Accessible name is not defined for iframe in windows.

### GrapesJS version

- [x] I confirm to use the latest version of GrapesJS

### What browser are you using?

Edge (Version 143.0.3650.46), Chrome (Version 143.0.7499.41)

### Reproducible demo link

https://grapesjs.com/demo

### Describe the bug

**Test Environment:**
OS: Windows 11 version 25H2 (OS Build 26220.7271)
Browser: Edge (Version 143.0.3650.46), Chrome (Version 143.0.7499.41)
Screen Reader: NVDA (2025.3.1), JAWS (2025.2508.120)
URL: https://grapesjs.com/demo

**User Impact:**
Screen reader users cannot identify the purpose of the iframe because it lacks an accessible name. This makes navigation and understanding of embedded content difficult, reducing usability and compliance with WCAG guidelines.

**Repro Steps:**

1. Open the URL: https://grapesjs.com/demo in edge browser.
2. 'GrapeJS Demo' page will appear.
3. Press tab key to navigate on the page.
4. Verify whether Accessible names is defined for iframe or not.

**Actual Result:**
Accessible name is not defined for iframe in windows.

**Refer Attachment:**

1. Accessible name is not defined for iframe in windows.png
2. Accessible name is not defined for iframe in windows.mp4

https://github.com/user-attachments/assets/62a267dd-64e8-43bc-be7b-209b828a0cbe

**Expected Result:**
Accessible name should be defined for iframe in windows.

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct