refactor!: markNotificationAsRead takes notification_id + kind

[aeharding]

Summary

The current markNotificationAsRead({ notification, read }) signature forces callers to hand in a full Notification object even though every provider only consumes kind and id. Callers who only know "I want to mark PM #42 read" have to fabricate a Notification with bogus creator_id, published_at, etc. just to satisfy the type.

Change the signature to the honest minimum:

markNotificationAsRead({ kind: NotificationDataType; notification_id: number; read: boolean })

All three providers' implementations only touch those two fields, so it's a pure simplification — no behavior change.

Test plan

• pnpm test:types clean
• pnpm test — 19 / 19 pass
• pnpm format:check clean

Breaking

Consumers using client.markNotificationAsRead({ notification, read }) need to switch to { kind: notification.kind, notification_id: notification.id, read }. (Voyager PR follow-up.)