Bring users back before they're gone.

When last_active_at crosses 30 days, fire a reactivation series — email plus WhatsApp escalation. Stops as soon as the user comes back.

• Trigger: last_active_at older than 30 days
• Channel: Email reactivation series + WhatsApp
• Goal: last_active_at updated within X days
• Variations: feature-led, founder note, win-back discount