NAT 主机会在 Alpine 的“安装”环境无法正确配置网络

原来的系统 (Original system):

Debian

要安装的系统 (System to be installed):

Ubuntu

遇到的问题 (Issue):

在 NAT 主机上运行 `bash reinstall.sh ubuntu 26.04 --minimal` ，重启进入 Alpine 环境后，无法正确配置网络：

原系统的网络配置类似：

```
auto eth0
iface eth0 inet static
address 172.29.209.136/12
# dns-* options are implemented by the resolvconf package, if installed
dns-nameservers 8.8.8.8 1.1.1.1
dns-search debian
gateway 172.16.0.1
```

运行 reinstall.sh 后，/reinstall-tmp/initrd/init 里的 configure_ip 的 /initrd-network.sh 后面是有正确的网络配置，但是 /reinstall-tmp/initrd/initrd-network.sh 似乎没有正常运行。目前解决方法是修改 /reinstall-tmp/initrd/initrd-network.sh 只保留静态配置逻辑

Start by reproducing the NAT installation with `bash reinstall.sh ubuntu 26.04 --minimal`, then inspect `/reinstall-tmp/initrd/init`, the `configure_ip` path, and `/reinstall-tmp/initrd/initrd-network.sh`. Compare the generated network configuration with the static configuration described in the issue; done means the Alpine installation environment configures networking correctly without the reported workaround.

Written by the indexing model from the issue text.