fix: 回退muLock为简单版本，保留deadlock监控

backend/ai-core/internal/background/thinker.go

@@ -292,27 +292,31 @@ func timePeriod(now time.Time) (string, string) {
 // SetMessagePusher 设置主动消息推送回调
 // SetScheduleLoader sets the dynamic schedule loader for interval calculation.
 func (t *Thinker) SetScheduleLoader(loader *ScheduleLoader) {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	t.scheduleLoader = loader
 }
 
 func (t *Thinker) SetMessagePusher(pusher func(string, string, string)) {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	t.messagePusher = pusher
 }
 
 // SetPlatformMessagePusher sets the callback for pushing proactive messages to platform adapters (OBv11, etc.).
 func (t *Thinker) SetPlatformMessagePusher(pusher func(ProactiveTarget, string)) {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	t.platformMessagePusher = pusher
 }
 
 // SetBotUID sets the bot's own platform UID (e.g., OBv11 account).
 func (t *Thinker) SetBotUID(platform, uid string) {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	if t.botUIDs == nil {
 		t.botUIDs = make(map[string]string)
@@ -324,7 +328,8 @@ func (t *Thinker) SetBotUID(platform, uid string) {
 
 // AddOrUpdatePlatformChannel adds or updates a platform channel with resolved display name.
 func (t *Thinker) AddOrUpdatePlatformChannel(platform, channelType, channelID, channelName, adapterID, adapterName string) {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 
 	for i, ch := range t.platformChannels {
@@ -354,7 +359,8 @@ func (t *Thinker) AddOrUpdatePlatformChannel(platform, channelType, channelID, c
 
 // SetEmotionTracker sets the emotion tracker.
 func (t *Thinker) SetEmotionTracker(et *persona.EmotionTracker) {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	t.emotionTracker = et
 }
@@ -362,7 +368,8 @@ func (t *Thinker) SetEmotionTracker(et *persona.EmotionTracker) {
 // UpdatePresence updates the user online status.
 // Called by the ai-core presence endpoint when gateway detects connect/disconnect.
 func (t *Thinker) UpdatePresence(online bool, sessionID string) {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	wasOffline := !t.isUserOnline()
 	t.setUserOnline(online)
@@ -390,7 +397,8 @@ func (t *Thinker) UpdatePresence(online bool, sessionID string) {
 // TriggerReminderMessage pushes a reminder message generated by LLM to the user.
 // Called by the internal reminder-trigger endpoint when a reminder fires.
 func (t *Thinker) TriggerReminderMessage(userID, sessionID, message string) {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	pusher := t.messagePusher
 	pushSessionID := sessionID
@@ -410,7 +418,8 @@ func (t *Thinker) TriggerReminderMessage(userID, sessionID, message string) {
 
 // PushPlatformMessage pushes a message to a platform channel via the platform pusher.
 func (t *Thinker) PushPlatformMessage(target ProactiveTarget, message string) {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	pusher := t.platformMessagePusher
 
@@ -424,7 +433,8 @@ func (t *Thinker) PushPlatformMessage(target ProactiveTarget, message string) {
 
 // IsUserRecentlyActive returns true if the user has been active within the given duration.
 func (t *Thinker) IsUserRecentlyActive(d time.Duration) bool {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	return time.Since(t.lastUserTime()) < d
 }
@@ -557,7 +567,8 @@ func (t *Thinker) restoreContext() {
 		}
 	}
 	if !latest.IsZero() && time.Since(latest) < 24*time.Hour {
-		t.muLock()
+		if !t.muLock() {
+			return
 		defer t.muUnlock()
 		t.lastUserMessage = latest
 		t.setLastUser(latest)
@@ -672,7 +683,8 @@ func (t *Thinker) TriggerPostChatThink() {
 		return
 	}
 
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	canThink := time.Since(t.lastThinkTimeAtomic()) >= t.minThinkGap
 
@@ -742,7 +754,8 @@ func (t *Thinker) resetSilenceTimer() {
 			return
 		case <-t.silenceTimer.C:
 			// 再次检查：用户是否真的沉默了足够久
-			t.muLock()
+			if !t.muLock() {
+				return
 			defer t.muUnlock()
 			silenceDuration := time.Since(t.lastUserTime())
 			canThink := time.Since(t.lastThinkTimeAtomic()) >= t.minThinkGap
@@ -860,7 +873,8 @@ func (t *Thinker) performPlatformObservation() {
 	}
 
 	observationContent := fmt.Sprintf("[平台观察 %s]\n%s", time.Now().In(t.timeLocation).Format("15:04"), result.Summary)
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	t.pendingThoughts = append(t.pendingThoughts, &PendingThought{
 		Content:   observationContent,
@@ -893,7 +907,8 @@ func (t *Thinker) lightThinkLoop() {
 			log.Println("[后台思考] 轻量思考已停止")
 			return
 		case <-time.After(t.lightThinkInterval):
-			t.muLock()
+			if !t.muLock() {
+				return
 			defer t.muUnlock()
 			sinceLastUser := time.Since(t.lastUserTime())
 			sinceLastThink := time.Since(t.lastThinkTimeAtomic())
@@ -955,7 +970,8 @@ func (t *Thinker) performLightThink() {
 	// Check if deep think should be woken.
 	if strings.Contains(content, "【需要深思】") {
 		log.Println("[轻量思考] 检测到【需要深思】，唤醒深度思考...")
-		t.muLock()
+		if !t.muLock() {
+			return
 		defer t.muUnlock()
 		canDeep := time.Since(t.lastThinkTimeAtomic()) >= t.minThinkGap
 
@@ -971,7 +987,8 @@ func (t *Thinker) performLightThink() {
 		topic := strings.TrimSpace(content[idx+len("【话题发起】"):])
 		if topic != "" {
 			log.Printf("[轻量思考] 话题发起: %s", topic)
-			t.muLock()
+			if !t.muLock() {
+				return
 			defer t.muUnlock()
 			pusher := t.messagePusher
 			sessionID := t.activeSessionID
@@ -1049,7 +1066,8 @@ func (t *Thinker) periodicThinkLoop() {
 
 // GetPendingThoughts 获取并消费所有待处理的后台思考
 func (t *Thinker) GetPendingThoughts() []*PendingThought {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 
 	if len(t.pendingThoughts) == 0 {
@@ -1067,7 +1085,8 @@ func (t *Thinker) GetPendingThoughts() []*PendingThought {
 
 // HasPendingThoughts 检查是否有待处理的思考
 func (t *Thinker) HasPendingThoughts() bool {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	return len(t.pendingThoughts) > 0
 }
@@ -1079,7 +1098,8 @@ func (t *Thinker) HasPendingThoughts() bool {
 // 防御性速率限制：即使调用方未检查 minThinkGap，performThink 自身也会
 // 强制执行最小间隔，防止并发调用或 bug 导致 LLM 配额被快速消耗。
 func (t *Thinker) performThink(triggerReason string) {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	gapSinceLast := time.Since(t.lastThinkTimeAtomic())
 	minGap := t.minThinkGap
@@ -1100,14 +1120,16 @@ func (t *Thinker) performThink(triggerReason string) {
 
 	ctx, cancel := context.WithTimeout(context.Background(), 120*time.Second)
 	defer cancel()
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	t.thinkCancel = cancel
 
 
 	// 0. 让步于前台——如果用户最近有活动（非post_chat），跳过本次思考。
 	if triggerReason != "post_chat" {
-		t.muLock()
+		if !t.muLock() {
+			return
 		defer t.muUnlock()
 		sinceLastUser := time.Since(t.lastUserTime())
 
@@ -1121,7 +1143,8 @@ func (t *Thinker) performThink(triggerReason string) {
 
 	// 0. 让步于前台——如果用户最近有活动（非post_chat），跳过本次思考。
 	if triggerReason != "post_chat" {
-		t.muLock()
+		if !t.muLock() {
+			return
 		defer t.muUnlock()
 		sinceLastUser := time.Since(t.lastUserTime())
 
@@ -1141,7 +1164,8 @@ func (t *Thinker) performThink(triggerReason string) {
 	// 2. 获取当前活跃会话的对话历史（优先活跃会话，回退到管理员主会话）
 	var convHistory []model.LLMMessage
 	if t.convStore != nil {
-		t.muLock()
+		if !t.muLock() {
+			return
 		defer t.muUnlock()
 		sessionID := t.activeSessionID
 		if sessionID == "" {
@@ -1259,7 +1283,8 @@ func (t *Thinker) performThink(triggerReason string) {
 	// 4.5 获取最近平台观察（定期触发和对话后触发时注入）
 	var platformObservation string
 	if triggerReason == "periodic" || triggerReason == "post_chat" {
-		t.muLock()
+		if !t.muLock() {
+			return
 		defer t.muUnlock()
 		for i := len(t.pendingThoughts) - 1; i >= 0; i-- {
 			if strings.HasPrefix(t.pendingThoughts[i].Content, "[平台观察") {
@@ -1410,7 +1435,8 @@ func (t *Thinker) performThink(triggerReason string) {
 				if len(parts) == 2 {
 					adapterName, groupID := parts[0], parts[1]
 					// Find the channel to get the correct platform type.
-					t.muLock()
+					if !t.muLock() {
+						return
 					defer t.muUnlock()
 					var platform string
 					for _, ch := range t.platformChannels {
@@ -1664,7 +1690,8 @@ func (t *Thinker) buildThinkingUserPrompt(
 	case "post_chat":
 		sb.WriteString("刚有人和你聊完天。你想自然地在心里回味一下刚才的对话……\n")
 	case "silence":
-		t.muLock()
+		if !t.muLock() {
+			return
 		defer t.muUnlock()
 		silenceDuration := time.Since(t.lastUserTime())
 
@@ -1764,7 +1791,8 @@ func (t *Thinker) buildThinkingUserPrompt(
 		}
 
 		// OBv11 platform identity and available channels for proactive messaging.
-		t.muLock()
+		if !t.muLock() {
+			return
 		defer t.muUnlock()
 		qqChannels := t.platformChannels
 		botUIDs := t.botUIDs
@@ -1913,7 +1941,8 @@ func (t *Thinker) buildOpenAITools() []llm.OpenAITool {
 
 // storeThought 存储思考结果到待推送队列，并异步持久化到 memory-service
 func (t *Thinker) storeThought(content string, toolCallsJSON string, toolCallCount int) {
-	t.muLock()
+	if !t.muLock() {
+		return
 	defer t.muUnlock()
 	t.pendingThoughts = append(t.pendingThoughts, &PendingThought{
 		Content:   content,
@@ -2089,7 +2118,8 @@ func (t *Thinker) extractProactiveMessage(content string) (string, *ProactiveTar
 						channelID = "private_" + m[2]
 					}
 					adapterName := platform // fallback to format key
-					t.muLock()
+					if !t.muLock() {
+						return
 					defer t.muUnlock()
 					for _, ch := range t.platformChannels {
 						if ch.Platform == platform && ch.ChannelType == chatType && ch.ChannelID == channelID {
@@ -2681,7 +2711,8 @@ func (t *Thinker) setLastProactive(ts time.Time) { t.lastProactiveNs.Store(ts.Un
 func (t *Thinker) DeadlockDetected(timeout time.Duration) bool {
 	done := make(chan struct{})
 	go func() {
-		t.muLock()
+		if !t.muLock() {
+			return
 		defer t.muUnlock()
 
 		close(done)
@@ -2707,7 +2738,8 @@ func (t *Thinker) StartDeadlockMonitor() {
 		for range ticker.C {
 			done := make(chan struct{})
 			go func() {
-				t.muLock()
+				if !t.muLock() {
+					return
 				defer t.muUnlock()
 
 				close(done)