Make the icon toggle scrim a plain element, not a hidden button

Problem/Motivation

The scrim that dims the page behind the open full-width search is a button with aria-hidden="true" and tabindex="-1", a control taken out of the accessibility tree. The Varbase functional testing suite flags it on 20 pages. Screen readers already skip it, so this is about the markup, not a visible bug.

Steps to reproduce

1. Install RightUp and open the homepage as anonymous.
2. Inspect .icon-toggle__scrim in the header search.

Proposed resolution

Render the scrim as a div with aria-hidden="true" and drop the button resets from the SCSS. icon-toggle.js binds by class, so it does not change: a click outside the panel and Escape still close it.

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

• None visible.

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• N/A

AI-Generated: Yes