AI助手优化-头像和对话功能

lib/models/auth_response.dart

@@ -3,12 +3,21 @@ class AuthResponse {
   final String? username;
   final String? nickname;
 
-  const AuthResponse({required this.token, this.username, this.nickname});
+  /// 头像相对路径。null = 用默认头像
+  final String? avatar;
+
+  const AuthResponse({
+    required this.token,
+    this.username,
+    this.nickname,
+    this.avatar,
+  });
 
   factory AuthResponse.fromJson(Map<String, dynamic> json) => AuthResponse(
         token: json['token']?.toString() ?? '',
         username: json['username']?.toString(),
         nickname: json['nickname']?.toString(),
+        avatar: json['avatar']?.toString(),
       );
 }
 
@@ -17,13 +26,27 @@ class UserInfo {
   final String username;
   final String nickname;
 
-  const UserInfo({this.id, required this.username, required this.nickname});
+  /// 头像相对路径。null = 用默认头像
+  final String? avatar;
 
-  Map<String, dynamic> toJson() => {'id': id, 'username': username, 'nickname': nickname};
+  const UserInfo({
+    this.id,
+    required this.username,
+    required this.nickname,
+    this.avatar,
+  });
+
+  Map<String, dynamic> toJson() => {
+        'id': id,
+        'username': username,
+        'nickname': nickname,
+        'avatar': avatar,
+      };
 
   factory UserInfo.fromJson(Map<String, dynamic> json) => UserInfo(
         id: json['id']?.toString(),
         username: json['username']?.toString() ?? '',
         nickname: json['nickname']?.toString() ?? '',
+        avatar: json['avatar']?.toString(),
       );
 }