systemctl --user goes through user_systemctl, which only changes unit files
without a session; the theme lets Plasma build Vapor's layout at the first
login when the layout is still /etc/skel's; a one-time first-login autostart
sets up single user's launcher and opens the app.
Kernels >= 7.2 keep the firmware's S4/S5 wake bit on GPIO pin 18, so the
Steam Machine starts again right after powering off. Steam Machine
support now builds a DKMS module (patches/steamify-fremont-poweroff.c)
that clears it before power-off, for every kernel. The kernel pin is no
longer ticked by default. Module sources and patches move to patches/,
embedded by the single-file build.
HDMI-CEC runs before Steam Machine support, which installs steamos-manager,
so its configure-cecd unit couldn't be enabled. Link them from Steam Machine
support too.
With the kernel pin ticked, install 7.1.6-1 before the LED driver, so DKMS
builds it once. steamos-manager checks for cecd only at its start: order it
after cecd.
theupriser