Keep the focus ring on the selected Upload or Generate option

Problem/Motivation

In css/ai-media.admin.css the [aria-current="true"] rule sets box-shadow after the :focus-visible rule with the same specificity. Under Default Admin, keyboard focus on the selected option is invisible. Gin is not affected.

Steps to reproduce

1. Use Default Admin.
2. Open a media add form with the Upload or Generate switch.
3. Tab to the selected option.

Proposed resolution

Add a combined [aria-current="true"]:focus-visible rule carrying both the bar and the ring.

Remaining tasks

• ✅ File an issue
• ❌ Addition/Change/Update/Fix
• ❌ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ➖ Developer Documentation support
• ➖ User Guide Documentation support
• ➖ UX/UI designer responsibilities
• ➖ Accessibility and Readability
• ❌ Reviewed by a human
• ❌ Code review by maintainers
• ❌ Full testing and approval
• ❌ Credit contributors
• ❌ Review with the product owner
• ✅ Update Release Notes
• ✅ Release

User interface changes

• Before (1.0.x): the focused, selected option shows no focus ring (Default Admin).
  
• After: the selected bar and the focus ring show together.
  

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• N/A

AI-Generated: Yes