Initial commit: BARON SSO 샘플 (WebView OIDC PKCE 인증 라이브러리 + 데모 앱)

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

BaronSoftware.SSO/Exceptions/UserJsonParsingException.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace BaronSoftware.SSO
+{
+    public class UserJsonParsingException : Exception
+    {
+        public string Raw { get; init; }
+
+    }
+}