Update code using deprecated ZenStack v2 APIs #63
Description
Update all application code that uses deprecated v2 APIs to their v3 equivalents.
Known changes:
- `withPolicy` → `enhance`
- Any other deprecated API calls identified during the breaking changes review
Acceptance Criteria:
- No references to deprecated v2 APIs remain in the codebase
- All API calls use v3 equivalents
- TypeScript compilation passes with no type errors
Part of the ZenStack v2 → v3 upgrade.