重构代码，统一config配置

backend/app/agent/rag_initializer.py

@@ -0,0 +1,23 @@
+# app/rag_initializer.py
+from ..rag.tools import create_rag_tool_sync
+from rag_core import create_parent_retriever
+from ..logger import info, warning
+
+async def init_rag_tool(local_llm_creator):
+    """初始化 RAG 工具，失败返回 None"""
+    try:
+        info("🔄 正在初始化 RAG 检索系统...")
+        retriever = create_parent_retriever(
+            collection_name="rag_documents",
+            search_k=5,
+        )
+        rewrite_llm = local_llm_creator()
+        rag_tool = create_rag_tool_sync(
+            retriever, rewrite_llm,
+            num_queries=3, rerank_top_n=5
+        )
+        info("✅ RAG 检索工具初始化成功")
+        return rag_tool
+    except Exception as e:
+        warning(f"⚠️ RAG 检索工具初始化失败: {e}")
+        return None