Update all guides (NL + EN) for CodePress 2.5.2 features

- Admin guide: RBAC roles, role-based dashboard, plugin types (content/system)
- CodePress developer guide: plugin types, admin plugin API, SCSS compilation, asset serving
- Theme developer guide: SCSS sole CSS source, css_compiled read-only, guide layout
- Content manager guide: layout selection from theme.json, plugin order in frontmatter
- Both NL and EN updated with identical structure
- 35 files updated

guide/en/codepress-developer/routing.md

@@ -2,18 +2,60 @@
 
 ## Frontend routing
 
-Via `cms/router.php` for PHP dev server:
+Frontend routing goes through `cms/router.php` (PHP dev server) or `.htaccess` (Apache). Both provide clean URLs.
 
-```php
-// Clean URLs: /nl/page
-// Query: ?page=page&lang=nl
+### PHP dev server
+
+Start the server with:
+
+```bash
+php -S localhost:8080 cms/router.php
 ```
 
+`cms/router.php` serves:
+- Clean URLs: `/nl/page` → `public/index.php?page=page&lang=nl`
+- `themes/` assets
+- `admin/assets/` assets
+- `plugins/` assets
+
+### Apache (live server)
+
+`public/.htaccess` rewrites URLs to `public/index.php`. Asset URLs (`/themes/`, `/admin/assets/`, `/plugins/`) are forwarded to `public/asset.php`.
+
+`public/asset.php` serves files from the correct folders with the correct MIME type:
+- `/themes/<name>/assets/...` → `themes/<name>/assets/...`
+- `/admin/assets/...` → `admin/theme/default/assets/...`
+- `/plugins/<name>/assets/...` → `plugins/<name>/assets/...`
+
 ## Admin routing
 
-Via `public/admin.php`:
+Admin routing goes through `public/admin.php` with clean URLs:
+
+```
+/admin/dashboard   → ?route=dashboard
+/admin/content     → ?route=content
+/admin/plugins     → ?route=plugins
+```
+
+`cms/router.php` or `.htaccess` converts `/admin/<route>` to `?route=<route>`.
+
+### Route access control (RBAC)
+
+Each route is checked via `AdminAuth::hasPermission($route)`:
+- The `admin` role has wildcard `*` access
+- Other roles have an explicit list of allowed routes in `ROLE_PERMISSIONS`
+- Unauthorized routes return a **403 error**
+
+## Plugin admin routing
+
+System plugins can register admin routes. These are handled by `PluginManager::handleAdminRoute($route)`:
+
+1. The system plugin registers routes via `getAdminRoutes()`
+2. `PluginManager::getAdminMenuItems()` collects admin menu items via `getAdminMenu()`
+3. On an admin request `PluginManager::handleAdminRoute($route)` finds a plugin that handles the route
+4. The plugin method `handleAdminRoute($route)` renders the page content
 
 ```php
-// Routes: /admin/dashboard, /admin/content, etc.
-// Query parameter: ?route=dashboard
+// PluginManager calls this for /admin/my-system
+$plugin->handleAdminRoute('my-system');
 ```