feat: 应用名称更新为灵可析并增强 Chat 功能

- 更新 Android/iOS 应用名称和图标为灵可析
- Chat 支持取消正在运行的 Agent 对话
- 改进 ChatBloc 状态管理（区分发送/等待/流式/取消状态）
- HomeScreen 支持外部注入 ChatBloc 和显示等待指示器
- 后端 Agent 运行服务优化（消息处理、usage 追踪）
- 补充相关单元测试和 Widget 测试

apps/lib/features/chat/data/services/ag_ui_service.dart

@@ -25,6 +25,7 @@ class AgUiService {
   final MockHistoryService _historyService;
   final Map<String, List<String>> _mockSseLinesByThread = {};
   final Map<String, String> _lastEventIdByThread = {};
+  int _activeStreamToken = 0;
 
   String? _threadId;
   bool _hasMoreHistory = false;
@@ -41,6 +42,7 @@ class AgUiService {
   }
 
   Future<void> sendMessage(String content) async {
+    final streamToken = ++_activeStreamToken;
     final runInput = _buildRunInput(content: content);
     final response = await _apiClient.post<Map<String, dynamic>>(
       '/api/v1/agent/runs',
@@ -55,7 +57,7 @@ class AgUiService {
       throw StateError('Missing threadId in /agent/runs response');
     }
     _threadId = threadId;
-    await _streamEventsFromApi(threadId);
+    await _streamEventsFromApi(threadId, streamToken: streamToken);
   }
 
   Future<void> loadHistory({DateTime? beforeDate}) async {
@@ -105,6 +107,7 @@ class AgUiService {
     required String toolName,
     required Map<String, dynamic> args,
   }) async {
+    final streamToken = ++_activeStreamToken;
     final threadId = _threadId;
     if (threadId == null || threadId.isEmpty) {
       throw StateError('Missing threadId for resume');
@@ -150,7 +153,7 @@ class AgUiService {
         _threadId = responseThreadId;
       }
     }
-    await _streamEventsFromApi(threadId);
+    await _streamEventsFromApi(threadId, streamToken: streamToken);
   }
 
   bool hasEarlierHistory(DateTime fromDate) {
@@ -160,7 +163,14 @@ class AgUiService {
     return _hasMoreHistory;
   }
 
-  Future<void> _streamEventsFromApi(String threadId) async {
+  Future<void> cancelCurrentRun() async {
+    _activeStreamToken += 1;
+  }
+
+  Future<void> _streamEventsFromApi(
+    String threadId, {
+    required int streamToken,
+  }) async {
     final lastEventId = _lastEventIdByThread[threadId];
     final headers = <String, String>{'Accept': 'text/event-stream'};
     if (lastEventId != null && lastEventId.isNotEmpty) {
@@ -175,6 +185,9 @@ class AgUiService {
     String? eventId;
     final dataBuffer = StringBuffer();
     await for (final line in sseLines) {
+      if (streamToken != _activeStreamToken) {
+        break;
+      }
       if (line.isEmpty) {
         if (dataBuffer.isNotEmpty) {
           final raw = dataBuffer.toString();