[TODO Import][Server][Backlog] Push notifications module and integration

[ferneediaz]

Imported from server/TODO.md.

Kanban

• Column: Backlog
• Area: Server

📋 TODO - Push Notifications (MEDIUM PRIORITY)

Browser push notifications for key events.

Task Breakdown:

1. Prisma Schema Updates

• Add PushSubscription model (id, userId, endpoint, p256dh, auth, createdAt)
• Run migration
• Success Criteria: Schema compiles ✅

2. Push Service

• Create notifications/ module
• subscribe(userId, subscription) — Store push subscription
• unsubscribe(userId, endpoint) — Remove push subscription
• sendNotification(userId, title, body, data?) — Send push to user
• Generate VAPID keys for web push
• Success Criteria: Push notifications delivered ✅

3. Integration Points

• Notify on: match found, battle invite received, friend request, clan challenge
• POST /api/notifications/subscribe — Register push subscription
• DELETE /api/notifications/subscribe — Unregister
• Success Criteria: Notifications fire for all triggers ✅

4. Tests

• Subscription storage tests
• Notification delivery tests
• Success Criteria: All notification tests passing ✅

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