添加rag置信度判断

backend/app/main_graph/nodes/routing.py

@@ -10,9 +10,9 @@
 
 from datetime import datetime
 
-from ...core.intent import get_route_by_reasoning, ReasoningAction
+from backend.app.core.intent import get_route_by_reasoning, ReasoningAction
 from ...main_graph.state import MainGraphState
-from ...logger import info
+from backend.app.logger import info
 
 
 # ========== 初始化状态节点 ==========
@@ -97,6 +97,12 @@ def route_by_reasoning(state: MainGraphState) -> str:
     }
     target = route_mapping.get(route, "llm_call")
 
+    # ========== RAG 次数硬限制 ==========
+    rag_attempts = getattr(state, 'rag_attempts', 0)
+    if target == "rag_retrieve" and rag_attempts >= 2:
+        info(f"[条件路由] RAG已尝试{rag_attempts}次，强制走联网搜索")
+        target = "web_search"
+
     # ========== 循环防护检测 ==========
     # 1. 路由模式检测（A→B→A→B 交替）
     if len(previous_actions) >= 4: