修复循环推理bug

backend/app/main_graph/nodes/_utils.py

@@ -0,0 +1,57 @@
+"""
+主图节点通用工具模块
+包含事件发送、状态更新等通用功能
+"""
+
+from typing import Dict, Any, Optional
+
+
+async def dispatch_custom_event(
+    event_name: str,
+    data: Dict[str, Any],
+    config: Optional[Dict[str, Any]] = None,
+) -> None:
+    """
+    安全地发送自定义事件，忽略发送失败
+
+    Args:
+        event_name: 事件名称
+        data: 事件数据
+        config: LangChain 配置
+    """
+    if not config:
+        return
+    try:
+        from langchain_core.callbacks.manager import adispatch_custom_event
+        callbacks = config.get("callbacks")
+        if callbacks:
+            await adispatch_custom_event(event_name, data, callbacks=callbacks)
+    except Exception:
+        # 事件发送失败不应中断主流程
+        pass
+
+
+def make_react_event(
+    step: int,
+    action: str,
+    confidence: float = 1.0,
+    reasoning: str = ""
+) -> Dict[str, Any]:
+    """
+    构造标准推理事件数据
+
+    Args:
+        step: 当前步数
+        action: 动作名称
+        confidence: 置信度
+        reasoning: 推理过程
+
+    Returns:
+        事件数据字典
+    """
+    return {
+        "step": step,
+        "action": action,
+        "confidence": confidence,
+        "reasoning": reasoning
+    }