When episodic_run_cron() detects new clusters or fails, it can
notify your team through one or more channels: ntfy, SMTP, sendmail,
Microsoft 365, Teams (Power Automate Workflow webhook), or Slack.
Notifications are configured in the instance YAML configuration file
(the same file EPISODIC_CONFIG points at), under a notifications
key. The notification settings are deliberately excluded from the
detection config_hash, so changing them never alters reproducibility
and secrets never reach the config_snapshot stored on each run.