feat: Live session: power-off fix built for the ISO's kernels, Vapor look and layout at the live login

.gitignore

@@ -24,3 +24,5 @@ archiso/airootfs/etc/version-tag
 archiso/airootfs/usr/local/share/steamify/
 archiso/airootfs/usr/lib/libboost_*
 archiso/airootfs/etc/steammachine-iso-build
+archiso/airootfs/usr/lib/modules/
+archiso/airootfs/etc/modules-load.d/steamify-fremont-poweroff.conf

TODO.md

@@ -2,12 +2,17 @@
 
 ## Open
 
-1. **Steamify PR**: `feat/defaults-mode` (2.6.0, `b948c20`) in
+1. **Test the live session** after the next build (`build-live-modules.sh`
+   runs in the container before buildiso.sh): Vapor look and layout at the
+   live login, `lsmod | grep steamify` in the live session (on the Steam
+   Machine it loads; in the VM with `--fremont` too), and shutting down from
+   the live session on the real Steam Machine stays off.
+2. **Steamify PR**: `feat/defaults-mode` (2.6.0, `b948c20`) in
    steamify-cachyos, pushed, no PR yet (checked 2026-09-27: not on main,
    newest release v2.5.2). Ready: open it; the user
    merges (never commit to main). The ISO's first-login step needs 2.6.0
    released.
-2. **Test on the real Steam Machine** from a USB stick (gamescope, LEDs, CEC,
+3. **Test on the real Steam Machine** from a USB stick (gamescope, LEDs, CEC,
    power-off) before calling the ISO usable.
 
 ## Done
@@ -30,16 +35,6 @@
 
 ## Later
 
-- **Power-off fix in the live session.** Without it the Steam Machine starts
-  again right after shutting down from the live ISO. Build
-  `steamify-fremont-poweroff.ko` in `steamify-prepare.sh` against the headers
-  of the ISO's kernel, put it in `airootfs/usr/lib/modules/<version>/extra`
-  and run depmod (small); or ship DKMS packages from a local repo (~250 MB of
-  headers on the ISO). Later maybe the CEC and LED drivers the same way.
-- **Vapor theme in the live session.** Add `cachyos-vapor` to
-  `packages_desktop.x86_64` and set it as the live user's look and feel in
-  `airootfs/etc/skel` (kdeglobals `LookAndFeelPackage`, no layout file, so
-  Plasma lays out Vapor at the live login).
 - **Steamify wizard pages in the installer**, before anything is installed:
   the same choices as Steamify's menu (conversion, boot into gamescope or
   desktop, theme, Deck icons, single user, shortcut + non-Steam game,

archiso/airootfs/etc/xdg/autostart/steamify-live-theme.desktop

@@ -0,0 +1,7 @@
+[Desktop Entry]
+Type=Application
+Name=Steamify live theme
+Exec=/usr/local/bin/steamify-live-theme
+OnlyShowIn=KDE;
+X-KDE-autostart-phase=2
+NoDisplay=true

archiso/airootfs/usr/local/bin/steamify-live-theme

@@ -0,0 +1,7 @@
+#!/bin/bash
+# The live session in the Vapor look, with its SteamOS desktop layout.
+# CachyOS's own layout comes from /etc/skel, which the live user gets before
+# this runs; lookandfeeltool needs plasmashell up to replace it.
+for _ in $(seq 30); do pgrep -u "$USER" -x plasmashell >/dev/null && break; sleep 1; done
+sleep 2
+lookandfeeltool -a com.valve.vapor.desktop --resetLayout

archiso/packages_desktop.x86_64

@@ -90,6 +90,7 @@ linux-cachyos
 linux-cachyos-nvidia-open
 linux-cachyos-zfs
 linux-firmware
+cachyos-vapor
 linux-firmware-marvell
 lsb-release
 lsof

archiso/profiledef.sh

@@ -28,6 +28,7 @@ file_permissions=(
   ["/usr/local/bin/choose-mirror"]="0:0:755"
   ["/usr/local/bin/dmcheck"]="0:0:755"
   ["/usr/local/bin/steamify-install"]="0:0:755"
+  ["/usr/local/bin/steamify-live-theme"]="0:0:755"
   ["/usr/local/bin/calamares-online.sh"]="0:0:755"
   ["/usr/local/bin/remove-nvidia"]="0:0:755"
   ["/usr/local/bin/removeun"]="0:0:755"

build-live-modules.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+# build-live-modules.sh: builds Steamify's power-off fix for the live ISO's
+# kernels, so the Steam Machine stays off after shutting down from the live
+# session (recent kernels keep a firmware wake bit set; see Steamify's
+# patches/steamify-fremont-poweroff.c). Run as root in the build container,
+# after steamify-prepare.sh and before buildiso.sh: the headers come from the
+# same repos at the same time as the ISO's kernels, so the versions match.
+# The module checks for Fremont itself and does nothing on other hardware.
+set -euo pipefail
+cd "$(dirname "$0")"
+src=archiso/airootfs/usr/local/share/steamify/steamify-fremont-poweroff.c
+[[ -f "$src" ]] || { echo "No $src: run steamify-prepare.sh first." >&2; exit 1; }
+
+pacman -S --needed --noconfirm base-devel clang llvm lld linux-cachyos-headers linux-cachyos-lts-headers >/dev/null
+work="$(mktemp -d)"
+cp "$src" "$work/"
+echo 'obj-m += steamify-fremont-poweroff.o' > "$work/Makefile"
+for build in /usr/lib/modules/*/build; do
+    kver="$(basename "$(dirname "$build")")"
+    # CachyOS's kernels differ in compiler (linux-cachyos is clang-built):
+    # build with the one the kernel was built with.
+    llvm=()
+    grep -q '^CONFIG_CC_IS_CLANG=y' "$build/.config" && llvm=(LLVM=1)
+    make -s -C "$build" M="$work" "${llvm[@]}" clean modules
+    install -Dm644 "$work/steamify-fremont-poweroff.ko" \
+        "archiso/airootfs/usr/lib/modules/$kver/extra/steamify-fremont-poweroff.ko"
+    echo "Power-off fix built for $kver."
+done
+rm -rf "$work"
+install -Dm644 /dev/stdin archiso/airootfs/etc/modules-load.d/steamify-fremont-poweroff.conf <<< 'steamify-fremont-poweroff'

steamify-prepare.sh

@@ -11,6 +11,13 @@ if [[ -n "${1:-}" ]]; then
 else
     curl -fsSL https://github.com/theupriser/steamify-cachyos/releases/latest/download/steamify.sh -o "$dest"
 fi
+# The power-off fix's source, for build-live-modules.sh (live session).
+poweroff="$(dirname "$dest")/steamify-fremont-poweroff.c"
+if [[ -n "${1:-}" ]]; then
+    cp "$1/patches/steamify-fremont-poweroff.c" "$poweroff"
+else
+    curl -fsSL https://raw.githubusercontent.com/theupriser/steamify-cachyos/main/patches/steamify-fremont-poweroff.c -o "$poweroff"
+fi
 grep -q -- '--defaults' "$dest" || { echo "This Steamify has no --defaults (needs 2.6.0 or newer)." >&2; exit 1; }
 chmod 755 "$dest"
 # Temporary: cachyos-calamares-next 3.4.2-13 is linked against Boost 1.91