_list_jobs() only displayed job name, id, and schedule kind (e.g. "cron"),
omitting the actual timing and run state. The agent couldn't answer
"when does this run?" or "did it run?" even though CronSchedule and
CronJobState had all the data.
Now surfaces:
- Cron expression + timezone for cron jobs
- Human-readable interval for every jobs
- ISO timestamp for one-shot at jobs
- Enabled/disabled status
- Last run time + status (ok/error/skipped) + error message
- Next scheduled run time
Fixes#1496
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
