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>

Rakefile

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+require "git/lint/rake/register"
+require "rubocop/rake_task"
+
+Git::Lint::Rake::Register.call
+RuboCop::RakeTask.new
+
+desc "Run code quality checks"
+task quality: %i[git_lint rubocop]
+
+task default: :quality