Deliver a persistent Craft palette that opens applications from keyboard search.
Acceptance criteria:
- Real key press while another app is active opens the existing window and focuses search.
- Conflict errors are visible; repeated activation does not create extra windows.
- Search, arrows, Return and Escape work after repeated hide/show cycles.
- Test on the signed sandboxed artifact.
Blocked by: reusable native model support in Stacks core.
Sources: https://github.com/craft-native/craft and docs/planning/research.md