fix: unified undo/redo - toolbar+keyboard use same stack, works with typing+formatting+Quran apply

src/index.html

@@ -1347,6 +1347,7 @@
     function _replaceInEditor(newText, ref) {
       var editor = document.getElementById('editor-container');
       if (!editor || !_quranCurrentQuery) return false;
+      pushUndoState(); // Save state before Quran replace
       closeQuranModal();
       // Replace in editor: wrap in quran-applied span to protect from analysis
       var plain = editor.textContent || '';

src/js/editor.js

@@ -79,6 +79,8 @@ function initEditor() {
     }
   } catch (e) {}
 
+  // Debounced undo push — saves state after 500ms of no typing
+  let _undoInputTimer = null;
   editor.addEventListener('input', () => {
     // Pipeline Hardening v3.3: Skip re-analysis when programmatically applying suggestions
     if (_isApplyingSuggestion) return;
@@ -86,6 +88,9 @@ function initEditor() {
     updateEditorStats();
     updatePlaceholder();
     analyzeTextDelayed();
+    // Push undo state after typing pauses
+    clearTimeout(_undoInputTimer);
+    _undoInputTimer = setTimeout(pushUndoState, 500);
     try {
       localStorage.setItem('bayan_editor_draft', editor.innerHTML);
     } catch (e) {}

src/js/format.js

@@ -8,6 +8,7 @@
  * @param {boolean} [keepSelection] - if true, don't collapse selection
  */
 function execFormat(command, value, keepSelection) {
+  pushUndoState(); // Save state before formatting
   document.execCommand(command, false, value !== undefined ? value : null);
   const editor = getEditorElement();
   if (editor) editor.focus();
@@ -29,9 +30,9 @@ function formatItalic() { execFormat('italic'); }
 function formatUnderline() { execFormat('underline'); }
 function formatStrikethrough() { execFormat('strikethrough'); }
 
-/* ── Undo / Redo (handles both typing and formatting) ── */
-function formatUndo() { execFormat('undo', undefined, true); }
-function formatRedo() { execFormat('redo', undefined, true); }
+/* ── Undo / Redo (uses custom stack — same as Ctrl+Z/Y) ── */
+function formatUndo() { editorUndo(); }
+function formatRedo() { editorRedo(); }
 
 /* ── Alignment (applies to paragraph containing selection/cursor) ── */
 function formatAlignRight() { execFormat('justifyRight'); }