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/content-beheerder/paginas-beheren.md

@@ -5,12 +5,44 @@
 1. Login at `/admin`
 2. Go to **Content**
 3. Choose a folder or create a new page
-4. Edit content in the editor
+4. Edit content in the CodeMirror editor
 5. Save with Ctrl+S
 
 ## Editor features
 
-- **CodeMirror** editor with syntax highlighting
+- **CodeMirror** editor with syntax highlighting (Markdown, PHP, HTML)
 - **Toolbar** for quick Markdown insertion
-- **Live preview** via button
-- **Auto-save** backups in `.bak/` folder
+- **Shortcuts**: Ctrl+S (save), Ctrl+N (new)
+- **Auto-save** backups in `.bak/` folder
+
+## Layout selection
+
+On the content-edit page you can choose the layout from the layouts defined in `theme.json` (template mapping). The selected layout is stored in the frontmatter `layout:` key.
+
+```markdown
+---
+layout: left_sidebar
+---
+```
+
+Unknown layouts fall back to `config.default_template` from `theme.json`.
+
+## Plugin selection and order
+
+On the content-edit page you can choose content plugins for the sidebar:
+
+- **Selection** — Only content plugins (from `plugin.json` with `type: "content"`) appear in the plugin selection
+- **Order** — Adjust the order with up/down buttons
+- **Frontmatter update** — The frontmatter `plugins:` key is updated live on changes
+- **Layout without sidebar** — Plugins are hidden when the chosen layout has no sidebar (e.g. `full_content`)
+
+```markdown
+---
+layout: left_sidebar
+plugins:
+  - HTMLBlock
+  - Navigation
+---
+```
+
+The order in the frontmatter determines the order of the plugins in the sidebar (top to bottom).