🐛 Fix text-align before typing and sync attrs with v2 editor

frontend/text-editor/src/editor/controllers/SelectionController.js

@@ -2030,6 +2030,18 @@ export class SelectionController extends EventTarget {
 
         this.#textNodeIterator.nextNode();
       } while (this.#textNodeIterator.currentNode);
+    } else {
+      // Empty paragraph uses a text span with <br> only (no text node). The
+      // selection is then on the line-break element, not a TEXT_NODE, so none
+      // of the branches above run — only setRootStyles applied. Paragraph
+      // styles (e.g. text-align) must still be applied before the user types.
+      const paragraph = this.startParagraph;
+      if (paragraph) {
+        setParagraphStyles(paragraph, newStyles);
+        for (const textSpan of paragraph.children) {
+          setTextSpanStyles(textSpan, newStyles);
+        }
+      }
     }
     return this.#notifyStyleChange();
   }

frontend/text-editor/src/editor/controllers/SelectionController.test.js

@@ -1626,6 +1626,23 @@ describe("SelectionController", () => {
     );
   });
 
+  test("`applyStyles` sets paragraph styles when selection is on <br> (empty paragraph)", () => {
+    const textEditorMock = TextEditorMock.createTextEditorMockWithText("");
+    const root = textEditorMock.root;
+    const selection = document.getSelection();
+    const selectionController = new SelectionController(
+      textEditorMock,
+      selection,
+    );
+    const lineBreak = root.firstChild.firstChild.firstChild;
+    expect(lineBreak.nodeName).toBe("BR");
+    focus(selection, textEditorMock, lineBreak, 0, lineBreak, 0);
+    selectionController.applyStyles({
+      "text-align": "center",
+    });
+    expect(root.firstChild.style.textAlign).toBe("center");
+  });
+
   test("`selectAll` should select everything", () => {
     const textEditorMock = TextEditorMock.createTextEditorMockWithParagraphs([
       createParagraphWith(["Hello, "], {