feat: add standard file headers to all 57 files missing them

- Add Copyright + FILE INFORMATION headers to 11 PHP enterprise classes
- Add FILE INFORMATION blocks to 9 PHP files with incomplete headers
- Add headers to 2 test files
- Add markdown comment headers to 27 index/README files
- Add headers to 5 root markdown files
- Add FILE INFORMATION to 4 files with existing but incomplete headers

All files now conform to moko-platform file header standard.

Authored-by: Moko Consulting

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lib/Enterprise/ProjectPluginInterface.php

@@ -2,6 +2,20 @@
 
 declare(strict_types=1);
 
+/* Copyright (C) 2026 Moko Consulting <hello@mokoconsulting.tech>
+ *
+ * This file is part of a Moko Consulting project.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * FILE INFORMATION
+ * DEFGROUP: MokoStandards.Enterprise.Plugins
+ * INGROUP: MokoStandards.Enterprise
+ * REPO: https://git.mokoconsulting.tech/MokoConsulting/moko-platform
+ * PATH: /lib/Enterprise/ProjectPluginInterface.php
+ * BRIEF: Interface for project type plugins
+ */
+
 namespace MokoEnterprise;
 
 /**