feat: add optional shadowsocks and outline smart dialer config

Add support for optional Shadowsocks server and Outline Smart Dialer configuration.
- Make Shadowsocks server optional with enabled flag in config.
- Add Outline Smart Dialer YAML config endpoint for AWG fallback transport.
- Migrate to new outline import paths (golang.getoutline.org).
- Refactor ACME settings into separate config section.
- Add AWG hostname and mux_enabled options for flexible deployment.
- Generate random AWG obfuscation parameters in install script.
- Update README with dependencies table and new API endpoint.

refactor: rename project to shroud

Rename project from outline-distro to shroud for better branding.

- Update module path in go.mod from outline-distro to shroud.
- Rename binary, service file, and all installation paths.
- Update all import paths across internal packages.
- Add comprehensive README.md with usage and architecture docs.
- Update install script and systemd unit file for new naming.
- Update config example with new cert cache path.