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/lightdm/50-das-greeter.conf

@@ -0,0 +1,13 @@
+# Das OS look for the login screen.
+[greeter]
+background=/usr/share/backgrounds/das/das-light.svg
+theme-name=DasOS
+icon-theme-name=Papirus
+font-name=Inter 11
+cursor-theme-name=Adwaita
+cursor-theme-size=24
+xft-antialias=true
+xft-hintstyle=hintslight
+xft-rgba=rgb
+indicators=~host;~spacer;~clock;~spacer;~layout;~language;~session;~a11y;~power
+clock-format=%H:%M   %d.%m.%Y

srcpkgs/das-settings/files/lightdm/50-das.conf

@@ -0,0 +1,4 @@
+# Das OS: LightDM with the GTK greeter starting an Xfce session.
+[Seat:*]
+greeter-session=lightdm-gtk-greeter
+user-session=xfce