## What changed
- Add `AppToolPolicyEvaluator::apply_app_enabled_state` and use it when
presenting app lists, building plugin context, and deciding whether app
instructions are available.
- Preserve each app's source state unless local or managed configuration
explicitly overrides it.
- Keep connector discovery and post-install refresh checks based on raw
accessibility rather than configured enablement.
## Testing
- Cover default enablement, per-app overrides, managed disablement, and
preservation of unconfigured source state.
GitOrigin-RevId: f1a62d55e7cc48b37113848e3baa0d69d8d9c8a8