Default keyboard: Focus indicator not visible on "Delete Profile" button in My Profile dialog (User menu)

Describe the bug
When navigating using the default keyboard (Tab/Enter), the focus indicator (focus outline/border) is not visible when focus moves to the "Delete Profile" button within the My Profile dialog opened from the User menu.

Steps to reproduce the behavior:

1. Navigate to https://makecode.microbit.org/beta.
2. Sign in with a valid Microsoft account.
3. Press Tab repeatedly until focus is on the User menu button.
4. Press Enter twice to open the My Profile dialog.
5. Continue pressing Tab until focus reaches the "Delete Profile" button.
6. Observe the focus indicator on the button.

Actual behavior
The "Delete Profile" button receives focus, but no visible focus indicator (outline/border) is displayed.

Expected behavior
A clearly visible focus indicator should be displayed when the "Delete Profile" button is focused, ensuring accessibility compliance and proper keyboard navigation feedback.

Screen Recording
https://github.com/user-attachments/assets/9f85831c-feee-40be-8c2c-83600da36528

Additional context
1.OS: Windows 11 25H2 & Mac Mini M2 macOS Tahoe 26.5
2.Browser: Chrome, Edge, Firefox, and Safari
3.makecode.microbit.org version: 8.1.17
4.Microsoft MakeCode version: 12.3.12

Start by reproducing the issue in the My Profile dialog opened from the User menu, then locate the dialog and Delete Profile button implementation. Verify keyboard focus behavior in a supported browser and confirm that the focused button has a clearly visible indicator without changing other dialog interactions.