feat: add Antergos NeXT Minimal (Xfce) profile — lightweight ISO edition

Introduces iso-profiles/antergos-minimal/, a new Xfce-based profile for
building a lightweight Antergos NeXT ISO under the 2 GB GitHub Releases
limit (the full Plasma profile produces ~2.15 GB).

Profile structure:
- profile.yaml: Xfce4 desktop, dinit-only init packages, Falkon browser,
  minimal app selection, antergos-xfce-theme included in rootfs
- root-overlay/: SDDM configured for xfce.desktop, GRUB theme pointed to
  antergos, xfconf settings for Antergos-NeXT GTK/xfwm4 theme
- live-overlay/: Calamares offline + online configs, netinstall with
  multiple DE options (Plasma, Xfce, Cinnamon, MATE, LXQt, i3, Sway,
  Hyprland), notesqml@minimal-info step explaining the edition rationale,
  basestrap operations for antergos-release/grub-theme/keyring, display
  manager selection (SDDM/LightDM/LXDM/LY), audio services (pipewire),
  and antergos-xfce-theme in the Xfce subgroup

Default Xfce theme is set to Antergos-NeXT (Numix-derived, blue accent)
via xfconf XML in both live-overlay and root-overlay skel directories.

iso-profiles/antergos-minimal/live-overlay/etc/calamares-offline/modules/services-artix.conf

@@ -0,0 +1,24 @@
+---
+command: artix-service
+
+services:
+  - name: "acpid"
+    action: "enable"
+  - name: "bluetoothd"
+    action: "enable"
+  - name: "cronie"
+    action: "enable"
+  - name: "cupsd"
+    action: "enable"
+  - name: "dbus"
+    action: "enable"
+  - name: "dhcpcd"
+    action: "enable"
+  - name: "NetworkManager"
+    action: "enable"
+  - name: "power-profiles-daemon"
+    action: "enable"
+  - name: "sddm"
+    action: "enable"
+  - name: "syslog-ng"
+    action: "enable"