fix:修复base中创建知识库时直接将basemodel转为json时的报错，先转为dict再转为json

src/knowledge/base.py

@@ -137,12 +137,13 @@ class KnowledgeBase(ABC):
         db_id = f"kb_{hashstr(database_name, with_salt=True)}"
 
         # 创建数据库记录
+        # 确保 Pydantic 模型被转换为字典，以便 JSON 序列化
         self.databases_meta[db_id] = {
             "name": database_name,
             "description": description,
             "kb_type": self.kb_type,
-            "embed_info": embed_info,
-            "llm_info": llm_info,
+            "embed_info": embed_info.model_dump() if hasattr(embed_info, 'model_dump') else embed_info,
+            "llm_info": llm_info.model_dump() if hasattr(llm_info, 'model_dump') else llm_info,
             "metadata": kwargs,
             "created_at": utc_isoformat(),
         }