feat: expand Calamares installer with DM chooser, explicit DE packages, and custom packages module

- Add packagechooser@dm instance for display manager selection (SDDM/LightDM/LXDM/LY)
- Expand desktop environment package lists (Xfce MATE LXQt i3) with explicit packages
- Change plasma -> plasma-meta and lsb-release -> antergos-lsb-release
- Add bootloader, displaymanager, grubcfg, postcfg, services-artix module configs
- Install antergos-release, antergos-wallpapers, antergos-grub-theme via basestrap
- Add custom packages/main.py with one-at-a-time install and --overwrite='*'
- Add --overwrite='*' to basestrap main.py for pacman -Sy operations

iso-profiles/antergos/live-overlay/etc/calamares/modules/postcfg.conf

@@ -0,0 +1,13 @@
+---
+# set at iso build time
+initsys: none
+
+user-services:
+  - name: dbus
+    action: enable
+  - name: pipewire
+    action: enable
+  - name: pipewire-pulse
+    action: enable
+  - name: wireplumber
+    action: enable