crux-init

Set up CRUX Compress in the current project from this plugin. Copies the CRUX specification to CRUX.md, adds or refreshes the <CRUX> block in AGENTS.md, records the version in .crux/crux.json, and optionally creates the memory system scaffolding. Use when CRUX.md is missing, after updating the plugin, or when the user asks to install, initialise, or update CRUX in a project.