Flatten directory structure and update documentation

- Moved all files from mac_os/ subdirectory to repository root
- Updated README.adoc to reflect simplified architecture
- Updated QUICK_INSTALL.md with all current apps
- Added claude-cli to install.sh and bin/install_homebrew_formulas
- Repository now shows clean file structure without nested mac_os folder
- Documentation now accurately describes opinionated installer approach

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

lib/verifiers.sh

@@ -0,0 +1,81 @@
+#! /usr/bin/env bash
+
+# Defines verification/validation functions.
+
+# Label: Verify App Store Applications
+# Description: Check for missing App Store applications.
+verify_app_store_applications() {
+  local applications=""
+
+  printf "\n%s\n" "Checking App Store applications..."
+  applications="$(mas list)"
+
+  while read line; do
+    if [[ "$line" == "mas install"* ]]; then
+      application=$(printf "$line" | awk '{print $3}')
+      verify_listed_application "$application" "${applications[*]}"
+    fi
+  done < "$MAC_OS_PATH/bin/install_app_store"
+
+  printf "%s\n" "App Store check complete."
+}
+export -f verify_app_store_applications
+
+# Label: Verify Homebrew Casks
+# Description: Check for missing Homebrew casks.
+verify_homebrew_casks() {
+  local applications=""
+
+  printf "\nChecking Homebrew casks...\n"
+
+  applications="$(brew list --casks)"
+
+  while read line; do
+    if [[ "$line" == "brew install --cask"* ]]; then
+      application=$(printf "%s" "$line" | awk '{print $5}')
+      verify_listed_application "$application" "${applications[*]}"
+    fi
+  done < "$MAC_OS_PATH/bin/install_homebrew_casks"
+
+  printf "%s\n" "Homebrew cask check complete."
+}
+export -f verify_homebrew_casks
+
+# Label: Verify Homebrew Formulas
+# Description: Check for missing Homebrew formulas.
+verify_homebrew_formulas() {
+  local applications=""
+
+  printf "Checking Homebrew formulas...\n"
+
+  applications="$(brew list --formulae)"
+
+  while read line; do
+    if [[ "$line" == "brew install"* ]]; then
+      application=$(printf "%s" "$line" | awk '{print $3}')
+
+      # Exception: "gpg" is the binary but is listed as "gnugp".
+      if [[ "$application" == "gpg" ]]; then
+        application="gnupg"
+      fi
+
+      verify_listed_application "$application" "${applications[*]}"
+    fi
+  done < "$MAC_OS_PATH/bin/install_homebrew_formulas"
+
+  printf "%s\n" "Homebrew formula check complete."
+}
+export -f verify_homebrew_formulas
+
+# Label: Verify Listed Application
+# Description: Verify listed application exists.
+# Parameters: $1 (required): Current application, $2 (required): Application list.
+verify_listed_application() {
+  local application="$1"
+  local applications="$2"
+
+  if [[ "${applications[*]}" != *"$application"* ]]; then
+    printf "%s\n" " - Missing: $application"
+  fi
+}
+export -f verify_listed_application