feat: DE selector with packagechooser, video wallpaper fix, slideshow redesign

- Replace dead init selector (packagechooser.conf, 303 lines) with
  packagechooser_de.conf + packagechooser_dm.conf (netinstall-add method)
- Remove init SVGs (dinit, openrc, runit, s6)
- Clean netinstall.yaml — Desktop group removed, DEs added dynamically
- Update calamares-online/settings.conf with packagechooser@de + @dm instances
- Fix set-antergos-wallpaper.sh: Array() not [], no reloadConfig()
- Rewrite installer, launcher, and live-overlay docs

iso-profiles/antergos/live-overlay/etc/calamares/modules/netinstall.yaml

@@ -115,187 +115,7 @@
     - artools-iso
     - artools-pkg
 
-- name: "Desktop"
-  description: "DE"
-  selected: true
-  critical: false
-  subgroups:
-    - name: "Plasma"
-      description: "KDE Plasma Desktop"
-      selected: false
-      packages:
-        - antergos-next-desktop-settings
-        - ark
-        - bluedevil
-        - breeze-gtk
-        - dolphin
-        - dolphin-plugins
-        - ffmpegthumbs
-        - gwenview
-        - kate
-        - kcalc
-        - kde-cli-tools
-        - kde-gtk-config
-        - kdeconnect
-        - kdegraphics-thumbnailers
-        - kdenetwork-filesharing
-        - kdeplasma-addons
-        - keditbookmarks
-        - kfind
-        - kgpg
-        - kinfocenter
-        - kio-admin
-        - kio-extras
-        - kio-fuse
-        - konsole
-        - konversation
-        - kscreen
-        - kwallet-pam
-        - kwalletmanager
-        - kwayland-integration
-        - okular
-        - partitionmanager
-        - plasma-browser-integration
-        - plasma-desktop
-        - plasma-disks
-        - plasma-nm
-        - plasma-pa
-        - plasma-systemmonitor
-        - plasma-workspace
-        - powerdevil
-        - print-manager
-        - qt6-imageformats
-        - spectacle
-        - xdg-desktop-portal-kde
-        - xsettingsd
-    - name: "Xfce"
-      description: "Xfce Desktop"
-      selected: false
-      packages:
-        - exo
-        - garcon
-        - thunar
-        - thunar-volman
-        - tumbler
-        - xfce4-appfinder
-        - xfce4-panel
-        - xfce4-power-manager
-        - xfce4-session
-        - xfce4-settings
-        - xfce4-terminal
-        - xfconf
-        - xfdesktop
-        - xfwm4
-        - xfwm4-themes
-        - mousepad
-        - parole
-        - ristretto
-        - thunar-archive-plugin
-        - thunar-media-tags-plugin
-        - xfburn
-        - xfce4-clipman-plugin
-        - xfce4-notifyd
-        - xfce4-pulseaudio-plugin
-        - xfce4-screenshooter
-        - xfce4-screensaver
-        - xfce4-taskmanager
-        - xfce4-whiskermenu-plugin
-    - name: "Cinnamon"
-      description: "Cinnamon Desktop"
-      selected: false
-      packages:
-        - cinnamon
-        - cinnamon-control-center
-        - cinnamon-desktop
-        - cinnamon-menus
-        - cinnamon-screensaver
-        - cinnamon-session
-        - cinnamon-settings-daemon
-        - cinnamon-translations
-    - name: "MATE"
-      description: "MATE Desktop"
-      selected: false
-      packages:
-        - caja
-        - marco
-        - mate-backgrounds
-        - mate-control-center
-        - mate-desktop
-        - mate-icon-theme
-        - mate-menus
-        - mate-notification-daemon
-        - mate-panel
-        - mate-polkit
-        - mate-session-manager
-        - mate-settings-daemon
-        - mate-themes
-        - mate-user-guide
-        - atril
-        - eom
-        - mate-applets
-        - mate-calc
-        - mate-power-manager
-        - mate-screensaver
-        - mate-system-monitor
-        - mate-terminal
-        - mate-utils
-        - pluma
-    - name: "LXQt"
-      description: "LXQt Desktop"
-      selected: false
-      packages:
-        - lximage-qt
-        - lxqt-about
-        - lxqt-admin
-        - lxqt-archiver
-        - lxqt-config
-        - lxqt-globalkeys
-        - lxqt-menu-data
-        - lxqt-notificationd
-        - lxqt-openssh-askpass
-        - lxqt-panel
-        - lxqt-policykit
-        - lxqt-powermanagement
-        - lxqt-qtplugin
-        - lxqt-runner
-        - lxqt-session
-        - lxqt-sudo
-        - lxqt-themes
-        - obconf-qt
-        - openbox
-        - pavucontrol-qt
-        - pcmanfm-qt
-        - qps
-        - qterminal
-        - screengrab
-        - xdg-desktop-portal-lxqt
-    - name: "i3"
-      description: "i3 Tiling WM"
-      selected: false
-      packages:
-        - i3-wm
-        - i3blocks
-        - i3lock
-        - i3status
-    - name: "Sway"
-      description: "Sway Wayland Compositor"
-      selected: false
-      packages:
-        - sway
-        - swaybg
-        - swayidle
-        - swaylock
-    - name: "Hyprland"
-      description: "Hyprland Wayland Compositor"
-      selected: false
-      packages:
-        - hyprland
-        - xdg-desktop-portal-hyprland
-    - name: "COSMIC"
-      description: "COSMIC Desktop (Rust/Wayland — select greetd as DM)"
-      selected: false
-      packages:
-        - cosmic
+
 
 - name: "SDDM"
   description: "SDDM display manager"