改进与新的文件格式

src/heurams/kernel/particles/nucleon.py

@@ -1,13 +1,15 @@
 class Nucleon:
     """原子核: 材料元数据"""
 
-    def __init__(self, ident: str, payload: dict):
+    def __init__(self, ident: str, payload: dict, metadata: dict = {}):
         """初始化原子核 (记忆内容)
 
         Args:
             ident: 唯一标识符
             payload: 记忆内容信息
+            metadata: 可选元数据信息
         """
+        self.metadata = metadata
         self.payload = payload
         self.ident = ident