feat:增加消息记录功能

lib/models/chat_session.g.dart

@@ -0,0 +1,30 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'chat_session.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+ChatSession _$ChatSessionFromJson(Map<String, dynamic> json) => ChatSession(
+  conversationId: (json['conversationId'] as num).toInt(),
+  targetUserId: (json['targetUserId'] as num).toInt(),
+  title: json['title'] as String,
+  avatarUrl: json['avatarUrl'] as String,
+  msgType: (json['msgType'] as num).toInt(),
+  lastMessageContent: json['lastMessageContent'] as String,
+  lastMessageTime: DateTime.parse(json['lastMessageTime'] as String),
+  unreadCount: (json['unreadCount'] as num).toInt(),
+);
+
+Map<String, dynamic> _$ChatSessionToJson(ChatSession instance) =>
+    <String, dynamic>{
+      'conversationId': instance.conversationId,
+      'targetUserId': instance.targetUserId,
+      'title': instance.title,
+      'avatarUrl': instance.avatarUrl,
+      'msgType': instance.msgType,
+      'lastMessageContent': instance.lastMessageContent,
+      'lastMessageTime': instance.lastMessageTime.toIso8601String(),
+      'unreadCount': instance.unreadCount,
+    };