Let users search files in folders they explicitly choose.
Acceptance criteria:
- Native folder picker and security-scoped bookmarks survive restart.
- Revoked access has a recoverable UI state.
- Bounded background indexing with exclusions and cancellation.
- Open and reveal use native Craft interfaces.
Blocked by: reusable security-scoped bookmark support and signed sandbox qualification.
Source: https://developer.apple.com/documentation/security/protecting-user-data-with-app-sandbox