Add power settings for the lighting, bump to 1.4.0

New Power page:
- toggle for the firmware's 30 s keyboard backlight timeout
- idle timeout for keyboard and lightbar, separately for AC and battery;
  predatord watches all input devices and restores the lighting on the
  next input
- battery rules: dimmed keyboard brightness, keyboard off, lightbar off

The rules only change what is sent to the hardware; the saved lighting
settings stay untouched.

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

packaging/arch/PKGBUILD

@@ -5,7 +5,7 @@
 #   sudo pacman -U predator-control-*.pkg.tar.zst
 
 pkgname=predator-control
-pkgver=1.3.0
+pkgver=1.4.0
 pkgrel=1
 pkgdesc="PredatorSense replacement for Acer Predator laptops: performance modes, fans, keyboard RGB, lightbar, battery (Qt app + Plasma widget)"
 arch=('any')
@@ -22,7 +22,7 @@ install=predator-control.install
 source=()
 
 _src="$(realpath "$startdir/../..")"
-_modver=1.3.0
+_modver=1.4.0
 
 package() {
     cd "$_src"