fix(launcher): close Campaign LA LA1 review findings

src/AcDream.App/RuntimeOptions.cs

@@ -2,6 +2,8 @@ using System;
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
+using System.Reflection;
+using System.Text;
 using AcDream.App.Configuration;
 using AcDream.App.Rendering.Residency;
 using AcDream.App.Streaming;
@@ -266,6 +268,44 @@ public sealed record RuntimeOptions(
                 selector.Id,
                 selector.Name);
 
+    private static readonly PropertyInfo[] PrintableProperties =
+        typeof(RuntimeOptions)
+            .GetProperties(
+                BindingFlags.Instance
+                | BindingFlags.Public
+                | BindingFlags.DeclaredOnly)
+            .Where(static property =>
+                property.GetMethod is not null
+                && property.GetIndexParameters().Length == 0)
+            .OrderBy(static property => property.MetadataToken)
+            .ToArray();
+
+    /// <summary>
+    /// Campaign LA LA1 defense in depth: positional records normally print
+    /// every public property, including the live password. Preserve that
+    /// ordinary diagnostic property set while substituting the one sensitive
+    /// value before it can reach a log, debugger display, or exception.
+    /// Reflection is cached once and runs only on the diagnostic
+    /// <see cref="object.ToString"/> path.
+    /// </summary>
+    private bool PrintMembers(StringBuilder builder)
+    {
+        ArgumentNullException.ThrowIfNull(builder);
+        for (int index = 0; index < PrintableProperties.Length; index++)
+        {
+            PropertyInfo property = PrintableProperties[index];
+            if (index != 0)
+                builder.Append(", ");
+            builder.Append(property.Name);
+            builder.Append(" = ");
+            builder.Append(
+                property.Name == nameof(LivePass) && LivePass is not null
+                    ? "<redacted>"
+                    : property.GetValue(this));
+        }
+        return PrintableProperties.Length != 0;
+    }
+
     /// <summary>True iff live-mode credentials are present and valid for connecting.</summary>
     public bool HasLiveCredentials =>
         LiveMode && !string.IsNullOrEmpty(LiveUser) && !string.IsNullOrEmpty(LivePass);