feat: add release communications

docs/TASKS/release-communications/004-email-digest.md

@@ -0,0 +1,70 @@
+# Task: Release update email digest
+
+## Goal
+
+Add optional daily email digests for inactive users with unread release updates, plus a developer-operated manual email push for important published updates.
+
+## Feature Spec
+
+- `docs/FEATURES/release-communications.md`
+
+## Scope
+
+- Add configuration to enable or disable release update email digests.
+- Add persistence needed to rate-limit digest sends per user.
+- Send at most one digest per user per day.
+- Send only when the user has unread visible published release updates.
+- Send only when the user has not logged in or opened the app in at least 24 hours.
+- Initially target organization owners.
+- Use the existing email infrastructure.
+- Add a developer-only API endpoint to send an email announcement for a selected published release update.
+- Add a developer-only back-office button for sending the selected update by email.
+- Require confirmation before sending a manual push email.
+- Support a "send to me only" test mode.
+- Record manual push email metadata:
+  - sent by user id
+  - sent timestamp
+  - selected audience
+  - recipient count
+- Prevent accidental duplicate push sends unless the developer explicitly confirms a resend.
+- Keep user or organization email preferences out of this task.
+
+## Likely Files
+
+- `backend/src/Socialize.Api/Infrastructure/Emailer/**`
+- `backend/src/Socialize.Api/Modules/ReleaseCommunications/**`
+- `backend/src/Socialize.Api/Modules/Identity/**`
+- `backend/src/Socialize.Api/Modules/Organizations/**`
+- `frontend/src/features/release-communications/**`
+- `frontend/src/locales/en.json`
+- `frontend/src/locales/fr.json`
+- `backend/tests/Socialize.Tests/**`
+
+## Notes
+
+- This task may require tracking a user's last app activity timestamp if login timestamp alone is not enough.
+- Keep email copy concise and product-specific.
+- The digest should link back to the app's What’s New page.
+- Manual push emails should link directly to the selected update when possible.
+- Do not introduce a new email provider.
+
+## Validation
+
+```bash
+dotnet build backend/Socialize.slnx
+dotnet test backend/Socialize.slnx
+```
+
+## Done When
+
+- [x] Digest delivery is disabled unless explicitly configured.
+- [x] Eligible organization owners receive at most one digest per day.
+- [x] Digests are sent only when unread visible release updates exist.
+- [x] Active users are not emailed.
+- [x] Developers can manually send a published update email from the back office.
+- [x] Developers can send a manual update email to themselves as a test.
+- [x] Manual push sends require confirmation.
+- [x] Manual push sends record sender, timestamp, audience, and recipient count.
+- [x] Duplicate manual sends require explicit resend confirmation.
+- [x] Email delivery uses existing email infrastructure.
+- [x] Backend tests cover eligibility and rate limiting.