discard adjustable models' id prefix & payload length

app/models/base.py

@@ -56,22 +56,24 @@ class AutoID:
     不再需要手动定义任何 prefix，全自动根据 __tablename__ 编码生成
     支持子类自定义长度
     """
-    # 默认配置
-    _id_prefix_len = 3   # 前缀长度
-    _id_payload_len = 22 # 主体长度
+    # 全局固定配置
+    ID_PREFIX_LEN = 3
+    ID_PAYLOAD_LEN = 22
     
     @classmethod
     def id_length(cls) -> int:
         """返回当前类 ID 的总长度"""
-        return cls._id_prefix_len + cls._id_payload_len
+        return cls.ID_PREFIX_LEN + cls.ID_PAYLOAD_LEN
     
     @declared_attr
     def id(cls):
         # 运行时动态获取子类的 __tablename__
         tablename = cls.__tablename__
+        
         # 获取子类配置的长度
-        p_len = cls._id_prefix_len
-        s_len = cls._id_payload_len
+        p_len = AutoID.ID_PREFIX_LEN
+        s_len = AutoID.ID_PAYLOAD_LEN
+
         prefix = encode_tablename_to_prefix(tablename, length=p_len)
         
         # 核心工厂函数：拼接【编码后的表前缀】和【递增Payload】