refactor(api): 优化获取节点失败的错误信息

- 在 inbound 请求失败时，将错误信息详细输出
- 有助于调试和排查问题

api/client/add.js

@@ -13,7 +13,7 @@ module.exports = async (ctx) => {
     });
   }
   const inbound = await ins.get(`/panel/api/inbounds/get/${id}`);
-  if (!inbound?.success) return (ctx.body = { code: "1", msg: "获取节点失败" });
+  if (!inbound?.success) return (ctx.body = { code: "1", msg: `获取节点失败:${inbound}` });
   uuid = uuid || randomUUID();
   email = email || uuid.split("-")[0];
   if (expiryTime != 0) {