feat(grub): render grub-theme-udt's theme.txt and print its root install

theme.txt has no include, so udt-palette substitutes eight roles and the
scheme name into the sibling repo's theme.txt.in, conky-style. The accent is
the scheme's fixed one; nothing at boot can read the wallpaper.

install.sh runs that repo's build as the user and, only when it succeeds,
prints the root copy into /boot/grub/themes plus the one-time GRUB_THEME and
grub-mkconfig steps. External targets are now skipped whenever their template
is missing, not only when the repo is, so a sibling mid-setup cannot break an
install.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/install.sh b/install.sh
index 9626431..abcfd51 100755
--- a/install.sh
+++ b/install.sh
@@ -339,6 +339,24 @@ if [ -d "$sddm_repo/theme" ]; then
     echo "  printf '[Theme]\\nCurrent=udt\\n' > /etc/sddm.conf.d/udt.conf"
 fi
 
+# GRUB. Same shape as SDDM: udt-palette has rendered theme.txt, the sibling
+# repo's build assembles the theme as the user, and the root half is printed.
+# A copy, not a link: GRUB reads /boot before /home is mounted. The background
+# is a snapshot of the wallpaper, so the copy needs rerunning after a scheme
+# or wallpaper change; grub-mkconfig only when GRUB_THEME changes.
+grub_repo="$(realpath -m "$repo/../grub-theme-udt")"
+if [ -x "$grub_repo/build" ]; then
+    if "$grub_repo/build"; then
+        echo
+        echo "grub theme: run these as root to install or refresh it"
+        echo "  rm -rf /boot/grub/themes/udt && cp -r \"$grub_repo/build/udt\" /boot/grub/themes/"
+        echo "  # once: GRUB_THEME=\"/boot/grub/themes/udt/theme.txt\" in /etc/default/grub, then"
+        echo "  grub-mkconfig -o /boot/grub/grub.cfg"
+    else
+        echo "grub: its build failed, theme not refreshed" >&2
+    fi
+fi
+
 [ -n "$reloaded" ] && echo "reloaded:$reloaded"
 
 echo "installed:"