feat: 新增 ExecutionCompleted 信号修复发送按钮状态

- 后端 OutboundEventKind/WsOutbound 新增 ExecutionCompleted 变体
- processor 在 handle_message 完成后发送该信号
- 飞书/微信通道过滤该信号（不发送）
- 前端 useChat 移除 stream_delta/assistant_response 的 isLoading=false
- 改由 execution_completed 事件统一设置 isLoading=false，确保智能体迭代期间按钮保持停止态

src/bus/message.rs

@@ -425,6 +425,8 @@ pub enum OutboundEventKind {
     StreamDelta,
     /// 流式结束信号
     StreamEnd,
+    /// 智能体执行完全结束（不再有后续工具调用或 LLM 迭代）
+    ExecutionCompleted,
 }
 
 impl OutboundMessage {
@@ -630,6 +632,31 @@ impl OutboundMessage {
         }
     }
 
+    /// 构造执行完成信号
+    pub fn execution_completed(
+        channel: impl Into<String>,
+        chat_id: impl Into<String>,
+        session_id: Option<String>,
+        metadata: HashMap<String, String>,
+    ) -> Self {
+        Self {
+            channel: channel.into(),
+            chat_id: chat_id.into(),
+            session_id,
+            content: String::new(),
+            reply_to: None,
+            media: Vec::new(),
+            metadata,
+            event_kind: OutboundEventKind::ExecutionCompleted,
+            role: "assistant".to_string(),
+            tool_call_id: None,
+            tool_name: None,
+            tool_arguments: None,
+            reasoning_content: None,
+            message_id: None,
+        }
+    }
+
     pub fn from_chat_message(
         channel: &str,
         chat_id: &str,

src/channels/feishu.rs

@@ -2461,7 +2461,7 @@ impl Channel for FeishuChannel {
     }
 
     async fn send(&self, msg: OutboundMessage) -> Result<(), ChannelError> {
-        if matches!(msg.event_kind, OutboundEventKind::ToolResult | OutboundEventKind::ToolPending | OutboundEventKind::StreamDelta | OutboundEventKind::StreamEnd)
+        if matches!(msg.event_kind, OutboundEventKind::ToolResult | OutboundEventKind::ToolPending | OutboundEventKind::StreamDelta | OutboundEventKind::StreamEnd | OutboundEventKind::ExecutionCompleted)
             || msg.metadata.get("is_subagent_event").map(|v| v == "true").unwrap_or(false)
         {
             return Ok(());

src/channels/wechat.rs

@@ -315,6 +315,7 @@ impl Channel for WechatChannel {
                 | OutboundEventKind::ToolCall
                 | OutboundEventKind::StreamDelta
                 | OutboundEventKind::StreamEnd
+                | OutboundEventKind::ExecutionCompleted
         ) || msg.metadata.get("is_subagent_event").map(|v| v == "true").unwrap_or(false)
         {
             return Ok(());

src/gateway/processor.rs

@@ -387,6 +387,25 @@ impl InboundProcessor {
             self.cancel_manager.remove_by_topic(topic_id).await;
         }
 
+        // 发送执行完成信号，通知前端可以停止 loading 状态
+        // 无论成功还是失败都发送，确保前端状态正确
+        let mut completion_metadata = inbound.forwarded_metadata.clone();
+        if let Some(ref topic_id) = current_topic {
+            completion_metadata.insert("topic_id".to_string(), topic_id.clone());
+        }
+        if let Err(error) = self
+            .bus
+            .publish_outbound(OutboundMessage::execution_completed(
+                channel,
+                chat_id,
+                Some(session_id),
+                completion_metadata,
+            ))
+            .await
+        {
+            tracing::error!(error = %error, "Failed to publish execution_completed");
+        }
+
         Ok(())
     }
 }

src/protocol/mod.rs

@@ -295,6 +295,13 @@ pub enum WsOutbound {
         #[serde(default, skip_serializing_if = "Option::is_none")]
         topic_id: Option<String>,
     },
+    #[serde(rename = "execution_completed")]
+    ExecutionCompleted {
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        topic_id: Option<String>,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        timestamp: Option<i64>,
+    },
     #[serde(rename = "todo_list")]
     TodoList {
         todos: Vec<TodoItemSummary>,

src/protocol/ws_adapter.rs

@@ -194,6 +194,10 @@ pub(crate) fn ws_outbound_from_outbound_message(message: &OutboundMessage) -> Ve
             subagent_task_id: message.metadata.get("subagent_task_id").cloned(),
             topic_id: message.metadata.get("topic_id").cloned(),
         }],
+        OutboundEventKind::ExecutionCompleted => vec![WsOutbound::ExecutionCompleted {
+            topic_id: message.metadata.get("topic_id").cloned(),
+            timestamp: Some(crate::protocol::now_timestamp()),
+        }],
     }
 }
 

web/src/hooks/useChat.ts

@@ -29,6 +29,7 @@ import type {
   ChannelList,
   StreamDelta,
   StreamEnd,
+  ExecutionCompleted,
   WsInbound,
 } from '../types/protocol'
 
@@ -658,7 +659,7 @@ export function useChat(): UseChatReturn {
             },
           ]
         })
-        setIsLoading(false)
+        // 注意：stream_delta 期间不设置 isLoading=false，智能体仍在生成
         if (msg.user_message_id) applyUserMessageId(msg.user_message_id)
         break
       }
@@ -668,6 +669,15 @@ export function useChat(): UseChatReturn {
         break
       }
 
+      case 'execution_completed': {
+        // 智能体执行完全结束（不再有后续工具调用或 LLM 迭代）
+        const msg = message as ExecutionCompleted
+        // 按 topic_id 隔离：只处理当前话题的完成信号
+        if (msg.topic_id && msg.topic_id !== selectedTopicRef.current) return
+        setIsLoading(false)
+        break
+      }
+
       case 'assistant_response': {
         const msg = message as AssistantResponse
         // 按 topic_id 隔离：如果消息属于其他话题则丢弃
@@ -692,7 +702,7 @@ export function useChat(): UseChatReturn {
           }
           return [...prev, newMsg]
         })
-        setIsLoading(false)
+        // 注意：assistant_response 不设置 isLoading=false，智能体可能还会调用工具继续迭代
 
         // 当前话题无描述时，可能刚触发了异步生成，标记需要刷新
         const currentTopic = topicsRef.current.find(t => t.id === selectedTopicRef.current)

web/src/types/protocol.ts

@@ -278,6 +278,12 @@ export interface StreamEnd {
   topic_id?: string
 }
 
+export interface ExecutionCompleted {
+  type: 'execution_completed'
+  topic_id?: string
+  timestamp?: number
+}
+
 export type WsOutbound =
   | AssistantResponse
   | ToolCall
@@ -287,6 +293,7 @@ export type WsOutbound =
   | TaskStarted
   | StreamDelta
   | StreamEnd
+  | ExecutionCompleted
   | SessionEstablished
   | SessionCreated
   | SessionList