OpenWrt 25.x switched from opkg to apk as the default package manager,
so devices like the Cudy TR1200 on 25.12.4 don't have /usr/bin/opkg.
When opkg is missing but apk is present, install opkg through apk first
so the rest of the provisioning flow can proceed unchanged.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>