diff --git a/server/age-os/agents/hldp-bus.js b/server/age-os/agents/hldp-bus.js
index abdca72d..1e8d9337 100644
--- a/server/age-os/agents/hldp-bus.js
+++ b/server/age-os/agents/hldp-bus.js
@@ -41,6 +41,7 @@ class HLDPBus {
     // ─── 消息队列（内存） ───
     this._queues = new Map();  // moduleId → [messages]
     this._handlers = new Map(); // msgType → [handler]
+    this._maxQueueSize = 1000; // 每个模块最多1000条待处理消息
 
     // ─── 广播订阅 ───
     this._subscribers = new Map(); // topic → Set(moduleId)
@@ -82,7 +83,15 @@ class HLDPBus {
     if (!this._queues.has(toModule)) {
       this._queues.set(toModule, []);
     }
-    this._queues.get(toModule).push(message);
+    const queue = this._queues.get(toModule);
+
+    // 队列大小限制：丢弃最旧的消息
+    if (queue.length >= this._maxQueueSize) {
+      queue.shift();
+      this.stats.totalFailed++;
+    }
+
+    queue.push(message);
 
     // 持久化
     await this._persistMessage(message);
diff --git a/server/age-os/agents/module-registry.js b/server/age-os/agents/module-registry.js
index 6a76d6c6..8bcf3f84 100644
--- a/server/age-os/agents/module-registry.js
+++ b/server/age-os/agents/module-registry.js
@@ -193,9 +193,8 @@ class ModuleRegistry {
         const sinceLastHeart = now - module.lastHeartbeatAt.getTime();
         if (sinceLastHeart > this._heartbeatTimeoutMs && module.status === 'alive') {
           console.warn(`[Registry] ${moduleId} 心跳超时 ${Math.round(sinceLastHeart / 1000)}秒`);
-          module.status = 'degraded';
 
-          // 尝试触发自诊断
+          // 通过模块自身的诊断方法更新状态
           try {
             await module.selfDiagnose();
           } catch (err) {
diff --git a/server/age-os/agents/sy-scan.js b/server/age-os/agents/sy-scan.js
index 109fa42c..1c7e0a67 100644
--- a/server/age-os/agents/sy-scan.js
+++ b/server/age-os/agents/sy-scan.js
@@ -98,7 +98,7 @@ class LivingSyScan extends LivingModule {
         // 尝试清理空目录
         try {
           await db.query(
-            "UPDATE brain_nodes SET status = 'archived' WHERE node_type = 'folder' AND status = 'active' AND id NOT IN (SELECT DISTINCT parent_id FROM brain_nodes WHERE parent_id IS NOT NULL AND status = 'active')"
+            "UPDATE brain_nodes bn SET status = 'archived' WHERE bn.node_type = 'folder' AND bn.status = 'active' AND NOT EXISTS (SELECT 1 FROM brain_nodes child WHERE child.parent_id = bn.id AND child.status = 'active')"
           );
           return { action: 'empty_folders_archived', success: true };
         } catch (err) {