List the recurring tasks scheduled for this session.

Use this tool to:
- See every scheduled task with its id, schedule, next fire time, and prompt
- Find the id to pass to `cron_delete`

In a session goal, list the goal's own cron tasks here. A task the goal waits for suspends the goal until it fires, and a goal's tasks are cancelled when it completes, blocks, or is cleared.

Do NOT use this tool as a poll loop while waiting — the harness resumes the session when a task fires.
