Assembler: Pages - Improve tab navigation on Homepage and overall accessibility with a screen reader

[miksansegundo]

Related to #83501

Proposed Changes

• Make Homepage item focusable but dimmed (read only)
• Use checkbox role with aria-checked to let users know the items are checkable and their checked status

BEFORE	AFTER
Screen.Recording.2566-10-26.at.21.17.51.mov	Screen.Recording.2566-10-26.at.21.14.43.mov

References:

• https://reakit.io/docs/composite/#compositeitem
• https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Roles/checkbox_role
• https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Roles/listbox_role

Notes:

• Composite component is being migrated from reakit to ariakit
• The component CheckboxControl from @wordpress/components has a good accessibility but the solution in this PR works well too.
• I couldn't resist working on this because I like accessibility challenges and I missed testing it earlier. cc: @taipeicoder

Testing Instructions

• Access the assembler with the param &flags=pattern-assembler/add-pages
• Continue until "Add more pages" screen
• Navigate using the keyboard to verify the Homepage is focusable
  • You have to use the tab to get into the list and then use the arrow keys up/down
• Enable a screen reader (like Voice Over in Mac) and select pages using the spacebar or as Voice Over suggests use Control+Option+Spacebar

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• https://wpcalypso.wordpress.com/devdocs/docs/testing/index.md for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the "[Status] String Freeze" label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
• For changes affecting Jetpack: Have we added the "[Status] Needs Privacy Updates" label if this pull request changes what data or activity we track or use (p4TIVU-ajp-p2)?

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:commit-96547acf7b0519a800c681e13ea560b26ea70b28

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:commit-96547acf7b0519a800c681e13ea560b26ea70b28&env=jetpack

[matticbot]

Here is how your PR affects size of JS and CSS bundles shipped to the user's browser:

Sections (~44 bytes added 📈 [gzipped])

name         parsed_size           gzip_size
import-flow       +143 B  (+0.0%)      +44 B  (+0.0%)

Sections contain code specific for a given set of routes. Is downloaded and parsed only when a particular route is navigated to.

Legend

What is parsed and gzip size?

Parsed Size: Uncompressed size of the JS and CSS files. This much code needs to be parsed and stored in memory.
Gzip Size: Compressed size of the JS and CSS files. This much data needs to be downloaded over network.

Generated by performance advisor bot at iscalypsofastyet.com.

[taipeicoder]

Nice improvements! 👍

[arthur791004]

Nice improvement! Thanks for taking care of a11y 💯