refactor(apps): 重构数据层目录结构并新增启动预热编排器

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

@@ -5,9 +5,10 @@ import 'dart:typed_data';
 
 import 'package:dio/dio.dart';
 import 'package:image_picker/image_picker.dart';
-import 'package:social_app/core/network/i_api_client.dart';
+import 'package:social_app/data/network/i_api_client.dart';
 
 import '../models/ag_ui_event.dart';
+import '../repositories/chat_history_repository.dart';
 
 typedef EventCallback = void Function(AgUiEvent event);
 
@@ -43,6 +44,7 @@ class _RunInputPayload {
 
 class AgUiService {
   final IApiClient _apiClient;
+  final ChatHistoryRepository? _historyRepository;
   EventCallback onEvent;
   final Map<String, String> _lastEventIdByThread = {};
   int _activeStreamToken = 0;
@@ -54,9 +56,13 @@ class AgUiService {
   String? _activeRunId;
   bool _hasMoreHistory = false;
 
-  AgUiService({EventCallback? onEvent, required IApiClient apiClient})
-    : onEvent = onEvent ?? ((_) {}),
-      _apiClient = apiClient;
+  AgUiService({
+    EventCallback? onEvent,
+    required IApiClient apiClient,
+    ChatHistoryRepository? historyRepository,
+  }) : onEvent = onEvent ?? ((_) {}),
+       _apiClient = apiClient,
+       _historyRepository = historyRepository;
 
   Future<SendMessageResult> sendMessage(
     String content, {
@@ -105,18 +111,28 @@ class AgUiService {
   }
 
   Future<HistorySnapshot> loadHistory({DateTime? beforeDate}) async {
+    final repository = _historyRepository;
+    final snapshot = repository != null
+        ? await repository.loadHistory(
+            threadId: _threadId,
+            beforeDate: beforeDate,
+          )
+        : await _loadHistoryFromApi(beforeDate: beforeDate);
+    if (snapshot.threadId != null && snapshot.threadId!.isNotEmpty) {
+      _threadId = snapshot.threadId;
+    }
+    _hasMoreHistory = snapshot.hasMore;
+    return snapshot;
+  }
+
+  Future<HistorySnapshot> _loadHistoryFromApi({DateTime? beforeDate}) async {
     final path = _buildHistoryPath(beforeDate: beforeDate);
     final response = await _apiClient.get<Map<String, dynamic>>(path);
     final payload = response.data;
     if (payload is! Map<String, dynamic>) {
       throw StateError('Invalid /agent/history response');
     }
-    final snapshot = HistorySnapshot.fromJson(payload);
-    if (snapshot.threadId != null && snapshot.threadId!.isNotEmpty) {
-      _threadId = snapshot.threadId;
-    }
-    _hasMoreHistory = snapshot.hasMore;
-    return snapshot;
+    return HistorySnapshot.fromJson(payload);
   }
 
   Future<Uint8List> fetchAttachmentPreview(String previewPath) async {