Implement SUPER_ADMIN permission checks in user management

- Added validation to ensure that only existing SUPER_ADMIN users can grant or modify SUPER_ADMIN permissions.
- Updated the user management page to reflect that both SUPER_ADMIN and COMPANY_ADMIN can access the user permissions, while COMPANY_ADMIN cannot grant SUPER_ADMIN rights.
- Enhanced the user authorization modal to prevent COMPANY_ADMIN from changing SUPER_ADMIN permissions, ensuring proper access control.

These changes improve the security and integrity of user role management within the application.

frontend/components/admin/UserFormModal.tsx

@@ -459,6 +459,7 @@ export function UserFormModal({ isOpen, onClose, onSuccess, editingUser }: UserF
                         value={formData.userId}
                         onChange={(e) => handleInputChange("userId", e.target.value)}
                         onKeyDown={handleKeyDown}
+                        autoComplete="off"
                         className="flex-1"
                       />
                       <Button
@@ -511,6 +512,7 @@ export function UserFormModal({ isOpen, onClose, onSuccess, editingUser }: UserF
                     value={formData.userPassword}
                     onChange={(e) => handleInputChange("userPassword", e.target.value)}
                     onKeyDown={handleKeyDown}
+                    autoComplete="new-password"
                     className="pr-10"
                   />
                   <Button