사용자 검증기 구조 분리: 내부(Family) / 외부(Extra) 검증 구분

- IUserValidator.Validate: bool 반환 → void (인증 실패 시 예외로 처리)
- BaronSSOOption: Validator → ExtraUserValidator로 명명, FamilyValidator(기본 DefaultFamilyUserValidator) 추가
- DefaultFamilyUserValidator 신규: Center/Family 테넌트 사용자 통과, 그 외 InvalidUserException
- BaronSSO.SignInAsync: Family/Extra 검증기 적용 흐름 정리
- InvalidUserException: UserInfo 기반 생성자
- Sample(MainWindow/SampleSettings/SimpleUserValidator) 갱신

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

BaronSoftware.SSO/BaronSSO.cs

@@ -1,5 +1,3 @@
-using BaronSoftware.SSO.Exceptions;
-
 namespace BaronSoftware.SSO
 {
     /// <summary>
@@ -36,37 +34,45 @@ namespace BaronSoftware.SSO
         }
 
         /// <summary>웹뷰 로그인 창을 띄워 인증합니다.</summary>
-        public async Task SignInAsync() => await SignInAsync(null);
+        public async Task SignInAsync()
+        {
+            UserInfo? user = null;
+            if (option.EnableAutoLogin)
+                user = UserInfo.FromSsoFile();
+
+            await SignInAsync(user?.RefreshToken);
+        }
 
-        /// <summary>웹뷰 로그인 창을 띄워 인증합니다.</summary>
         public async Task SignInAsync(string refreshToken)
         {
             UserInfo user = null;
-            if(option.EnableAutoLogin)
-                user = UserInfo.FromSsoFile();
-
             var isConnected = await CheckConnection();
-            if(!isConnected && option.EnableOffline)
+            if (isConnected)
             {
+                var token = await client.LoginAsync(refreshToken);
+                var userJson = await client.GetUserInfoAsync(token.AccessToken);
+                if (string.IsNullOrEmpty(userJson))
+                    throw new InvalidOperationException($"Failed to get userinfo : {token.ToString()}");
+
+                user = UserInfo.FromJson(userJson, token);
                 if (user == null)
-                    throw new InvalidUserException("Not found authorized last user.");
-                option?.Validator?.Validate(user);
-                return;
+                    throw new InvalidUserException($"Broken user token. Token {token.ToString()}, UserJson {userJson}");
+            }
+            else
+            {
+                if (!option.EnableOffline)
+                    throw new InvalidOperationException("Network isn't available.");
+
+                user = UserInfo.FromSsoFile();
+                if (user == null)
+                    throw new InvalidUserException("Not found sso data for offline.");
             }
 
-            var token = await client.LoginAsync(refreshToken);
-            var userJson = await client.GetUserInfoAsync(token.AccessToken);
-            if (string.IsNullOrEmpty(userJson))
-                throw new InvalidOperationException($"Failed to get userinfo : {token.ToString()}");
-
-            user = UserInfo.FromJson(userJson, token);
-
-            if (user == null || option?.Validator == null)
-                throw new NullReferenceException("user or validator option is null");
-
             // 가족사가 아니고, 인증도 실패 시
-            if(!user.IsFamily()&& !option.Validator.Validate(user))
-                throw new InvalidUserException("Failed to authorize user");
+            if (user.IsFamily())
+                option?.FamilyValidator?.Validate(user);
+            else
+                option?.ExtraUserValidator?.Validate(user);
 
             CurrentUser = user;
             CurrentUser.Save();