Task: Implement a Notification Service

You are working on a Node.js application that sends email and push notifications. The current implementation uses a mix of global variables and ad hoc error handling. Your job is to implement a clean NotificationService in Effect TypeScript.

Project Context

The project is located at /workspace/scenario-1-project/. It already has effect and @effect/platform-node installed. There is a src/notifications/ directory with a stub file.

Requirements

Implement a NotificationService that:

1. Sends email notifications using a hypothetical EmailClient dependency
2. Sends push notifications using a hypothetical PushClient dependency
3. Exposes a single send(notification: Notification) => Effect method
4. Supports two notification types: EmailNotification and PushNotification
5. Models failures explicitly — differentiate between EmailDeliveryError and PushDeliveryError
6. Can be tested without real email or push infrastructure

What to Produce

Write the following files (create them at the paths shown):

• /workspace/scenario-1-project/src/notifications/NotificationService.ts — the service definition and live layer
• /workspace/scenario-1-project/src/notifications/errors.ts — error types
• /workspace/scenario-1-project/src/notifications/models.ts — domain model types
• /workspace/scenario-1-project/src/notifications/index.ts — barrel export

The existing stub at /workspace/scenario-1-project/src/notifications/stub.ts shows the current imperative approach (for reference only).

Constraints

• Do not use any external runtime execution inside the service implementation
• All dependencies must flow through the layer system
• The send method signature must not carry extra environment requirements beyond what the layer provides
• Use TypeScript