Module components 

VAPP-203: install checks every template the way the renderer will. Each template’s components go through the reducer (reduce_surface: unknown components, missing or wrong props, child ids that name nothing, cycles, slots, styles), so a package that would render broken never installs. A reducer issue (keyed by a component id) becomes a JSON pointer: the component’s own entry, or, for an id no component has, every place that names it (children/<j>, children/componentId, slots/<name>). The twin of src/host/components.ts (fixtures/host-router.json).

Functions

validate_package_components

VAPP-203: every template’s components, reduced as the host will render them against view (the core plus the extensions the host has definitions for). An unsupported catalog is reported elsewhere. A catalog or declared extension view does not know leaves its component names open (an unknown component is not reported); every other check still holds.