Implement a minimal, dependency-free publishing tool to manage news
and articles. The app includes:
- A Markdown-based block editor with rich-text capabilities.
- Image upload and resizing using GD.
- Support for drafts, scheduled publishing, and a trash system.
- Integrated Basic Auth protection via PHP and .htpasswd.
- A global plugin for automatic execution of scheduled posts.
The tool reuses core site logic in custom/plugins/publiser-lib.php to
ensure consistency between the editor and the live site.
