- Move admin modules list from is_admin method to ADMIN_MODULES constant
- Rename is_admin() to isAdmin() following CodeIgniter naming conventions
- Rename can_modify_employee() to canModifyEmployee() following conventions
- Update all callers in Employees controller and tests
- Non-admin employees can no longer view/modify admin accounts
- Non-admin employees can no longer delete admin accounts
- Non-admin employees can only grant permissions they themselves have
- Added is_admin() and can_modify_employee() methods to Employee model
- Prevents privilege escalation via permission grants
Add tests for BOLA fix and permission delegation
- EmployeeTest: Unit tests for is_admin() and can_modify_employee() methods
- EmployeesControllerTest: Test cases for authorization checks (integration tests require DB)
- ReportsControllerTest: Test validating the constructor redirect fix pattern
Fix return type error in Employees controller
Use $this->response->setJSON() instead of echo json_encode() + return
to properly satisfy the ResponseInterface return type.
