Role is not defined for the 'Customer Onboarding Widget' floating icon button in windows.

### 📜 Issue Labels

- [x] Please familiarize yourself with the issue labels used in this project: [LABELS.md](https://github.com/backstage/backstage/blob/master/LABELS.md)

### 🔎 Search Terms

```plain
Role, Customer Onboarding Widget, floating icon button
```

### 🗃️ Project Area

Unknown

### 🔗 External Integration

N/A

### 📝 Description & Context

Role is not defined for the 'Customer Onboarding Widget' floating icon button in windows. Screen reader announces: Customer Onboarding widget region widget closed

https://github.com/user-attachments/assets/2fbaa3b9-b093-4253-816f-02239b0c0f4b

### 👍 Expected Behavior

Role as button should be defined for the 'Customer Onboarding Widget' floating icon button in windows.
Screen reader should announce as: Customer onboarding widget chat button collapsed

### 📦 Reproduction Repo

https://bakstage.ai/?utm_source=chatgpt.com#features

### 🥾 Reproduction steps

1. Open the URL: https://bakstage.ai/?utm_source=chatgpt.com#features in edge/chrome browsers.
2. Press tab key to reach to the 'Customer Onboarding Widget' floating icon button.
3. Verify whether role is defined for the 'Customer Onboarding Widget' floating icon button in windows or not.

### Have you read the Code of Conduct?

- [x] I have read the [Code of Conduct](https://github.com/backstage/backstage/blob/master/CODE_OF_CONDUCT.md)

### Are you willing to submit PR?

Undecided

No repository file or test is named. Reproduce the issue at the provided URL in Edge or Chrome, tab to the Customer Onboarding Widget floating icon button, and inspect its accessibility announcement. Done means the control has button semantics and a screen reader announces “Customer onboarding widget chat button collapsed.”

Written by the indexing model from the issue text.