Notifications Screen

Lists all notifications with type-coded icons and colors, an unread-count chip in the header, a 'Mark all as read' action, and per-row tap to navigate or open detail.

1. Watches notificationsControllerProvider for state.
2. Pull-to-refresh calls refresh.
3. Row tap fires markAsRead and navigates based on type / template (orders → /orders/:id; messages → /messages).
4. 'Mark all read' calls markAllAsRead.

• Empty state renders illustration + 'No notifications yet'.
• Type colors come from the model extension — keep palette in sync with theming.
• Long-press on a row reveals a dismiss action that calls deleteNotification (local-only).

• lib/src/features/shared/notifications/views/notifications_screen.dart
• lib/src/features/shared/notifications/views/notification_detail_screen.dart

The unread badge consumers (e.g. home bell icon) should ref.watch the state.unreadCount derived getter, not the full list.