chore(icons): repoint ui icon consumers

[cdransf]

Description

Repoints CloseButton, MessageSources, and ResponseStatus off the pre-RFC icon/elements/ module onto <swc-ui-icon>, matching the Accordion POC. Deletes the now-unused iconForSize Storybook helper (Badge stories now call icon/elements functions directly). Removes <swc-icon>'s stale @status internal tag. Adds close-button's first VRT coverage (base + custom-properties). icon/elements/ itself is kept for now, it still backs <swc-icon>'s public export and docs; full retirement is a later phase.

Motivation and context

RFC Phase 1: repoint any component rendering a UI icon internally onto <swc-ui-icon>, no unsafeSVG remaining.

Related issue(s)

• Jira: SWC-2438, Phase 1

Screenshots (if appropriate)

No API changes. Note: CloseButton's cross icon now uses the RFC's fixed size-to-step map instead of its old ad hoc numbering, so l/xl may render a slightly different glyph. Check the new close-button.vrt.ts snapshot against Golden Hash.

Author's checklist

• I have read the CONTRIBUTING and PULL_REQUESTS documents.
• I have reviewed the Accessibility Practices for this feature.
• I have added automated tests to cover my changes.
• I have included a well-written changeset if my change needs to be published.
• I have included updated documentation if my change required it.

Reviewer's checklist

• Includes a Github Issue with appropriate flag or Jira ticket number without a link
• Includes thoughtfully written changeset if changes suggested include patch, minor, or major features
• Automated tests cover all use cases and follow best practices for writing
• Validated on all supported browsers
• All VRTs are approved before the author can update Golden Hash

Manual review test cases

• Close Button: check cross icon at every size, and under hover/focus/active, no distortion or regression.
• Conversational AI/Message sources and Response status: toggle expand/collapse, chevron rotates as before.
• Badge Playground: select each icon-slot option (Checkmark, Cross, Alert), confirm render, no console errors.

Device review

• Did it pass in Desktop?
• Did it pass in (emulated) Mobile?
• Did it pass in (emulated) iPad?

Accessibility testing checklist

• Keyboard: Tab to Close Button, expect focus ring; Enter/Space fires click (unchanged). Same for the Message sources/Response status toggle buttons; expand/collapse works, focus stays put.
• Screen reader: Close Button announces accessible-label only, icon stays silent (aria-hidden by default via IconBase). Toggle buttons announce label + aria-expanded; chevron stays silent. No behavior change from before this PR.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 8bf9cbe

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

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[github-actions]

📚 Branch Preview Links

• Storybook (Gen2, dev mode)
• Storybook (Gen2, prod mode)
• Documentation Site (Gen1)
• Storybook (Gen1)

🔍 Gen1 Visual Regression Test Results

When a visual regression test fails (or has previously failed while working on this branch), its results can be found in the following URLs:

• Spectrum | Light | Medium | LTR
• Spectrum | Dark | Large | RTL
• Express | Light | Medium | LTR
• Express | Dark | Large | RTL
• Spectrum-two | Light | Medium | LTR
• Spectrum-two | Dark | Large | RTL
• High Contrast Mode | Medium | LTR

Deployed to Azure Blob Storage: pr-6567

If the changes are expected, update the current_golden_images_cache hash in the circleci config to accept the new images. Instructions are included in that file.
If the changes are unexpected, you can investigate the cause of the differences and update the code accordingly.