修复重构后的导入错误和缺失模块

backend/app/main_graph/utils/rag_initializer.py

@@ -1,8 +1,8 @@
 # app/rag_initializer.py
-from ..rag.tools import create_rag_tool_sync
+from app.rag.tools import create_rag_tool_sync
 from rag_core import create_parent_retriever
-from ..model_services import get_embedding_service
-from ..logger import info, warning
+from app.model_services import get_embedding_service
+from app.logger import info, warning
 
 async def init_rag_tool(local_llm_creator):
     """初始化 RAG 工具，失败返回 None"""

backend/app/main_graph/utils/retry_utils.py

@@ -287,7 +287,7 @@ def create_retry_wrapper_for_node(
                 time.sleep(delay)
         
         # 所有重试都失败，更新状态错误信息
-        from .state import ErrorRecord, ErrorSeverity
+        from app.main_graph.state import ErrorRecord, ErrorSeverity
         
         error_record = ErrorRecord(
             error_type=f"{node_name}TimeoutError",

backend/app/main_graph/utils/subgraph_builder.py

@@ -6,7 +6,7 @@ Main Graph Builder - Full React Mode with Loop Reasoning
 from app.main_graph.graph import StateGraph, START, END
 from typing import Dict, Any
 
-from .state import MainGraphState, CurrentAction
+from app.main_graph.state import MainGraphState, CurrentAction
 from .react_nodes import (
     init_state_node,
     react_reason_node,
@@ -50,7 +50,7 @@ def wrap_subgraph_for_error_handling(subgraph, name: str):
             
         except Exception as e:
             # 捕获子图错误，传递给主图
-            from .state import ErrorRecord, ErrorSeverity
+            from app.main_graph.state import ErrorRecord, ErrorSeverity
             from datetime import datetime
             
             error_record = ErrorRecord(