修复：更新 msgpack 序列化配置，加入新的类型

修复问题：
1. 更新模块路径从 "app.core.intent" 到 "backend.app.core.intent"
2. 添加新的状态类型：
   - ReactReasoningState
   - HybridRouterState
   - FastPathState
3. 添加 HybridRouterResult

backend/app/agent/agent_service.py

@@ -25,15 +25,24 @@ from ..main_graph.state import MainGraphState, CurrentAction
 def create_serde() -> JsonPlusSerializer:
     """创建带自定义类型注册的序列化器"""
     from backend.app.core.intent import ReasoningAction, RetrievalConfig, ReasoningResult
+    from backend.app.main_graph.state import (
+        CurrentAction, ErrorSeverity, ErrorRecord,
+        ReactReasoningState, HybridRouterState, FastPathState
+    )
+    from backend.app.main_graph.nodes.hybrid_router import HybridRouterResult
 
     return JsonPlusSerializer(
         allowed_msgpack_modules=[
-            ("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"),
+            ("backend.app.core.intent", "ReasoningAction"),
+            ("backend.app.core.intent", "RetrievalConfig"),
+            ("backend.app.core.intent", "ReasoningResult"),
+            ("backend.app.main_graph.state", "CurrentAction"),
+            ("backend.app.main_graph.state", "ErrorSeverity"),
+            ("backend.app.main_graph.state", "ErrorRecord"),
+            ("backend.app.main_graph.state", "ReactReasoningState"),
+            ("backend.app.main_graph.state", "HybridRouterState"),
+            ("backend.app.main_graph.state", "FastPathState"),
+            ("backend.app.main_graph.nodes.hybrid_router", "HybridRouterResult"),
         ]
     )