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_homebrew_casks

@@ -0,0 +1,37 @@
+#! /usr/bin/env bash
+
+# Installs Homebrew Casks (GUI applications).
+
+set -o nounset
+set -o errexit
+set -o pipefail
+IFS=$'\n\t'
+
+# Ensure Homebrew is installed
+install_homebrew
+
+# Browsers
+brew install --cask eloston-chromium
+
+# Communication
+brew install --cask deepl
+brew install --cask element
+brew install --cask signal
+
+# Cloud & Sync
+brew install --cask nextcloud
+brew install --cask proton-drive
+brew install --cask proton-mail
+brew install --cask protonvpn
+
+# Development
+brew install --cask codex
+brew tap steipete/tap
+brew install --cask steipete/tap/codexbar
+brew install --cask nova
+brew install --cask transmit
+
+# Media & Utilities
+brew install --cask trimmy
+
+printf "\n✅ Homebrew Casks installation complete!\n"