Settings shell plugin: a pure composition face. It occupies sidebar.settings with the trigger chrome and modal settings panel, and declares the slots registrants fill: settings.trigger / settings.header / settings.close (chrome content), settings.section (one page per feature), and settings.onboarding (feature-owned overlays on the empty Hero). The shell ships no copy and reads no locale state — all text arrives from registrants (ui-settings-general owns chrome and General; features own their sections, rows, and onboarding overlays).

The shell supplies onboarding registrants only two navigation facts: whether the session surface is the empty Hero and an openSection(id) callback that opens the panel on a registered section. Registrants own capability readiness, dismissal, copy, and mutations; the shell therefore does not become a second configuration fact source.

Model Experience

None, as the settings shell serves browser UI composition; nothing here reaches a model request.

KV Cache effect

None; this package neither assembles nor sends a provider request.

Known Limitations and Deferred Work

Panel is browser-preference scope only — host-side settings surfaces (permission mode, tool-call mode) have no RPC backing yet; their skeletons live in ui-settings-general.