Normalize Comment Terminology

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

Util/OS/FolderDialogUtil.cs

@@ -22,7 +22,7 @@ namespace ADOFAIRenderer.Util.OS;
 ///   cancelled or failed), <c>kdialog --getexistingdirectory</c>.
 /// </para>
 /// <para>
-/// The dialog runs off the Unity main thread so the game keeps rendering frames while it is open. Only one dialog can be open
+/// The dialog runs off the main Unity thread so the game keeps rendering frames while it is open. Only one dialog can be open
 /// at a time. Failures are reported to the callback as null (same as cancel); exceptions are logged as warnings, except a
 /// zenity start failure, which silently moves on to kdialog.
 /// </para>
@@ -43,7 +43,7 @@ internal static class FolderDialogUtil
     /// "FolderDialog-Win"; macOS/Linux: thread pool task) and <paramref name="onSelected"/> receives the result.
     /// </para>
     /// <para>
-    /// Callback thread: when the caller has a <see cref="SynchronizationContext"/> (the Unity main thread has one), the callback
+    /// Callback thread: when the caller has a <see cref="SynchronizationContext"/> (the main Unity thread has one), the callback
     /// is posted to it and runs on the caller's thread; otherwise it runs on the dialog thread. Exceptions thrown by the
     /// callback are caught and logged.
     /// </para>