add Claude meta sidebar — activity + team roster

An always-pickable left-panel tab. Shows Claude activity read from
~/.claude/stats-cache.json (latest day's messages/sessions/tool-calls +
lifetime totals, polled) and, when a tmux agent team is running, a roster
of its members (colour · name · agent type · model) from the observer's
join/left events — nothing re-tailed here.

Scoped down from the original ticket: the account/team token budget isn't
programmatically exposed under subscription auth (TUI-only; upstream
#44328) and live per-member status needs the teammate status stream wired
onto the bus — filed as T-158 and T-157 respectively.

T-141.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

test/builtin/claude/claude_meta_sidebar_test.dart

@@ -0,0 +1,66 @@
+import 'package:clide/builtin/claude/src/claude_meta_sidebar.dart';
+import 'package:clide/builtin/claude/src/claude_stats.dart';
+import 'package:clide/kernel/kernel.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import '../../helpers/kernel_fixture.dart';
+import '../../helpers/widget_harness.dart';
+
+void main() {
+  late KernelFixture f;
+  setUp(() async => f = await KernelFixture.create());
+  tearDown(() => f.dispose());
+
+  ClaudeMetaSidebar sidebar({ClaudeStats stats = const ClaudeStats()}) => ClaudeMetaSidebar(
+        statsLoader: () async => stats,
+        pollInterval: Duration.zero,
+      );
+
+  testWidgets('shows the latest day + lifetime activity from stats', (tester) async {
+    const stats = ClaudeStats(
+      lastComputed: '2026-05-22',
+      daily: [
+        DailyActivity(date: '2026-05-01', messageCount: 100, sessionCount: 2, toolCallCount: 30),
+        DailyActivity(date: '2026-05-22', messageCount: 250, sessionCount: 5, toolCallCount: 80),
+      ],
+    );
+    await tester.pumpWidget(harness(f, sidebar(stats: stats)));
+    await tester.pumpAndSettle();
+
+    expect(find.text('2026-05-22'), findsOneWidget);
+    expect(find.text('250 msgs  ·  5 sessions  ·  80 tools'), findsOneWidget);
+    expect(find.text('Lifetime: 350 msgs over 2 days'), findsOneWidget);
+    expect(find.text('No team active.'), findsOneWidget);
+  });
+
+  testWidgets('adds and removes team members from the roster', (tester) async {
+    await tester.pumpWidget(harness(f, sidebar()));
+    await tester.pumpAndSettle();
+
+    f.services.events.emit(const TeamMemberJoined(
+      team: 't',
+      agentId: 'a1',
+      name: 'Scout',
+      agentType: 'explorer',
+      paneId: '%1',
+      model: 'claude-opus-4-7',
+      color: 'blue',
+    ));
+    await tester.pump();
+    await tester.pump();
+    expect(find.text('Scout'), findsOneWidget);
+    expect(find.text('explorer  ·  opus 4.7'), findsOneWidget);
+
+    f.services.events.emit(const TeamMemberLeft(team: 't', agentId: 'a1', paneId: '%1'));
+    await tester.pump();
+    await tester.pump();
+    expect(find.text('Scout'), findsNothing);
+    expect(find.text('No team active.'), findsOneWidget);
+  });
+
+  testWidgets('degrades to a no-activity message with empty stats', (tester) async {
+    await tester.pumpWidget(harness(f, sidebar()));
+    await tester.pumpAndSettle();
+    expect(find.text('No activity recorded yet.'), findsOneWidget);
+  });
+}

test/builtin/claude/claude_stats_test.dart

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+import 'dart:convert';
+
+import 'package:clide/builtin/claude/src/claude_stats.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('parseClaudeStats', () {
+    test('parses daily activity, latest day, and lifetime totals', () {
+      final json = jsonEncode({
+        'version': 3,
+        'lastComputedDate': '2026-05-22',
+        'dailyActivity': [
+          {'date': '2026-05-01', 'messageCount': 100, 'sessionCount': 2, 'toolCallCount': 30},
+          {'date': '2026-05-22', 'messageCount': 250, 'sessionCount': 5, 'toolCallCount': 80},
+        ],
+      });
+      final s = parseClaudeStats(json);
+      expect(s.lastComputed, '2026-05-22');
+      expect(s.activeDays, 2);
+      expect(s.latest!.date, '2026-05-22'); // most recent, not last in array
+      expect(s.latest!.messageCount, 250);
+      expect(s.lifetimeMessages, 350);
+      expect(s.lifetimeSessions, 7);
+      expect(s.lifetimeToolCalls, 110);
+    });
+
+    test('picks the latest day regardless of array order', () {
+      final json = jsonEncode({
+        'dailyActivity': [
+          {'date': '2026-05-22', 'messageCount': 1, 'sessionCount': 1, 'toolCallCount': 1},
+          {'date': '2026-05-02', 'messageCount': 9, 'sessionCount': 9, 'toolCallCount': 9},
+        ],
+      });
+      expect(parseClaudeStats(json).latest!.date, '2026-05-22');
+    });
+
+    test('missing counts default to zero', () {
+      final json = jsonEncode({
+        'dailyActivity': [
+          {'date': '2026-05-22'},
+        ],
+      });
+      final s = parseClaudeStats(json);
+      expect(s.latest!.messageCount, 0);
+      expect(s.lifetimeToolCalls, 0);
+    });
+
+    test('malformed or empty input yields empty stats', () {
+      expect(parseClaudeStats('{ not json').daily, isEmpty);
+      expect(parseClaudeStats('[]').daily, isEmpty);
+      expect(parseClaudeStats('{}').latest, isNull);
+    });
+  });
+}