Separate staff roles and protect message delivery with operator guides

src/display/demo_admin.py

@@ -23,7 +23,7 @@ async def demo_admin_features():
             first_name="Администратор",
             last_name="Системы"
         )
-        await UserService.set_admin(session, 123456789, True)
+        # Staff roles are assigned by a system administrator through /staff.
         print(f"✅ Создан администратор: {admin.first_name}")
         
         # Создаем тестовых пользователей