关于源码硬编码上海时区

原来的系统 (Original system): ubuntu26.04

要安装的系统 (System to be installed): ubuntu26.04

遇到的问题 (Issue): 你好，脚本dd linux系统时，会把默认时区修改成上海，我看源码，是直接硬编码的。这个行为在今天看来，所带来的后果是非常严重的，claude现在检测到上海时区就秒，请问是否可以在dd时尊重默认时区

Search the installation and DD flow for the hard-coded Shanghai timezone and trace where it is applied. Verify the behavior on Ubuntu 26.04, then confirm that DD no longer forces Shanghai and instead preserves the system's default timezone.

Written by the indexing model from the issue text.