兼容：同时注册新旧路径到 allowed_msgpack_modules

避免旧 checkpoint 反序列化时出现警告

backend/app/agent/agent_service.py

@@ -33,6 +33,7 @@ def create_serde() -> JsonPlusSerializer:
 
     return JsonPlusSerializer(
         allowed_msgpack_modules=[
+            # 新路径
             ("backend.app.core.intent", "ReasoningAction"),
             ("backend.app.core.intent", "RetrievalConfig"),
             ("backend.app.core.intent", "ReasoningResult"),
@@ -43,6 +44,17 @@ def create_serde() -> JsonPlusSerializer:
             ("backend.app.main_graph.state", "HybridRouterState"),
             ("backend.app.main_graph.state", "FastPathState"),
             ("backend.app.main_graph.nodes.hybrid_router", "HybridRouterResult"),
+            # 旧路径（兼容旧 checkpoint 数据）
+            ("app.core.intent", "ReasoningAction"),
+            ("app.core.intent", "RetrievalConfig"),
+            ("app.core.intent", "ReasoningResult"),
+            ("app.main_graph.state", "CurrentAction"),
+            ("app.main_graph.state", "ErrorSeverity"),
+            ("app.main_graph.state", "ErrorRecord"),
+            ("app.main_graph.state", "ReactReasoningState"),
+            ("app.main_graph.state", "HybridRouterState"),
+            ("app.main_graph.state", "FastPathState"),
+            ("app.main_graph.nodes.hybrid_router", "HybridRouterResult"),
         ]
     )