Verify actual current-token access to built-in event channels (#432)

* Add actual current-token native channel read evidence

* Use supported workflow shells and link channel-read changelogs

* Handle real event exceptions and bind loaded token helper to source

* Capture query-token interval after evidence and metadata preparation

* Retain native child process exit evidence across PowerShell engines

* Bound native reader fixture pipe draining and child termination

* Preserve native errors from attributed channel query statuses

scripts/ChannelReadNative.cs

@@ -0,0 +1,28 @@
+using System;
+using System.ComponentModel;
+using System.Runtime.InteropServices;
+namespace Wela.ChannelRead {
+    public static class Token {
+        public static string SourceSha256;
+        [StructLayout(LayoutKind.Sequential)] public struct Luid {
+            public UInt32 Low; public Int32 High;
+            public override string ToString() { return ((UInt32)High).ToString("x8") + Low.ToString("x8"); }
+        }
+        [StructLayout(LayoutKind.Sequential)] public struct Statistics {
+            public Luid TokenId, AuthenticationId;
+            public Int64 ExpirationTime;
+            public Int32 TokenType, ImpersonationLevel;
+            public UInt32 DynamicCharged, DynamicAvailable, GroupCount, PrivilegeCount;
+            public Luid ModifiedId;
+        }
+        [DllImport("advapi32.dll", SetLastError=true)]
+        private static extern bool GetTokenInformation(IntPtr token, int informationClass, out Statistics information, int size, out int returned);
+        public static Statistics Read(IntPtr token) {
+            Statistics value; int returned;
+            int size = Marshal.SizeOf(typeof(Statistics));
+            if (!GetTokenInformation(token, 10, out value, size, out returned)) throw new Win32Exception(Marshal.GetLastWin32Error());
+            if (returned != size || value.TokenType != 1) throw new InvalidOperationException("Expected complete primary-token statistics.");
+            return value;
+        }
+    }
+}