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/lib/features/goals/goals_page.dart

@@ -1,9 +1,11 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
+import '../../core/cache/cached.dart';
 import '../../core/utils/json.dart';
 import '../../core/widgets/async_value_view.dart';
 import '../../core/widgets/empty_state.dart';
+import '../../core/widgets/stale_banner.dart';
 import 'data/goals_api.dart';
 import 'goal_card.dart';
 import 'goal_edit_dialog.dart';
@@ -78,6 +80,13 @@ class _GoalsPageState extends ConsumerState<GoalsPage> {
   @override
   Widget build(BuildContext context) {
     final goals = ref.watch(goalsProvider);
+    // Every card's own progress fetch counts toward the one banner too — a fresh list with a
+    // stale progress card is still an offline dashboard, just not a visibly empty one.
+    final goalIds = [for (final g in goals.valueOrNull?.data ?? const <Goal>[]) g.id];
+    final stale = oldestFetch([
+      goals.valueOrNull?.fetchedAt,
+      for (final id in goalIds) ref.watch(goalProgressProvider(id)).valueOrNull?.fetchedAt,
+    ]);
 
     return Scaffold(
       appBar: AppBar(
@@ -105,12 +114,14 @@ class _GoalsPageState extends ConsumerState<GoalsPage> {
         child: AsyncValueView(
           value: goals,
           onRetry: () => ref.invalidate(goalsProvider),
-          data: (all) {
+          data: (cached) {
+            final all = cached.data;
             final rows = _showArchived ? all : all.where((g) => !g.archived).toList();
             if (rows.isEmpty) {
               return ListView(
                 padding: const EdgeInsets.all(16),
                 children: [
+                  if (stale != null) StaleBanner(fetchedAt: stale),
                   const SizedBox(height: 48),
                   EmptyState(
                     icon: Icons.flag_outlined,
@@ -125,6 +136,7 @@ class _GoalsPageState extends ConsumerState<GoalsPage> {
             return ListView(
               padding: const EdgeInsets.fromLTRB(16, 16, 16, 88),
               children: [
+                if (stale != null) StaleBanner(fetchedAt: stale),
                 for (final g in rows)
                   Padding(
                     padding: const EdgeInsets.only(bottom: 12),