Fix import error and add source_files to config

foundation_bert.py

@@ -147,7 +147,7 @@ class FoundationBert(BertModel):
         # 我们显式地请求下载 train_config.yaml
         try:
             # 这一步会检查缓存，如果没有则从云端下载并返回本地绝对路径
-            config_file_path = hf_hub_download(
+            model_config = hf_hub_download(
                 repo_id=pretrained_model_name_or_path,
                 filename="train_config.yaml",
                 revision=kwargs.get("revision", "main")
@@ -156,7 +156,7 @@ class FoundationBert(BertModel):
             # 备选方案：如果本地路径已存在（例如 Snigdaa 的用法）
             model_config = os.path.join(pretrained_model_name_or_path, "train_config.yaml")
 
-        print(f"✅ Successfully located config at: {config_file_path}")
+        print(f"✅ Successfully located config at: {model_config}")
         with open(model_config, 'r') as f:
             config = yaml.load(f, Loader=MyLoader)