- Introduced a new `PrivilegesModule` to manage user privileges and access control.
- Added `RequirePrivilege` decorator to enforce privilege checks on controller handlers.
- Implemented `PrivilegesGuard` to handle authorization based on user privileges.
- Created database migrations for `privileges`, `privilege_keys`, and `privilege_details` tables.
- Updated user model to include `is_superadmin` field for enhanced access control.
- Added unit tests for the new privileges functionality and guards to ensure correct behavior.
