[Mobile] Implement push notifications via FCM/APNs

[Xoulomon]

Suggested Tier: Medium (150 pts)

Description:
Notify users of contribution deadlines and received payouts via native push, complementing the backend web-push service.

Tasks:

• Integrate expo-notifications with FCM (Android) and APNs (iOS)
• Register device push tokens with the backend notification service
• Route notification taps to the relevant group/contribution screen
• Add in-app notification preference toggles

Acceptance Criteria:

• A backend test notification is received and routes correctly on tap
• Disabling a category in-app suppresses it server-side

---

[code-0-stella]

@code-0-stella has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi, I'd like to work on this issue.

I've gone through the requirements, understand the problem, and have the skills needed to implement a solution.

Could you please assign it to me

ℹ️ Repo Maintainers: To accept this application, review their application or assign @code-0-stella to this issue.

[drips-wave]

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

🧑‍💻 @SIMPLE-koder: 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

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🤠 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 🌊

[drips-wave]

Congratulations, @cynthiaCODE01! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @cynthiaCODE01: 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 🌊

[drips-wave]

This issue is assigned to @cynthiaCODE01 via the Stellar Wave Program.

Other assignees have been removed. To reassign, please unassign the current contributor through Drips Wave first.