fix: 更新main.py逻辑

config/settings.py

@@ -71,12 +71,17 @@ class MilvusCfg(BaseSettings):
     token: Optional[str] = None  # 可缺省（无需鉴权时留空）
     user: Optional[str] = None
     password: Optional[str] = None
-    db_name: Optional[str] = None
+    db: Optional[str] = None
     connect_timeout: int  # 建连/通道就绪超时（构造是急切连接，必须短）
     timeout: int  # 数据操作超时，调用处可覆盖
 
     model_config = SettingsConfigDict(env_prefix="MILVUS_", env_file=_ENV_FILE, extra="ignore")
 
+    @property
+    def db_name(self) -> Optional[str]:
+        """Compatibility name used by the Milvus client wrapper."""
+        return self.db
+
 
 class LLMCfg(BaseSettings):
     """大模型配置：本地 Ollama / OpenAI 兼容 API 双模式见 tool/llm.py。"""
@@ -134,4 +139,4 @@ class Settings(BaseSettings):
     model_config = SettingsConfigDict(env_file=_ENV_FILE, extra="ignore")
 
 
-settings = Settings()
+settings = Settings()