Implement the stubbed NotificationsService methods backing the live notifications API

[RUKAYAT-CODER]

Overview

src/notifications/notifications.service.ts ends with a block commented // Stubs for other methods (to satisfy typecheck) containing send, sendTemplated, unsubscribe, findForUser, create, markRead, and markManyRead — returning null, [], undefined, or { data: [], total: 0 }. Every one of these is wired to a live route in NotificationsController: POST /notifications returns null, GET /notifications always reports an empty list, PATCH /notifications/:id/read marks nothing, and POST /notifications/unsubscribe/:userId unsubscribes no one. The notifications API is fully documented in Swagger and returns 200 for every call while doing nothing at all.

Specifications

Features:

• Every route exposed by NotificationsController is backed by a real implementation.
• Unimplemented functionality fails loudly rather than returning a success-shaped empty response.

Tasks:

• Implement create and send to persist a notification and dispatch it through the enabled channels using PreferencesService.
• Implement findForUser with pagination and ordering, returning the standard paginated envelope.
• Implement markRead and markManyRead with an ownership check on userId and a single bulk UPDATE.
• Implement unsubscribe against the preferences entity, honouring the eventType argument.
• Until each is implemented, throw NotImplementedException instead of returning an empty success value, so the gap is visible.
• Remove the any parameter types in favour of the existing DTOs.

Impacted Files:

• src/notifications/notifications.service.ts
• src/notifications/notifications.controller.ts
• src/notifications/preferences/preferences.service.ts

Acceptance Criteria

• Creating a notification then listing returns the created record.
• Marking a notification read persists and is reflected on the next read.
• Unsubscribing from an event type suppresses subsequent delivery for that type.
• No method in the service returns a hardcoded empty value.
• No _dto: any signatures remain.

[Chinonso-Peter]

@Chinonso-Peter has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Can i work on this issue

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Chinonso-Peter to this issue.

[drips-wave]

Congratulations, @Chinonso-Peter! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

🧑‍💻 @Chinonso-Peter: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊