d67ca0f3e0
Add the I38 desktop stack to the Raspberry Pi image build, including Cthulhu, XLibre, nodm, xorg-xinit, and I38 runtime Python dependencies. Generate the default stormux user's I38 configuration during image creation with the non-interactive I38 mode, configure nodm for that generated xinitrc, and set Speech Dispatcher to use RHVoice by default. Harden the Pi build for larger GUI images by raising the default image size to 8 GB, skipping mkinitcpio autodetect for the target image initramfs, and validating the root filesystem before compression. Rework first boot so volume calibration runs before Fenrir starts, temporary tty1 autologin and passwordless sudo are removed during setup, I38/nodm startup is selected explicitly, and physical versus headless X configuration is written before nodm starts. Document the Pi GUI rollout in gui.md and refresh README size and desktop references.