Function remind_due 

pub async fn remind_due(pool: &PgPool) -> AppResult<u64>

Reminds the managers of every group whose access review is due (the hourly housekeeping): once when the review becomes due and again after each further interval without one. A group without managers reminds the active administrators.

Invariants

• Permission: none; a background task, not an actor.
• Locks: the policy row of the group (FOR UPDATE), so two servers do not both remind.
• Data: sets project_policies.review_reminded_at.
• Audit: project.review_reminder per group.
• Notifications: an access_alert to each manager (not mutable); webhooks: none.
• Atomic: one transaction per group.