Fix: add keyboard accessibility to popup close icons

[DhyaniKavya]

issue: #5878

Problem:-
-Popup close controls (e.g., print preview and error dialogs) are implemented as elements with onclick handlers. These elements are not focusable and cannot be activated via keyboard.
-Close icons are skipped when navigating with the Tab key
-Keyboard users cannot dismiss popup dialogs
-Assistive technologies do not recognize the icons as interactive controls
-This creates an accessibility barrier and does not meet WCAG 2.1 keyboard accessibility guidelines

Solution:-
-This PR adds keyboard accessibility support to the popup close icons while preserving existing behavior.
-adds role="button" for semantic meaning
-adds tabindex="0" to enable keyboard focus
-adds keyboard activation via Enter and Space
-preserves existing click functionality
-does not alter layout, styling, or popup logic

Changes Made:-
-File modified:
->index.html

added role="button" to popup close icons
added tabindex="0" to enable keyboard focus
added onkeydown handler for Enter/Space activation
ESLint: ✅ no lint errors
Tests: ⚠️ pre-existing failures on master (unrelated to this change)

Impact:-
-Enables keyboard users to dismiss popup dialogs
-Improves screen reader accessibility
-Enhances WCAG 2.1 compliance
-No functional regressions
-Minimal and safe change

Notes:-
This change is intentionally minimal and non-breaking. It improves accessibility without modifying popup logic, layout, or styling. The implementation follows standard accessibility best practices while preserving existing behavior.

Happy to refine further if maintainers prefer a different approach

[github-actions]

❌ Some Jest tests failed. Please check the logs and fix the issues before merging.

Failed Tests:

palette.test.js
logo.test.js
logoconstants.test.js

[DhyaniKavya]

@omsuneri please review this PR . Some tests are failing on the upstream master branch. @vyagh has already raised a PR for "test failing" fix , so after fix the tests will be passed as usual . Thankyou

[github-actions]

✅ All Jest tests passed! This PR is ready to merge.

[DhyaniKavya]

@omsuneri @walterbender Rebased the branch successfully and all tests are passing now . Please review the changes, if anything needs change, i am open to address it. Thankyou

[zealot-zew]

Screen.Recording.2026-03-01.at.2.12.37.PM.mov

i can highlight the message dialog using Enter but cannot close it?