Integration Test: Full Bottom Nav Accessibility

This is an integration test not a unit widget test — set it up in the integration_test/ directory using flutter_test's IntegrationTestWidgetsFlutterBinding.ensureInitialized(). Build a complete minimal app fixture with GoRouter (5 routes, stub screens) and ProviderScope. Tab traversal without swipe is the key requirement: use tester.tap(find.byKey(tabKey)) for each tab, never tester.drag(). The 'selected' announcement requirement maps to Flutter's NavigationBar semantics behavior — ensure AccessibleBottomNavBar sets selected: true on the active NavigationDestination or equivalent and that the Semantics.label includes 'selected'.

For the notification badge Semantics label test, override notificationCountProvider to return 3 and assert the full label string. Keep screen stubs minimal (just a Text widget per screen) to avoid test complexity. Run this test in CI using `flutter test integration_test/` with no physical device requirement.

Use flutter_test integration test infrastructure (not patrol or another third-party framework unless already in use). Set up a full app with GoRouter and ProviderScope with all required Riverpod overrides (notification count, auth, etc.). Iterate through all 5 tabs: tap each, pump, assert route, assert Semantics. For notification badge, inject count = 3 via ProviderScope override and assert the Notifications tab label contains '3'.

For active state, after tapping each tab assert that tab's Semantics includes 'selected' and the others do not. Run AccessibilityAuditRunner.audit(tester) once after the full nav is stable. Ensure no real Supabase/BankID/Vipps calls occur by overriding all remote providers.