Daily and weekly email digest #48

Problem

Needly has no re-engagement path. A user who stops visiting for a week has no reason to come back, and Needly has no way to tell them something needs them.

Email is also the only channel that reaches somebody who has not installed the PWA, linked Slack, or kept a tab open.

Scope

A scheduled digest, sent at a user-chosen time in the user's timezone.

Content: what needs you now, grouped by action type; what became at risk since the last digest; what you cleared; what is waiting on others.

Acceptance criteria

• Frequency configurable: daily, weekly, or off, with a per-user send time and timezone
• Digest is skipped entirely when there is nothing to report, rather than sending an empty message
• Every action deep-links to Needly, and Snooze and Archive work from the email through signed one-click links
• One-click unsubscribe honouring List-Unsubscribe
• Plain-text alternative alongside HTML
• Uses the verified email already captured during GitHub sign-in
• Bounce and complaint handling disables delivery to failing addresses

Notes

The skip-when-empty rule is what separates a digest people keep from one they filter. It is not optional.