修复行为树关键bug

- 修复BehaviorTree.ts中lastOpenNodes的空指针风险
- 修复Ticker.ts中closeNode栈操作不对称问题
- 修复Agent.ts中subject参数传递错误

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/behaviortree/Agent.ts

@@ -25,7 +25,7 @@ export class Agent {
      * 执行
      */
     public tick(): void {
-        this.tree.tick(this, this.blackboard, this.ticker);
+        this.tree.tick(this.ticker.subject, this.blackboard, this.ticker);
         if (this.blackboard.interrupt) {
             this.blackboard.interrupt = false;
 

src/behaviortree/BehaviorTree.ts

@@ -32,7 +32,7 @@ export class BehaviorTree {
         ticker.openNodes.length = 0;
         this._root._execute(ticker);
         // 上次打开的节点
-        let lastOpenNodes = blackboard.get("openNodes", this._id) as BaseNode[];
+        let lastOpenNodes = (blackboard.get("openNodes", this._id) || []) as BaseNode[];
         // 当前打开的节点
         let currOpenNodes = ticker.openNodes;
         let start = 0;

src/behaviortree/Ticker.ts

@@ -44,7 +44,11 @@ export class Ticker {
      * @param node 节点
      */
     public closeNode(node: BaseNode): void {
-        this.openNodes.pop();
+        // 查找并移除指定节点，而不是简单地pop
+        const index = this.openNodes.lastIndexOf(node);
+        if (index !== -1) {
+            this.openNodes.splice(index, 1);
+        }
     }
 
     /**