feat(app): календарь выплат сеткой по месяцам

Месячная сетка с дивидендами, купонами, амортизациями и погашениями по дням, выплаченными и ожидаемыми, с сводкой за месяц и списком выплат выбранного дня. Раскладка без прокрутки страницы: высота ячеек подстраивается под окно, на широком экране список справа. Прежний список остался вторым режимом.

app/lib/features/income/calendar_tab.dart

@@ -1,24 +1,65 @@
 import 'package:decimal/decimal.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
-import 'package:go_router/go_router.dart';
 
 import '../../core/utils/ru_date.dart';
 import '../../core/widgets/async_value_view.dart';
 import '../../core/widgets/empty_state.dart';
 import '../../core/widgets/money_text.dart';
 import '../../core/widgets/section_card.dart';
-import '../portfolio/labels.dart' show formatQty;
+import 'calendar_grid.dart';
 import 'data/income_api.dart';
+import 'entry_row.dart';
 import 'labels.dart';
 import 'providers.dart';
 
-/// Календарь: every expected payment, month by month, each row carrying its [BasisChip].
+/// Календарь: the payments as a month grid (default) or as a list running forward.
+class IncomeCalendarTab extends ConsumerWidget {
+  const IncomeCalendarTab({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final view = ref.watch(calendarViewProvider);
+    return Column(
+      children: [
+        Padding(
+          padding: const EdgeInsets.fromLTRB(16, 8, 16, 0),
+          child: SegmentedButton<CalendarView>(
+            showSelectedIcon: false,
+            style: const ButtonStyle(visualDensity: VisualDensity.compact),
+            segments: const [
+              ButtonSegment(
+                value: CalendarView.month,
+                icon: Icon(Icons.calendar_month_outlined),
+                label: Text('Календарь'),
+              ),
+              ButtonSegment(
+                value: CalendarView.list,
+                icon: Icon(Icons.view_list_outlined),
+                label: Text('Список'),
+              ),
+            ],
+            selected: {view},
+            onSelectionChanged: (s) =>
+                ref.read(calendarViewProvider.notifier).state = s.first,
+          ),
+        ),
+        Expanded(
+          child: view == CalendarView.month
+              ? const IncomeMonthView()
+              : const _IncomeList(),
+        ),
+      ],
+    );
+  }
+}
+
+/// Every expected payment, month by month, each row carrying its [BasisChip].
 ///
 /// The total is deliberately paired with the by-basis split: adding «объявлено» and «по
 /// истории» into one number turns a guess into a promise.
-class IncomeCalendarTab extends ConsumerWidget {
-  const IncomeCalendarTab({super.key});
+class _IncomeList extends ConsumerWidget {
+  const _IncomeList();
 
   @override
   Widget build(BuildContext context, WidgetRef ref) {
@@ -207,64 +248,8 @@ class _MonthCard extends StatelessWidget {
         currency: 'RUB',
         style: Theme.of(context).textTheme.titleMedium,
       ),
-      child: Column(children: [for (final e in entries) _EntryRow(entry: e)]),
-    );
-  }
-}
-
-class _EntryRow extends StatelessWidget {
-  const _EntryRow({required this.entry});
-
-  final IncomeEntry entry;
-
-  @override
-  Widget build(BuildContext context) {
-    final theme = Theme.of(context);
-    final details = [
-      incomeKindLabel(entry.kind),
-      if (entry.qty != null && entry.perUnit != null)
-        '${formatQty(entry.qty!)} × ${MoneyText.format(entry.perUnit!, entry.currency)}',
-      if (entry.recordDate != null) 'отсечка ${ruDate(entry.recordDate!)}',
-      if (entry.taxWithheld != null)
-        'налог ${MoneyText.format(entry.taxWithheld!, entry.currency)}',
-    ].join(' · ');
-
-    return ListTile(
-      contentPadding: EdgeInsets.zero,
-      dense: true,
-      onTap: entry.instrumentId == null
-          ? null
-          : () => context.push('/portfolio/instrument/${entry.instrumentId}'),
-      title: Row(
-        children: [
-          Flexible(child: Text(entry.title, overflow: TextOverflow.ellipsis)),
-          const SizedBox(width: 8),
-          BasisChip(basis: entry.basis),
-        ],
-      ),
-      subtitle: Text(
-        '${entry.expectedDate == null ? 'дата неизвестна' : ruDate(entry.expectedDate!)} · $details',
-        style: theme.textTheme.bodySmall,
-      ),
-      trailing: Column(
-        mainAxisAlignment: MainAxisAlignment.center,
-        crossAxisAlignment: CrossAxisAlignment.end,
-        children: [
-          if (entry.amount != null)
-            MoneyText(
-              entry.amount!,
-              currency: entry.currency,
-              style: theme.textTheme.titleSmall,
-            ),
-          // no FX rate for the date ⇒ no rouble figure. An em dash, never 0 ₽.
-          if (entry.currency != 'RUB')
-            Text(
-              entry.amountRub == null
-                  ? '— ₽ (нет курса)'
-                  : MoneyText.format(entry.amountRub!, 'RUB'),
-              style: theme.textTheme.bodySmall,
-            ),
-        ],
+      child: Column(
+        children: [for (final e in entries) IncomeEntryRow(entry: e)],
       ),
     );
   }