Refactored installer into modular library structure with improved error handling and logging.

The changes include:
- Split monolithic script into lib/, config/, profiles/, and files/ directories
- Added error handling with cleanup on failure
- Added installation logging to /var/log/arch-install.log
- Added username validation

lib/desktop/xfce.sh

@@ -0,0 +1,115 @@
+#!/bin/bash
+
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# xfce.sh - XFCE desktop environment installation
+#
+# Installs XFCE4 with LightDM and copies pre-configured user settings.
+
+# XFCE base packages
+XFCE_PACKAGES=(
+    lightdm
+    lightdm-gtk-greeter
+    lightdm-gtk-greeter-settings
+    thunar
+    thunar-archive-plugin
+    gvfs
+    xfce4-panel
+    xfce4-power-manager
+    xfce4-session
+    xfce4-settings
+    xfce4-terminal
+    xfdesktop
+    xfwm4
+    papirus-icon-theme
+    xfce4-battery-plugin
+    xfce4-notifyd
+    xfce4-whiskermenu-plugin
+    xfce4-screensaver
+    xfce4-screenshooter
+    mousepad
+    noto-fonts
+    noto-fonts-cjk
+    noto-fonts-emoji
+    noto-fonts-extra
+    pipewire
+    pipewire-alsa
+    pipewire-pulse
+    pipewire-jack
+    wireplumber
+    pavucontrol
+    xfce4-pulseaudio-plugin
+    ristretto
+    webp-pixbuf-loader
+    libopenraw
+    xarchiver
+    7zip
+    xreader
+)
+
+# Install XFCE base packages
+install_xfce_packages() {
+    chroot_install "${XFCE_PACKAGES[@]}"
+}
+
+# Enable LightDM display manager
+enable_lightdm() {
+    chroot_enable lightdm.service
+}
+
+# Configure LightDM greeter
+configure_lightdm() {
+    chroot_run sh -c "cat > /etc/lightdm/lightdm-gtk-greeter.conf" <<EOF
+[greeter]
+hide-user-image = true
+font-name = Noto Sans 10
+clock-format = %A, %B %d, %Y,%l:%M:%S %p
+theme-name = Adwaita-dark
+icon-theme-name = Papirus-Dark
+screensaver-timeout = 10
+user-background = false
+background = #77767b
+indicators = ~host;~spacer;~clock;~spacer;~power
+EOF
+}
+
+# Copy default XFCE configuration to user home
+# Arguments:
+#   $1 - username
+copy_xfce_config() {
+    local username="$1"
+    local home_dir="${MOUNT_POINT}/home/${username}"
+
+    cp -r "${HOME_CONFIG_DIR}" "${home_dir}/.config"
+
+    # Disable tumblerd (thumbnail service)
+    mkdir -p "${home_dir}/.config/systemd/user"
+    ln -s /dev/null "${home_dir}/.config/systemd/user/tumblerd.service"
+
+    # Set correct ownership (UID 1000 is typically first user)
+    chown -R 1000:1000 "${home_dir}/.config"
+}
+
+# Full XFCE installation
+# Arguments:
+#   $1 - username
+install_xfce() {
+    local username="$1"
+
+    install_xfce_packages
+    enable_lightdm
+    configure_lightdm
+    copy_xfce_config "$username"
+}