INSTALLER_OPTS replaces the default --cookbook=. value, so the docs
now show the full invocation with --cookbook=. included and recommend
using the config file approach instead.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Reorganized testing section to cover both Phase 1 (post-build script)
and Phase 2 (installer-native) workflows. Added unit test commands.
Removed mtools dependency from limitations.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Documents the two-phase GRUB integration approach (post-build script
then installer-native), build notes for the three cookbook workarounds,
and measured artifact sizes. Sets efi_partition_size=16 in redbear-full
to accommodate GRUB plus Redox bootloader on the ESP.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>