feat(app): offline-кэш на остальных экранах — фаза 5

accounts, cashflow, categories, goals, income, portfolio (+instrument),
rebalance, tax, rules переведены на Cached<T> по контракту
docs/ai/offline-cache.md. Общие/второстепенные селекторы (scopesProvider,
categoriesListProvider и т.п.) оставлены как есть — не основной контент
экрана. sync_page.dart и settings_page.dart не тронуты (первый — заменён
health-page отдельно, второй — чистые действия без списка для баннера).

app/test/portfolio_test.dart

@@ -1,6 +1,9 @@
 import 'package:fintracker_api/fintracker_api.dart';
+import 'package:fintracker_app/core/cache/cached.dart';
 import 'package:fintracker_app/core/widgets/money_text.dart';
 import 'package:fintracker_app/features/portfolio/allocation_tab.dart';
+import 'package:fintracker_app/features/portfolio/benchmarks_card.dart';
+import 'package:fintracker_app/features/portfolio/data/benchmarks_api.dart';
 import 'package:fintracker_app/features/portfolio/holdings_tab.dart';
 import 'package:fintracker_app/features/portfolio/labels.dart';
 import 'package:fintracker_app/features/portfolio/providers.dart';
@@ -82,13 +85,16 @@ void main() {
     await pumpTall(tester, _wrap(
       const HoldingsTab(),
       [
-        portfolioSummaryProvider.overrideWith((ref) => summary()),
-        valueSeriesProvider.overrideWith((ref) => const <ValueDay>[]),
-        portfolioReturnsProvider.overrideWith((ref) => const <ReturnsOut>[]),
-        holdingsProvider.overrideWith((ref) => [
+        portfolioSummaryProvider.overrideWith((ref) => Cached(summary())),
+        valueSeriesProvider.overrideWith((ref) => const Cached(<ValueDay>[])),
+        portfolioReturnsProvider.overrideWith((ref) => const Cached(<ReturnsOut>[])),
+        holdingsProvider.overrideWith((ref) => Cached([
               holding(id: 1, ticker: 'GAZP', valueRub: '11000', weight: '1'),
               holding(id: 2, ticker: 'SIBN6P4', priceStatus: 'missing'),
-            ]),
+            ])),
+        // HoldingsTab embeds BenchmarksCard, which watches this too — leaving it out would
+        // fall through to the real apiProvider (see docs/ai/offline-cache.md).
+        benchmarkRowsProvider.overrideWith((ref) => const Cached(<BenchmarkRow>[])),
       ],
     ));
 
@@ -105,10 +111,11 @@ void main() {
     await pumpTall(tester, _wrap(
       const HoldingsTab(),
       [
-        portfolioSummaryProvider.overrideWith((ref) => summary()),
-        valueSeriesProvider.overrideWith((ref) => const <ValueDay>[]),
-        portfolioReturnsProvider.overrideWith((ref) => const <ReturnsOut>[]),
-        holdingsProvider.overrideWith((ref) => const <HoldingOut>[]),
+        portfolioSummaryProvider.overrideWith((ref) => Cached(summary())),
+        valueSeriesProvider.overrideWith((ref) => const Cached(<ValueDay>[])),
+        portfolioReturnsProvider.overrideWith((ref) => const Cached(<ReturnsOut>[])),
+        holdingsProvider.overrideWith((ref) => const Cached(<HoldingOut>[])),
+        benchmarkRowsProvider.overrideWith((ref) => const Cached(<BenchmarkRow>[])),
       ],
     ));
 
@@ -120,7 +127,7 @@ void main() {
     await pumpTall(tester, _wrap(
       const AllocationTab(),
       [
-        allocationProvider.overrideWith((ref) => [
+        allocationProvider.overrideWith((ref) => Cached([
               AllocationBucket(
                 bucket: 'share',
                 dimension: AllocationDimension.assetClass,
@@ -135,7 +142,7 @@ void main() {
                 valueRub: '5700',
                 weight: '0.3413',
               ),
-            ]),
+            ])),
       ],
     ));
 

app/test/rules_page_test.dart

@@ -1,4 +1,5 @@
 import 'package:fintracker_api/fintracker_api.dart';
+import 'package:fintracker_app/core/cache/cached.dart';
 import 'package:fintracker_app/features/rules/providers.dart';
 import 'package:fintracker_app/features/rules/rules_page.dart';
 import 'package:flutter/material.dart';
@@ -10,8 +11,8 @@ void main() {
     await tester.pumpWidget(
       ProviderScope(
         overrides: [
-          rulesListProvider.overrideWith((ref) => const <RuleOut>[]),
-          rulesStaleProvider.overrideWith((ref) => const <RuleOut>[]),
+          rulesListProvider.overrideWith((ref) => const Cached(<RuleOut>[])),
+          rulesStaleProvider.overrideWith((ref) => const Cached(<RuleOut>[])),
         ],
         child: const MaterialApp(home: RulesPage()),
       ),