修复循环推理bug

backend/app/main_graph/nodes/reasoning.py

@@ -0,0 +1,68 @@
+"""
+React 推理节点
+使用 intent.py 进行意图推理
+"""
+
+from typing import Dict, Any, Optional
+from datetime import datetime
+
+from app.core.intent import react_reason_async, ReasoningResult
+from app.main_graph.state import MainGraphState
+from app.logger import info
+from ._utils import dispatch_custom_event, make_react_event
+
+
+async def react_reason_node(state: MainGraphState, config: Optional[Dict[str, Any]] = None) -> MainGraphState:
+    """React 模式推理节点：判断下一步做什么"""
+    state.current_phase = "react_reasoning"
+    state.reasoning_step += 1
+
+    info(f"[推理] 第 {state.reasoning_step} 次推理开始")
+
+    # 步骤1: 准备上下文
+    context = {
+        "retrieved_docs": state.rag_docs,
+        "previous_actions": [h.get("action") for h in state.reasoning_history],
+        "reasoning_history": state.reasoning_history,
+        "messages": state.messages,
+        "errors": state.errors
+    }
+
+    # 步骤2: 执行推理
+    result: ReasoningResult = await react_reason_async(state.user_query, context)
+
+    info(f"[推理] 推理结果: action={result.action.name}, confidence={result.confidence}")
+    if result.reasoning:
+        info(f"[推理] 推理过程: {result.reasoning}")
+
+    # 步骤3: 记录推理历史
+    state.reasoning_history.append({
+        "step": state.reasoning_step,
+        "action": result.action.name,
+        "confidence": result.confidence,
+        "reasoning": result.reasoning,
+        "timestamp": datetime.now().isoformat()
+    })
+
+    # 步骤4: 更新调试信息
+    state.debug_info["last_reasoning"] = {
+        "action": result.action.name,
+        "confidence": result.confidence,
+        "reasoning": result.reasoning
+    }
+    state.debug_info["reasoning_result"] = result
+    state.last_action = result.action.name
+
+    # 步骤5: 发送推理事件
+    await dispatch_custom_event(
+        "react_reasoning",
+        make_react_event(
+            state.reasoning_step,
+            result.action.name,
+            result.confidence,
+            result.reasoning
+        ),
+        config
+    )
+
+    return state