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-theme/files/gtk/DasOS-Dark/gtk-3.0/gtk.css

@@ -0,0 +1,14 @@
+/* Das OS dark: adw-gtk3-dark with the Das OS accent colours. */
+@import url("../../adw-gtk3-dark/gtk-3.0/gtk.css");
+
+@define-color accent_bg_color #3f78e4;
+@define-color accent_fg_color #ffffff;
+@define-color accent_color #7aa7f5;
+
+/* A dark panel that matches the window frames instead of pure black. */
+@define-color panel_bg_color #1b1f27;
+@define-color panel_fg_color #e3e6ec;
+
+.xfce4-panel.background {
+  border-top: 1px solid alpha(@panel_fg_color, 0.08);
+}