fix(docx-io): keep every nested inline formatting tag on DOCX export

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Author: vincent69001

.changeset/docx-io-nested-inline-formatting.md

@@ -0,0 +1,5 @@
+---
+"@platejs/docx-io": patch
+---
+
+Fix DOCX export losing marks on text that carries several marks (for example bold and italic) and leaking a mark onto the text that follows it

apps/www/src/__tests__/package-integration/docx-io.roundtrip.slow.tsx

@@ -105,4 +105,20 @@ describe('docx roundtrip', () => {
 
     expect(roundtrippedNodes.length).toBeGreaterThan(0);
   });
+
+  it('keeps every mark of a leaf that carries several marks', async () => {
+    const editor = createTestEditor();
+    const nodes: TNode[] = [
+      {
+        children: [{ bold: true, italic: true, text: 'bold italic' }],
+        type: 'p',
+      },
+    ];
+    const roundtrippedNodes = await importDocxBuffer(
+      editor,
+      await exportNodesToDocx(nodes)
+    );
+
+    expect(roundtrippedNodes).toEqual(nodes);
+  });
 });