fix(docs): update WeCom AI Bot timeout duration in README and improve streamTask comments

docs/channels/wecom/wecom_aibot/README.zh.md

@@ -75,9 +75,9 @@ PicoClaw 立即返回 {finish: false}（Agent 开始处理）
   └─ Agent 完成 → 返回 {finish: true, content: "回答内容"}
 ```
 
-**超时处理**（任务超过 5 分 30 秒）：
+**超时处理**（任务超过 30 秒）：
 
-若 Agent 处理时间超过约 5 分 30 秒（企业微信最大轮询窗口为 6 分钟），PicoClaw 会：
+若 Agent 处理时间超过约 30 秒（企业微信最大轮询窗口为 6 分钟），PicoClaw 会：
 
 1. 立即关闭流，向用户显示「⏳ 正在处理中，请稍候，结果将稍后发送。」
 2. Agent 继续在后台运行

pkg/channels/wecom/aibot.go

@@ -37,21 +37,28 @@ type WeComAIBotChannel struct {
 	taskMu      sync.RWMutex
 }
 
-// streamTask represents a streaming task for AI Bot
+// streamTask represents a streaming task for AI Bot.
+//
+// Mutable fields (Finished, StreamClosed, StreamClosedAt) must be read/written
+// while holding WeComAIBotChannel.taskMu. Immutable fields (StreamID, ChatID,
+// ResponseURL, Question, CreatedTime, Deadline, answerCh, ctx, cancel) are set
+// once at creation and never modified, so they are safe to read without a lock.
 type streamTask struct {
-	StreamID       string
-	ChatID         string // used by Send() to find this task
-	ResponseURL    string // temporary URL for proactive reply (valid 1 hour, use once)
-	Question       string
-	CreatedTime    time.Time
-	Deadline       time.Time // ~30s, we close the stream here and switch to response_url
+	// immutable after creation
+	StreamID    string
+	ChatID      string // used by Send() to find this task
+	ResponseURL string // temporary URL for proactive reply (valid 1 hour, use once)
+	Question    string
+	CreatedTime time.Time
+	Deadline    time.Time          // ~30s, we close the stream here and switch to response_url
+	answerCh    chan string        // receives agent reply from Send()
+	ctx         context.Context    // canceled when task is removed; used to interrupt the agent goroutine
+	cancel      context.CancelFunc // call on task removal to cancel ctx
+
+	// mutable — guarded by WeComAIBotChannel.taskMu
 	StreamClosed   bool      // stream returned finish:true; waiting for agent to reply via response_url
 	StreamClosedAt time.Time // set when StreamClosed becomes true; used for accelerated cleanup
 	Finished       bool      // fully done
-	mu             sync.Mutex
-	answerCh       chan string        // receives agent reply from Send()
-	ctx            context.Context    // canceled when task is removed; used to interrupt the agent goroutine
-	cancel         context.CancelFunc // call on task removal to cancel ctx
 }
 
 // WeComAIBotMessage represents the decrypted JSON message from WeCom AI Bot
@@ -194,8 +201,13 @@ func (c *WeComAIBotChannel) Send(ctx context.Context, msg bus.OutboundMessage) e
 	}
 	c.chatTasks[msg.ChatID] = queue
 	var task *streamTask
+	var streamClosed bool
+	var responseURL string
 	if len(queue) > 0 {
 		task = queue[0]
+		// Read mutable fields while holding c.taskMu to avoid data races.
+		streamClosed = task.StreamClosed
+		responseURL = task.ResponseURL
 	}
 	c.taskMu.Unlock()
 
@@ -210,13 +222,9 @@ func (c *WeComAIBotChannel) Send(ctx context.Context, msg bus.OutboundMessage) e
 		return nil
 	}
 
-	task.mu.Lock()
-	streamClosed := task.StreamClosed
-	responseURL := task.ResponseURL
-	task.mu.Unlock()
-
 	if streamClosed {
 		// Stream already ended with a "please wait" notice; send the real reply via response_url.
+		// Note: task.StreamID and task.ChatID are immutable, safe to read without a lock.
 		logger.InfoCF("wecom_aibot", "Sending reply via response_url", map[string]any{
 			"stream_id": task.StreamID,
 			"chat_id":   msg.ChatID,
@@ -779,13 +787,11 @@ func (c *WeComAIBotChannel) getStreamResponse(task *streamTask, timestamp, nonce
 		// Normal finish: remove from all maps.
 		c.removeTask(task)
 	} else if closeStreamOnly {
-		// Only mark stream as closed; keep in chatTasks for Send() to find.
-		task.mu.Lock()
+		// Mark stream as closed and remove from streamTasks under a single lock
+		// to keep StreamClosed/StreamClosedAt consistent with map membership.
+		c.taskMu.Lock()
 		task.StreamClosed = true
 		task.StreamClosedAt = time.Now()
-		task.mu.Unlock()
-		// Remove from streamTasks (no more stream polls expected).
-		c.taskMu.Lock()
 		delete(c.streamTasks, task.StreamID)
 		c.taskMu.Unlock()
 	}
@@ -816,12 +822,12 @@ func (c *WeComAIBotChannel) getStreamResponse(task *streamTask, timestamp, nonce
 // removeTask removes a task from both streamTasks and chatTasks, marks it finished,
 // and cancels its context to interrupt the associated agent goroutine.
 func (c *WeComAIBotChannel) removeTask(task *streamTask) {
-	task.mu.Lock()
-	task.Finished = true
-	task.mu.Unlock()
-	task.cancel() // interrupt agent goroutine bound to this task
+	// Cancel first so the agent goroutine stops as soon as possible,
+	// before we acquire the write lock.
+	task.cancel()
 
 	c.taskMu.Lock()
+	task.Finished = true // written under c.taskMu, consistent with all readers
 	delete(c.streamTasks, task.StreamID)
 	queue := c.chatTasks[task.ChatID]
 	for i, t := range queue {