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>

bin/install_dev_tools

@@ -0,0 +1,13 @@
+#! /usr/bin/env bash
+
+# Installs development tooling requirements.
+
+printf "%s\n" "Installing Xcode CLI tools..."
+xcode-select --install
+
+printf "%s\n" "💡 ALT+TAB to view and accept Xcode license window."
+read -p "Have you completed the Xcode CLI tools install (y/n)? " xcode_response
+if [[ "$xcode_response" != "y" ]]; then
+  printf "%s\n" "ERROR: Xcode CLI tools must be installed before proceeding."
+  exit 1
+fi