Restore post-build GRUB and isolinux sync

iso/builder/build.sh

@@ -745,7 +745,6 @@ menuentry "EASY-BEE -- no GUI / no X11" {
     initrd  ${initrd}
 }
 
-
 if [ "\${grub_platform}" = "efi" ]; then
     menuentry "Memory Test (memtest86+)" {
         chainloader /boot/memtest86+x64.efi
@@ -852,60 +851,6 @@ enforce_live_build_bootloader_assets() {
             echo "bootloader sync: WARNING: could not extract live entry from $isolinux_cfg" >&2
         fi
     fi
-
-    sync_efi_grub_theme_assets "$lb_dir"
-}
-
-fat_image_has_file() {
-    img="$1"
-    path="$2"
-    mtype -i "$img" "$path" >/dev/null 2>&1
-}
-
-is_efi_grub_fat_image() {
-    img="$1"
-    fat_image_has_file "$img" "::/EFI/boot/grubx64.efi" || return 1
-    fat_image_has_file "$img" "::/boot/grub/grub.cfg" || return 1
-    return 0
-}
-
-copy_file_to_fat_image() {
-    img="$1"
-    src="$2"
-    dst="$3"
-    mcopy -o -i "$img" "$src" "$dst" >/dev/null
-}
-
-sync_efi_grub_theme_assets() {
-    lb_dir="$1"
-    found=0
-
-    for img in $(find "$lb_dir" -type f \( -name '*.img' -o -name '*.ima' -o -name '*.fat' \) 2>/dev/null); do
-        if ! is_efi_grub_fat_image "$img"; then
-            continue
-        fi
-        found=1
-        echo "bootloader sync: patching EFI GRUB image $img"
-        mmd -i "$img" "::/boot" >/dev/null 2>&1 || true
-        mmd -i "$img" "::/boot/grub" >/dev/null 2>&1 || true
-
-        copy_file_to_fat_image "$img" "${BUILDER_DIR}/config/bootloaders/grub-efi/config.cfg" "::/boot/grub/config.cfg"
-        copy_file_to_fat_image "$img" "${BUILDER_DIR}/config/bootloaders/grub-efi/theme.cfg" "::/boot/grub/theme.cfg"
-
-        fat_image_has_file "$img" "::/boot/grub/config.cfg" || {
-            echo "ERROR: EFI GRUB image missing /boot/grub/config.cfg after sync: $img" >&2
-            exit 1
-        }
-        fat_image_has_file "$img" "::/boot/grub/theme.cfg" || {
-            echo "ERROR: EFI GRUB image missing /boot/grub/theme.cfg after sync: $img" >&2
-            exit 1
-        }
-    done
-
-    if [ "$found" != "1" ]; then
-        echo "ERROR: no EFI GRUB FAT image found in live-build workdir; cannot sync theme assets" >&2
-        exit 1
-    fi
 }
 
 copy_memtest_from_deb() {