feat：添加频率精准控制，移除s4u代码，优化tool返回值

src/chat/replyer/private_generator.py

@@ -7,7 +7,6 @@ import re
 from typing import List, Optional, Dict, Any, Tuple
 from datetime import datetime
 from src.memory_system.Memory_chest import global_memory_chest
-from src.mais4u.mai_think import mai_thinking_manager
 from src.common.logger import get_logger
 from src.common.data_models.database_data_model import DatabaseMessages
 from src.common.data_models.info_data_model import ActionPlannerInfo