAgentId.value, threadId: threadId });
+      message.info('已中断对话生成');
+    } catch (error) {
+      console.error('刷新消息历史失败:', error);
+      message.info('已中断对话生成');
+    }
+    return;
+  }
+  await handleSendMessage();
+};
+
 // ==================== UI HANDLERS ====================
 const handleRenameChat = () => {
   if (!currentChatId.value || !currentThread.value) {