Media browser: recursive scan entire content/ tree, /-media/ URL prefix, editor change detection fix

- handleMediaList() now scans content/ recursively for all media files
- URLs use /-media/ prefix mapping directly to content/ (no special cases)
- index.php: added /-media/ route, kept /-assets/ for backward compat
- editor-toolbar.js: fixed editor.on('change') placement (was inside switchMode)
- content-edit.php and content-new.php: back-btn unsaved-changes detection
- Removed unused __editorCleanup global

plugins/HTMLBlock/HTMLBlock.php

@@ -24,11 +24,6 @@ class HTMLBlock
         $currentLang = $this->api ? $this->api->getCurrentLanguage() : 'nl';
         
         $content = '
-            <div class="card mb-3">
-                <div class="card-header">
-                    <h5 class="mb-0">' . $this->config['title'] . '</h5>
-                </div>
-                <div class="card-body">
                     <p class="mb-2"><strong>Huidige pagina:</strong> ' . htmlspecialchars($currentPage) . '</p>
                     <p class="mb-2"><strong>Taal:</strong> ' . strtoupper($currentLang) . '</p>
                     <p class="mb-3"><strong>Homepage:</strong> ' . ($isHomepage ? 'Ja' : 'Nee') . '</p>';