fix: 修复 RAG 无限循环问题和导入错误

主要修复：
1. 修复 RAG 推理无限循环问题（大小写不匹配 + 缺少已检索结果检查）
2. 修复 intent_classifier.py 的绝对导入错误
3. 删除旧的 start.sh 脚本，添加新的启动脚本
4. 优化路由逻辑和状态管理

tools/test/test_fast_rag_fix.py

@@ -0,0 +1,97 @@
+#!/usr/bin/env python3
+"""
+快速测试 - 测试 fast_rag 路径修复
+"""
+import sys
+import asyncio
+from pathlib import Path
+from dotenv import load_dotenv
+
+# 路径设置
+project_root = Path(__file__).resolve().parent.parent
+sys.path.insert(0, str(project_root))
+sys.path.insert(0, str(project_root / "backend"))
+load_dotenv(project_root / ".env")
+
+from app.main_graph.state import MainGraphState, CurrentAction
+from app.main_graph.utils.main_graph_builder import build_react_main_graph
+from app.model_services.chat_services import get_all_chat_services
+from app.main_graph.tools.graph_tools import AVAILABLE_TOOLS
+
+
+async def test_fast_rag_path():
+    """测试 fast_rag 路径"""
+    print("=" * 60)
+    print("测试 fast_rag 路径修复")
+    print("=" * 60)
+    
+    # 1. 获取 LLM
+    chat_services = get_all_chat_services()
+    if not chat_services:
+        print("✗ 没有可用的 LLM 服务")
+        return
+    
+    llm = list(chat_services.values())[0]
+    print(f"✓ 使用 LLM: {list(chat_services.keys())[0]}")
+    
+    # 2. 构建图
+    graph = build_react_main_graph(
+        llm=llm,
+        tools=AVAILABLE_TOOLS,
+        use_hybrid_router=True
+    ).compile()
+    print(f"✓ 图构建完成")
+    
+    # 3. 测试问题
+    test_query = "吕布和张飞谁厉害？"
+    print(f"\n测试问题: {test_query}")
+    
+    # 4. 创建状态
+    input_state = {
+        "user_query": test_query,
+        "messages": [{"role": "user", "content": test_query}],
+        "user_id": "test_user",
+        "current_action": CurrentAction.NONE
+    }
+    
+    # 5. 执行
+    print("开始执行...")
+    try:
+        result = await graph.ainvoke(
+            input_state,
+            config={"configurable": {"thread_id": "test_fast_rag"}}
+        )
+        
+        print(f"\n✓ 执行成功！")
+        print(f"最终回答: {result.get('final_result', '')[:300]}")
+        
+        # 调试信息
+        debug_info = result.get("debug_info", {})
+        print(f"\n调试信息:")
+        if "fast_path_failed" in debug_info:
+            print(f"  - fast_path_failed: {debug_info['fast_path_failed']}")
+        if "fast_path_fail_reason" in debug_info:
+            print(f"  - fast_path_fail_reason: {debug_info['fast_path_fail_reason']}")
+            
+    except Exception as e:
+        print(f"\n✗ 执行失败: {e}")
+        import traceback
+        print(traceback.format_exc())
+        return False
+    
+    return True
+
+
+async def main():
+    success = await test_fast_rag_path()
+    if success:
+        print("\n🎉 测试通过！")
+    else:
+        print("\n⚠️  测试失败")
+
+
+if __name__ == "__main__":
+    try:
+        asyncio.run(main())
+    except KeyboardInterrupt:
+        print("\n测试被中断")