feat:增加消息记录功能

lib/apis/message_api.dart

@@ -0,0 +1,19 @@
+import 'package:sweet_chat_app/models/chat_message.dart';
+import 'package:sweet_chat_app/models/chat_session.dart';
+import 'package:sweet_chat_app/services/dio_service.dart';
+
+Future<List<ChatSession>> getChatSessionApi(int userId) async {
+  final res = await dioService.get('/message/session/$userId');
+
+  if (res.data == null) return [];
+
+  return (res.data as List).map((e) => ChatSession.fromJson(e)).toList();
+}
+
+Future<List<ChatMessage>> getChatMessageApi(int conversationId) async {
+  final res = await dioService.get('/message/session/$conversationId/detail');
+
+  if (res.data == null) return [];
+
+  return (res.data as List).map((e) => ChatMessage.fromJson(e)).toList();
+}