US-18 — Navigate between notification pages

## User story

As a notification author, I want to move between the notification list and the compose page so that I can easily review or create notifications.

## Acceptance scenarios

```gherkin
Feature: Navigate through Dispatcher

Scenario: Navigate to the compose page
Given the author is viewing all notifications
When the author selects "Compose new notification"
Then the compose page should be displayed

Scenario: Navigate to the notification list
Given the author is composing or viewing a notification
When the author selects "View all notifications"
Then the notification list should be displayed

Scenario: Identify the active navigation item
When the author opens a Dispatcher page
Then the corresponding navigation item should be visually identified as active
```

Start by locating the Dispatcher notification-list and compose-page entry points, then trace how navigation is currently wired. Verify both directions between the pages and the active navigation state against the three acceptance scenarios; done means each selection reaches the expected page and the corresponding item is visibly active.

Written by the indexing model from the issue text.