Steno: DSH Message Inline Shortcut Expansion Plugin

Steno is a DSH plugin designed to quickly replace frequently used commands using `#tag`. It supports multiple YAML library management, aliases, variable placeholders (e.g., `{{name:default}}`), and recursive expansion with cycle and depth limits. Tags inside code blocks are protected. The plugin provides a CLI tool that requires Node.js >= 22.18; after initialization, users can use it by editing the configuration file.