The kit's own component inventory — what /design shows, everywhere.

This is the canonical list. JobyKit.PageComponent.page_component/1 renders it directly rather than filtering the host's manifest, so the kit surface is genuinely identical across every consumer rather than identical by convention.

Why the host manifest doesn't decide this

It used to. Each install generated registrations for the kit's components into the host's DesignManifest, with previews in the host's DesignPreviews. Three things drifted from there, all of them observed in the fleet:

• Which components appear. Generated files are written once and never updated, so an app installed at 0.1 still advertised the 0.1 inventory. One app showed 8 of the 14 components its kit version shipped, with no indication the other 6 existed.
• What each preview renders. Host-owned previews were edited locally, so two apps on the same kit version demonstrated the same <.button> with different examples — one of them missing the icon-button case entirely.
• What the summary says. Same component, different prose per app.

A page that differs per app can't be the thing an agent learns once.

Hosts register their components; the kit registers the kit's.