- Add new `doot-utils` crate with `xdg` module for consistent cross-platform directory resolution
- Replace `dirs` crate usage with `doot_utils::xdg` functions in cli, core, and lang crates
- Use XDG layout on all platforms (including macOS) for config, data, cache, and state directories
- Add home_dir(), config_home(), data_home(), cache_home(), and state_home() helpers
- Update dependencies to use doot-utils workspace reference
- Remove unused dirs and related crates from Cargo.lock
- Improve error handling in template rendering and package installation
- Add InstalledCache for package managers to reduce process spawning
- Optimize brew package installation with parallel fetching and sequential installing
- Fix path canonicalization in e2e tests for consistent symlink handling
- Add clippy allowance for large parser errors in doot-lang
