1## 1. Infrastructure23- [x] 1.1 Add `outbox` and `notification_preferences` tables (migration 0038)4- [x] 1.2 Add SMTP settings to config and deployment secrets56## 2. Notifier78- [x] 2.1 Emit assignment events to the outbox inside the assignment transaction9- [x] 2.2 Implement `cmd/notifier` worker that drains the outbox and sends email10- [x] 2.3 Skip self-assignments and opted-out recipients1112## 3. Preferences UI1314- [x] 3.1 Add per-project "Email me about assignments" toggle to project settings15- [x] 3.2 Add integration test covering opt-out