- Introduce `hasPermission` method in `subusers_o` for permission checks tied to customer context.
- Update `/subusers/me` route to return subuser grants with normalized permissions and metadata.
- Add `get_subuser_customer_number_target` in `authentication` to resolve customer context from request headers.
- Refactor route-level permission checks to handle subuser grants dynamically.
- Introduce CLI test scripts for subuser grants and permission node mappings.
- Add test coverage for subuser grants and permission nodes in new test classes.