Document the greetd/ReGreet greeter in the top-level README and the T400
and Mac Pro install notes, including that the user account needs a
password set before the greeter can authenticate.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Add system/machine/{T400,MacPro31}/README.md covering the placeholder
hardware-configuration regeneration, partition labels, bootloader selection
(T400 boot variants; Mac Pro EFI quirks), and GPU notes. Link each from its
configuration.nix header, and refresh the top-level README host table (T400
replaces X1, Mac Pro 3,1 added) with links to both.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Emma Thorpe