surface tmux teammates as a tile grid beside the lead (T-140)

TeamPanelHost wraps the lead Claude surface and, on TeamMemberJoined,
shows a resizable right pane with one tile per live teammate in a grid
that wraps 1->2->3 columns by count. Each tile renders the teammate's
conversation from its per-agent MessageBus channel; tiles drop on
TeamMemberLeft. With no team, only the lead shows (unchanged).

The Claude extension now starts a TeamObserver for the open workspace
(restarting as the project changes) — wiring T-139 into the running app.
ConversationView gains a wrapInSelectionArea flag so the whole grid
shares one selection area (nested SelectionAreas are illegal), letting a
drag-select span tiles. Member colours map to tile accents.

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

test/builtin/claude/team_panel_host_test.dart

@@ -0,0 +1,100 @@
+/// Widget tests for the teammate tile grid (T-140): tiles appear on
+/// TeamMemberJoined, disappear on TeamMemberLeft, and the lead shows
+/// alone when there's no team. Events are emitted directly into the
+/// fixture's event bus (the observer is exercised separately in
+/// team_observer_test.dart).
+library;
+
+import 'package:clide/builtin/claude/src/conversation_view.dart';
+import 'package:clide/builtin/claude/src/team_panel_host.dart';
+import 'package:clide/kernel/kernel.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import '../../helpers/kernel_fixture.dart';
+import '../../helpers/widget_harness.dart';
+
+Widget _lead() => const Center(child: Text('LEAD', textDirection: TextDirection.ltr));
+
+TeamMemberJoined _joined(String name, String pane, {String? color}) => TeamMemberJoined(
+      team: 'myteam',
+      agentId: '$name@myteam',
+      name: name,
+      agentType: 'researcher',
+      paneId: pane,
+      model: 'sonnet',
+      color: color,
+    );
+
+void main() {
+  late KernelFixture f;
+
+  setUp(() async => f = await KernelFixture.create());
+  tearDown(() => f.dispose());
+
+  Future<void> pumpHost(WidgetTester tester) async {
+    tester.view.physicalSize = const Size(1200, 700);
+    tester.view.devicePixelRatio = 1.0;
+    addTearDown(() {
+      tester.view.resetPhysicalSize();
+      tester.view.resetDevicePixelRatio();
+    });
+    await tester.pumpWidget(harness(f, TeamPanelHost(lead: _lead())));
+  }
+
+  Future<void> emit(WidgetTester tester, ClideEvent e) async {
+    f.services.events.emit(e);
+    await tester.pump();
+    await tester.pump();
+  }
+
+  testWidgets('lead shows alone with no team', (tester) async {
+    await pumpHost(tester);
+    expect(find.text('LEAD'), findsOneWidget);
+    expect(find.byType(ConversationView), findsNothing);
+  });
+
+  testWidgets('a teammate joining adds a tile; leaving removes it', (tester) async {
+    await pumpHost(tester);
+
+    await emit(tester, _joined('alice', '%5', color: 'blue'));
+    expect(find.text('alice'), findsOneWidget);
+    expect(find.byType(ConversationView), findsOneWidget);
+    expect(find.text('LEAD'), findsOneWidget); // lead still present beside the grid
+
+    await emit(tester, const TeamMemberLeft(team: 'myteam', agentId: 'alice@myteam', paneId: '%5'));
+    expect(find.text('alice'), findsNothing);
+    expect(find.byType(ConversationView), findsNothing);
+    expect(find.text('LEAD'), findsOneWidget); // back to lead-only
+  });
+
+  testWidgets('duplicate join is ignored', (tester) async {
+    await pumpHost(tester);
+    await emit(tester, _joined('alice', '%5'));
+    await emit(tester, _joined('alice', '%5'));
+    expect(find.text('alice'), findsOneWidget);
+  });
+
+  testWidgets('renders a tile per member as the team grows', (tester) async {
+    await pumpHost(tester);
+    await emit(tester, _joined('alice', '%5'));
+    await emit(tester, _joined('bob', '%6'));
+    await emit(tester, _joined('carol', '%7'));
+    await emit(tester, _joined('dave', '%8'));
+    for (final name in ['alice', 'bob', 'carol', 'dave']) {
+      expect(find.text(name), findsOneWidget);
+    }
+    expect(find.byType(ConversationView), findsNWidgets(4));
+  });
+
+  group('teamColor', () {
+    test('maps known names and falls back', () {
+      const fallback = Color(0xFF000000);
+      expect(teamColor('blue', fallback: fallback), const Color(0xFF61AFEF));
+      expect(teamColor('orange', fallback: fallback), const Color(0xFFD97757));
+      expect(teamColor('purple', fallback: fallback), teamColor('magenta', fallback: fallback));
+      expect(teamColor(null, fallback: fallback), fallback);
+      expect(teamColor('chartreuse', fallback: fallback), fallback);
+    });
+  });
+}