Enhancement

• Add ai_summary parameter in task_setting to enable AI-generated summary and key information for the task. Available in POST /v1/sign_tasks, POST /v1/sign_tasks/quick_create, PUT /v1/sign_tasks, and PUT /v1/sign_tasks/update_settings APIs.
• Expose ai_summary in task_setting of the GET /v1/sign_tasks (Get a task) API response.