feat(app): экраны импорта отчётов, целей, доходов, ребалансировки, налогов и бенчмарков

Импорт (/imports, /instruments/pending) и фаза 4 (/goals, /income,
/rebalance, /tax, аналитика-хаб с benchmarks_card) — по
docs/ai/import-contract.md и docs/ai/phase4-contract.md. file_picker для
загрузки отчёта.

app/test/app_shell_test.dart

@@ -3,11 +3,11 @@ import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
-  Widget wrap(double width) {
+  Widget wrap(double width, {String location = '/'}) {
     return MediaQuery(
       data: MediaQueryData(size: Size(width, 800)),
       child: MaterialApp(
-        home: AppShell(location: '/', child: Container()),
+        home: AppShell(location: location, child: Container()),
       ),
     );
   }
@@ -23,4 +23,22 @@ void main() {
     expect(find.byType(NavigationBar), findsOneWidget);
     expect(find.byType(NavigationRail), findsNothing);
   });
+
+  testWidgets('the resolve screen keeps Импорт selected', (tester) async {
+    await tester.pumpWidget(wrap(1280, location: '/instruments/pending'));
+    final rail = tester.widget<NavigationRail>(find.byType(NavigationRail));
+    expect(
+      (rail.destinations[rail.selectedIndex!].label as Text).data,
+      'Импорт',
+    );
+  });
+
+  testWidgets('a nested route keeps its own section selected', (tester) async {
+    await tester.pumpWidget(wrap(1280, location: '/portfolio/instrument/311'));
+    final rail = tester.widget<NavigationRail>(find.byType(NavigationRail));
+    expect(
+      (rail.destinations[rail.selectedIndex!].label as Text).data,
+      'Портфель',
+    );
+  });
 }