CMS 2.0 - Theme engine, logging, admin improvements

Major changes:
- New ThemeManager with Twig templating and SCSS compilation
- Dynamic themes system (themes/default, themes/demo)
- LogManager with SQLite storage and syslog forwarding
- RequestLogger with static helper methods
- Admin UI overhaul (Bootstrap 5, dark mode)
- Admin config page with logging and theme settings
- Admin logs page with filters and search
- Removed legacy Mustache templates
- Removed test plugin and theme
- Composer dependencies: Twig, scssphp, CommonMark, MaxMind GeoIP

README.en.md

@@ -49,13 +49,20 @@ codepress/
 │   │   ├── config.php              # Configuration loader
 │   │   └── index.php               # Bootstrap (autoloader)
 │   ├── lang/                       # Language files (nl.php, en.php)
-│   ├── templates/                  # Mustache templates
-│   │   ├── layout.mustache
-│   │   ├── assets/ (header, navigation, footer)
-│   │   ├── markdown_content.mustache
-│   │   ├── php_content.mustache
-│   │   └── html_content.mustache
-│   └── router.php                  # PHP dev server router
+│   └── router.php                  # PHP dev server router (also serves /themes/)
+├── themes/                         # Dynamic themes (fully self-contained)
+│   ├── default/                    # Default theme
+│   │   ├── theme.json              # { title, default_layout, layout→.twig mapping, colors }
+│   │   ├── base.twig               # Main layout
+│   │   ├── full_content.twig       # Layout: full width
+│   │   ├── left_sidebar.twig       # Layout: sidebar left
+│   │   ├── right_sidebar.twig      # Layout: sidebar right
+│   │   ├── custom1.twig            # Layout: custom
+│   │   ├── partials/               # header, navigation, footer
+│   │   ├── css/theme.scss          # SCSS source (compiled at runtime)
+│   │   └── js/theme.js             # Theme JavaScript
+│   ├── demo/                       # Demo theme
+│   └── test/                        # Test theme
 ├── admin/                          # Admin panel
 │   ├── config/
 │   │   ├── app.php                # Admin configuration
@@ -96,7 +103,6 @@ codepress/
 {
     "site_title": "CodePress",
     "content_dir": "content",
-    "templates_dir": "cms/templates",
     "default_page": "index",
     "active_theme": "default",
     "language": {