route Claude transcript content through the MessageBus

The Claude pane owned a TranscriptReader directly via the controller.
Insert a TranscriptPublisher that tails the transcript and republishes
each ConversationItem onto the kernel MessageBus; the view's controller
subscribes through ConversationController.fromBus. The subscription is
attached before the reader's first poll, so the initial tail isn't
missed on the broadcast bus.

This decouples reading from rendering: the team work (T-139/T-140) can
run one observer that publishes per-agent channels while the lead tile
and each teammate tile subscribe independently.

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

test/builtin/claude/conversation_view_test.dart

@@ -8,7 +8,9 @@ import 'dart:async';
 
 import 'package:clide/builtin/claude/src/conversation_controller.dart';
 import 'package:clide/builtin/claude/src/conversation_view.dart';
+import 'package:clide/builtin/claude/src/transcript_publisher.dart';
 import 'package:clide/builtin/claude/src/transcript_reader.dart';
+import 'package:clide/kernel/src/events/message_bus.dart';
 import 'package:clide/widgets/widgets.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -78,6 +80,35 @@ void main() {
     });
   });
 
+  group('ConversationController.fromBus', () {
+    test('consumes items published on its publisher/channel', () async {
+      final bus = MessageBus();
+      addTearDown(bus.dispose);
+      final c = ConversationController.fromBus(messages: bus);
+      addTearDown(c.dispose);
+
+      bus.publish(ClaudeConversation.publisher, ClaudeConversation.leadChannel, {ClaudeConversation.itemKey: _user('hi')});
+      bus.publish(ClaudeConversation.publisher, ClaudeConversation.leadChannel, {ClaudeConversation.itemKey: _asst('hello')});
+      await Future<void>.delayed(const Duration(milliseconds: 20));
+
+      expect(c.items, hasLength(2));
+      expect(c.items.first, isA<UserMessage>());
+    });
+
+    test('ignores other publishers and channels', () async {
+      final bus = MessageBus();
+      addTearDown(bus.dispose);
+      final c = ConversationController.fromBus(messages: bus);
+      addTearDown(c.dispose);
+
+      bus.publish('someone.else', ClaudeConversation.leadChannel, {ClaudeConversation.itemKey: _user('nope')});
+      bus.publish(ClaudeConversation.publisher, 'conversation/other', {ClaudeConversation.itemKey: _user('nope')});
+      await Future<void>.delayed(const Duration(milliseconds: 20));
+
+      expect(c.items, isEmpty);
+    });
+  });
+
   group('ConversationView', () {
     late KernelFixture f;
     setUp(() async => f = await KernelFixture.create());

test/builtin/claude/transcript_publisher_test.dart

@@ -0,0 +1,83 @@
+/// Tests for TranscriptPublisher — bridges a TranscriptReader onto the
+/// kernel MessageBus (T-137/D-75). Pure Dart: MessageBus + reader have no
+/// Flutter dependency, so this runs under `package:test`.
+library;
+
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:clide/builtin/claude/src/transcript_publisher.dart';
+import 'package:clide/builtin/claude/src/transcript_reader.dart';
+import 'package:clide/kernel/src/events/message_bus.dart';
+import 'package:test/test.dart';
+
+Map<String, dynamic> _userLine(String uuid, String text) => {
+      'type': 'user',
+      'uuid': uuid,
+      'parentUuid': '',
+      'isSidechain': false,
+      'version': '2.1.143',
+      'timestamp': '2026-05-16T08:53:06.708Z',
+      'message': {'role': 'user', 'content': text},
+    };
+
+Map<String, dynamic> _asstLine(String uuid, String text) => {
+      'type': 'assistant',
+      'uuid': uuid,
+      'parentUuid': '',
+      'isSidechain': false,
+      'version': '2.1.143',
+      'timestamp': '2026-05-16T08:53:07.708Z',
+      'message': {
+        'role': 'assistant',
+        'content': [
+          {'type': 'text', 'text': text}
+        ],
+      },
+    };
+
+void main() {
+  group('TranscriptPublisher', () {
+    late Directory base;
+    const workspace = '/pub/ws';
+
+    setUp(() async => base = await Directory.systemTemp.createTemp('transcript_publisher_test_'));
+    tearDown(() async => base.delete(recursive: true));
+
+    test('republishes reader items onto the bus (lead channel + item key)', () async {
+      final dir = Directory('${base.path}/${workspace.replaceAll('/', '-')}');
+      await dir.create(recursive: true);
+      File('${dir.path}/session-abc.jsonl').writeAsStringSync(
+        '${[_userLine('u1', 'hello'), _asstLine('a1', 'hi there')].map(jsonEncode).join('\n')}\n',
+      );
+
+      final bus = MessageBus();
+      addTearDown(bus.dispose);
+      final received = <Message>[];
+      // Subscribe before the publisher starts the reader's first poll.
+      final sub = bus.subscribe(publisher: ClaudeConversation.publisher, channel: ClaudeConversation.leadChannel).listen(received.add);
+
+      final reader = TranscriptReader(
+        workspace,
+        projectsBase: base.path,
+        pollInterval: const Duration(milliseconds: 20),
+      );
+      final pub = TranscriptPublisher(messages: bus, reader: reader);
+
+      await Future<void>.delayed(const Duration(milliseconds: 200));
+      await sub.cancel();
+      await pub.dispose();
+
+      expect(received, hasLength(2));
+      expect(received.every((m) => m.data[ClaudeConversation.itemKey] is ConversationItem), isTrue);
+      final items = received.map((m) => m.data[ClaudeConversation.itemKey]).toList();
+      expect(items.first, isA<UserMessage>());
+      expect((items.first as UserMessage).text, 'hello');
+      expect(items[1], isA<AssistantTextMessage>());
+    });
+
+    test('teammateChannel namespaces by agentId', () {
+      expect(ClaudeConversation.teammateChannel('coder@team-x'), 'conversation/coder@team-x');
+    });
+  });
+}