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/drivers.sh

@@ -0,0 +1,64 @@
+#!/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.
+
+# drivers.sh - Graphics driver installation
+#
+# Prompts the user to select and install graphics drivers (Intel, NVIDIA, or skip).
+
+# Intel graphics packages
+INTEL_PACKAGES=(
+    mesa
+    vulkan-intel
+    intel-media-driver
+    libva-intel-driver
+)
+
+# NVIDIA graphics packages
+NVIDIA_PACKAGES=(
+    mesa
+    nvidia-open
+    libva-nvidia-driver
+)
+
+# Install Intel graphics drivers
+install_intel_graphics() {
+    print "Installing Intel graphics drivers..."
+    chroot_install "${INTEL_PACKAGES[@]}"
+}
+
+# Install NVIDIA graphics drivers
+install_nvidia_graphics() {
+    print "Installing NVIDIA graphics drivers..."
+    chroot_install "${NVIDIA_PACKAGES[@]}"
+}
+
+# Prompt user for graphics driver selection and install
+prompt_install_graphics() {
+    print "Would you like to install graphics drivers? Type 'intel' exactly for Intel graphics drivers, 'nvidia' for NVIDIA graphics drivers, or anything else to skip."
+    read -r driver
+
+    case "$driver" in
+        "intel")
+            install_intel_graphics
+            ;;
+        "nvidia")
+            install_nvidia_graphics
+            ;;
+        *)
+            print "Skipping graphics driver installation."
+            ;;
+    esac
+}