Initial Das OS 0.1.0: Void Linux live ISO with Xfce

- xbps-src templates: das-theme (adw-gtk3-based GTK themes, generated
  xfwm4 frames, wallpapers, logo), das-settings (Xfce, panel, LightDM
  defaults in /etc/xdg/das), adw-gtk3 and font-jetbrains-mono
- void-mklive profile in live/: packages, runit services, rootfs overlay,
  Ukrainian locale, live user with autologin
- Void builder container, build scripts, QEMU runner and Makefile
- Bilingual README with screenshots

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

srcpkgs/das-settings/files/bin/das-session-init

@@ -0,0 +1,35 @@
+#!/bin/bash
+# Applies Das OS per-user defaults that cannot be shipped as static xfconf files.
+# xfdesktop keys wallpapers by monitor connector name (eDP-1, HDMI-1, Virtual-1...),
+# which is only known inside the session. Runs once per user.
+set -u
+
+marker="${XDG_CONFIG_HOME:-$HOME/.config}/das/session-init.done"
+[[ -e $marker ]] && exit 0
+
+wallpaper=/usr/share/backgrounds/das/das-light.svg
+if [[ $(xfconf-query -c xsettings -p /Net/ThemeName 2>/dev/null) == *-Dark ]]; then
+  wallpaper=/usr/share/backgrounds/das/das-dark.svg
+fi
+
+# Sets an xfconf property, creating it when it does not exist yet.
+set_prop() {
+  local prop=$1 type=$2 value=$3
+  xfconf-query -c xfce4-desktop -p "$prop" -s "$value" 2>/dev/null ||
+    xfconf-query -c xfce4-desktop -p "$prop" -n -t "$type" -s "$value"
+}
+
+# "xrandr --listactivemonitors" prints a header, then one line per monitor ending in its connector name.
+monitors=$(xrandr --listactivemonitors 2>/dev/null | awk 'NR > 1 { print $NF }')
+if [[ -z $monitors ]]; then
+  echo "das-session-init: no active monitors found, will retry at next login" >&2
+  exit 1
+fi
+
+for monitor in $monitors; do
+  base="/backdrop/screen0/monitor${monitor}/workspace0"
+  set_prop "$base/last-image" string "$wallpaper"
+  set_prop "$base/image-style" int 5 # zoomed: fill the screen, keep proportions
+done
+
+mkdir -p "${marker%/*}" && touch "$marker"