How an idea becomes validated specs, what lives where in your project, which skill to reach for, and what specfuse authoring upgrade will do to your files.
The handbooks and templates are the source of truth; this page is a map of them and links to each. It ships with the kit and specfuse authoring upgrade replaces it, so it describes the version you have installed. Skills are invoked as /specfuse-authoring:<name> once the plugin is installed.