feat: HDMI refresh boost (Steam Machine, pinned kernel)

The pinned 7.1.6 kernel doesn't read the extra EDID block (HDMI Forum
EEODB) where monitors list their fast modes, and does no HDMI 2.1, so HDMI
displays often stay at 60 Hz. The new menu item reads the display's EDID
over DDC, calculates the highest rate that fits HDMI 2.0 at the desktop
resolution (rounded down to ten, plus the hundred below as a safe option),
tests each step live with a confirmation, and makes the confirmed ones
permanent through drm.edid_firmware (Limine, sdboot-manage or GRUB).

steamify.sh

@@ -15,11 +15,11 @@
 set -uo pipefail
 
 # Release version, see CHANGELOG.md.
-VERSION=1.1.4
+VERSION=1.2.0
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
-for lib in common state packages login-manager single-user steam-desktop steam-machine cec boot-session vapor-theme steamos-extras bios desktop-shortcut wizard-shortcut menu backend; do
+for lib in common state packages login-manager single-user steam-desktop steam-machine hdmi-refresh cec boot-session vapor-theme steamos-extras bios desktop-shortcut wizard-shortcut menu backend; do
     # shellcheck source=/dev/null
     source "$SCRIPT_DIR/lib/$lib.sh"
 done