feat(apps): 重构 UI 架构为 presentation 层并新增 l10n 国际化支持

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

@@ -5,7 +5,7 @@ import 'dart:typed_data';
 
 import 'package:dio/dio.dart';
 import 'package:image_picker/image_picker.dart';
-import 'package:social_app/core/api/i_api_client.dart';
+import 'package:social_app/core/network/i_api_client.dart';
 
 import '../models/ag_ui_event.dart';
 
@@ -155,8 +155,8 @@ class AgUiService {
   }
 
   bool hasEarlierHistory(DateTime fromDate) {
-    // 历史是否还有更多由后端 history snapshot 的 hasMore 驱动。
-    // 参数保留是为了兼容 ChatBloc 现有调用签名。
+    // Whether earlier history exists is driven by backend snapshot.hasMore.
+    // Keep the parameter for compatibility with the current ChatBloc signature.
     final _ = fromDate;
     return _hasMoreHistory;
   }