Allow parent to add comments on submitted documents

Switch admin doc viewer from view mode to comment-only mode so the
parent can annotate student work without editing the text.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/admin.js

@@ -3346,9 +3346,11 @@ async function openAdminDocViewer(id, key, filename, title) {
     frame.innerHTML = `<div class="docs-error">Could not load document config.</div>`;
     return;
   }
-  // Parent views in read mode
+  // Parent can comment but not edit the student's text
   config.editorConfig = config.editorConfig || {};
-  config.editorConfig.mode = 'view';
+  config.editorConfig.mode = 'edit';
+  config.document = config.document || {};
+  config.document.permissions = { edit: false, comment: true, download: true, print: true };
 
   function initEditor() {
     adminDocsEditorInstance = new window.DocsAPI.DocEditor('admin-doc-frame', config);