feat: add release communications

docs/TASKS/release-communications/001-backend-release-update-foundation.md

@@ -0,0 +1,71 @@
+# Task: Backend release update foundation
+
+## Goal
+
+Add the backend foundation for curated release update entries and per-user read state.
+
+## Feature Spec
+
+- `docs/FEATURES/release-communications.md`
+
+## Scope
+
+- Add a new FastEndpoints module under `backend/src/Socialize.Api/Modules/ReleaseCommunications`.
+- Add release update data entities and EF Core model configuration.
+- Add per-user release update read receipts.
+- Add enum/value support for:
+  - category: `Feature`, `Improvement`, `Fix`, `BreakingChange`
+  - importance: `Normal`, `Important`
+  - audience: `Everyone`, `OrganizationOwners`, `Developers`
+  - status: `Draft`, `Published`, `Archived`
+- Add `DbSet` entries and module configuration to `AppDbContext`.
+- Add current-user API endpoints:
+  - list visible published release updates
+  - get unread visible release updates
+  - mark one release update as read
+  - mark all visible release updates as read
+- Add developer API endpoints:
+  - list all release updates
+  - create draft release update
+  - get release update detail
+  - update draft release update
+  - publish release update
+  - archive release update
+- Enforce access rules:
+  - authenticated users can read only visible published updates
+  - only `Developer` users can manage update entries
+  - organization-owner audience only appears to users who own at least one organization
+  - developer audience only appears to `Developer` users
+- Keep commit import and email digest out of this task.
+
+## Likely Files
+
+- `backend/src/Socialize.Api/Data/AppDbContext.cs`
+- `backend/src/Socialize.Api/Modules/ReleaseCommunications/**`
+- `backend/tests/Socialize.Tests/**`
+
+## Notes
+
+- Treat release communications as global SaaS operator data, not workspace-owned workflow data.
+- Use FastEndpoints handlers and keep request/response records near handlers unless local module patterns suggest otherwise.
+- Use FluentValidation for non-trivial input.
+- Do not expose draft entries to non-developer users.
+- Do not expose commit metadata in user-facing DTOs.
+
+## Validation
+
+```bash
+dotnet build backend/Socialize.slnx
+dotnet test backend/Socialize.slnx
+```
+
+## Done When
+
+- [x] Developers can create draft release update entries.
+- [x] Developers can publish and archive release updates.
+- [x] Authenticated users can list visible published updates.
+- [x] Audience filtering is enforced.
+- [x] Users can mark one update read.
+- [x] Users can mark all visible updates read.
+- [x] Unread queries only count visible published updates.
+- [x] Backend tests cover access rules and read state.