feat: major Calamares overhaul — dracut migration, branding polish, online/offline installer split

=== Calamares (core) ===
- Unskip packagechooserq from _skip_modules so it compiles in
- pkgrel 2→3

=== Calamares Branding ===
branding.desc:
- Blue Antergos color scheme (#4A9EFF accent, #20252B sidebar)
- New Antergos logo/icon PNGs from cnchi assets
- Larger window (860x540)
- Fix sidebar/navigation to widget mode

stylesheet.qss:
- Blue-themed QSS with gradients, styled buttons/inputs/sidebar

show.qml:
- 6-slide Calamares slideshow: welcome, EndeavourOS base, DE list,
  Antergos tools, finishing, thank-you (dark slide)

dracut migration:
- dracut.conf (NEW): initramfsName for dracut module compatibility
- Remove mkinitcpio reference, dracut handles initramfs generation

=== Online/Offline Installer Split ===
Problem: unpackfs (GNOME squashfs) + netinstall (selected DE) installs
two DEs — wasteful and messy.
Solution: Two entirely separate Calamares configurations.

settings_offline.conf (NEW):
- Traditional unpackfs path, no netinstall steps
- Installs GNOME from pre-built squashfs (current behavior)
- Used by default `calamares` or via `calamares -c /etc/calamares-offline`

settings_online.conf (NEW):
- No unpackfs — everything installed from internet via netinstall
- netinstall in both show (DE selection) and exec (package install)
- Base system + Antergos packages as hidden/immutable groups
- Used via `calamares -c /etc/calamares-online`

netinstall.yaml (NEW):
- Base System (hidden, immutable): kernel, base, firmware, network
- Antergos Packages (hidden, immutable): wallpapers, welcome, yay, calamares
- 8 Desktop Environments: KDE, GNOME, Xfce, Budgie, Cinnamon, MATE, LXQt, i3/Sway
- Hardware Support group: GPU drivers, vulkan, pipewire

netinstall.conf (NEW): groupsUrl pointing to netinstall.yaml

welcome.conf (NEW): internet check (informational), 8GB storage/2GB RAM/power required

calamares-next.sh (NEW): Launcher script — zenity/kdialog/dialog
choice between Offline and Online, runs Calamares with the right config.
Checks internet connectivity before starting online install.

PKGBUILD install layout:
- Branding shared at /usr/share/calamares/branding/antergos-next/
- Modules shared at /etc/calamares/modules/
- /etc/calamares-offline/  — settings.conf for offline
- /etc/calamares-online/   — settings.conf for online
- /etc/calamares/settings.conf → symlink to offline (default)
- /usr/bin/calamares-next  — launcher script

=== Antergos Welcome ===
PKGBUILD: copy data/preferences.json to package root (fixes
runtime preferences loading in subdirectory layout)

packages/calamares-branding-antergos-next/netinstall.yaml

@@ -0,0 +1,126 @@
+---
+- name: "Desktop Environments"
+  description: "Select the desktop environment to install. Choose one."
+  selected: false
+  hidden: false
+  immutable: false
+  critical: false
+  subgroups:
+    - name: "KDE Plasma"
+      description: "Full-featured, modern desktop with KDE applications"
+      packages:
+        - plasma-meta
+        - kde-applications-meta
+      selected: false
+      critical: false
+    - name: "GNOME"
+      description: "Modern and streamlined desktop environment"
+      packages:
+        - gnome
+        - gnome-tweaks
+        - gnome-shell-extensions
+      selected: true
+      critical: false
+    - name: "Xfce"
+      description: "Fast and lightweight classic desktop"
+      packages:
+        - xfce4
+        - xfce4-goodies
+      selected: false
+      critical: false
+    - name: "Budgie"
+      description: "Elegant and simple desktop environment"
+      packages:
+        - budgie-desktop
+        - budgie-desktop-view
+        - budgie-screensaver
+      selected: false
+      critical: false
+    - name: "Cinnamon"
+      description: "Traditional desktop with modern conventions"
+      packages:
+        - cinnamon
+        - cinnamon-translations
+      selected: false
+      critical: false
+    - name: "MATE"
+      description: "Intuitive and attractive classic desktop"
+      packages:
+        - mate
+        - mate-extra
+      selected: false
+      critical: false
+    - name: "LXQt"
+      description: "Lightweight Qt desktop environment"
+      packages:
+        - lxqt
+        - lxqt-connman-applet
+        - oxygen-icons
+      selected: false
+      critical: false
+    - name: "i3 / Sway"
+      description: "Tiling window managers for power users"
+      packages:
+        - i3-wm
+        - i3status
+        - i3lock
+        - dmenu
+        - sway
+        - waybar
+        - wofi
+      selected: false
+      critical: false
+
+- name: "Base System"
+  description: "Core system packages for a functional Arch Linux installation"
+  selected: true
+  hidden: true
+  immutable: true
+  critical: true
+  packages:
+    - base
+    - base-devel
+    - linux
+    - linux-firmware
+    - linux-headers
+    - amd-ucode
+    - intel-ucode
+    - networkmanager
+    - network-manager-applet
+    - sudo
+    - nano
+    - which
+    - man-db
+    - man-pages
+
+- name: "Antergos Packages"
+  description: "Antergos NeXT branding and tools"
+  selected: true
+  hidden: true
+  immutable: true
+  critical: false
+  packages:
+    - antergos-wallpapers
+    - antergos-welcome
+    - yay
+    - calamares
+    - calamares-branding-antergos-next
+    - firefox
+
+- name: "Hardware Support"
+  description: "Additional hardware drivers and firmware"
+  selected: false
+  hidden: false
+  immutable: false
+  critical: false
+  packages:
+    - mesa
+    - mesa-utils
+    - vulkan-intel
+    - vulkan-radeon
+    - nvidia-open
+    - nvidia-utils
+    - pipewire
+    - pipewire-pulse
+    - pipewire-alsa
+    - wireplumber