feat(icon): remove modifiers from the API [SWC-1264]

[castastrophe]

Description

This update removes --mod-icon-* custom property hooks per SWC-1264, see also the RFC for extensible styling. Class selectors and variants remain unchanged; stories were refreshed to match the current API.

• Remove all --mod-icon-* custom property hooks.
• Reduces unnecessary re-mapping of custom properties in favor of using them directly

Breaking change: the --mod-icon-* override layer is removed. Consumers should set --spectrum-icon-* variables directly where customization as needed.

Related issue(s)

• fixes SWC-1264

Author's checklist

• I have read the CONTRIBUTING and PULL_REQUESTS documents.
• I have reviewed the Accessibility Practices for this feature, see: Aria Practices
• I have added automated tests to cover my changes (or confirmed existing coverage is sufficient for styling-only 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 passing or approved

Validation steps

• No visual or behavioral changes compared to the current spectrum-two baseline.

Regression testing

Validate:

1. The documentation pages for at least two other components are still loading, including:

   • The pages render correctly, are accessible, and are responsive.

2. If components have been modified, VRTs have been run on this branch:

   • VRTs have been run and looked at.
   • Any VRT changes have been accepted (by reviewer and/or PR author), or there are no changes.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 945da3b

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.

This PR includes changesets to release 12 packages

Name	Type
@spectrum-css/alertdialog	Major
@spectrum-css/asset	Major
@spectrum-css/assetcard	Major
@spectrum-css/assetlist	Major
@spectrum-css/avatar	Major
@spectrum-css/badge	Major
@spectrum-css/miller	Major
@spectrum-css/well	Major
@spectrum-css/page	Major
@spectrum-css/icon	Major
@spectrum-css/bundle	Patch
@spectrum-css/preview	Patch

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[github-actions]

📚 Branch preview

PR #4288 has been deployed to Azure Blob Storage: https://spectrumcss.z13.web.core.windows.net/pr-4288/index.html.

[github-actions]

File metrics

Summary

Total size: 1.41 MB^*
✅ No change in file sizes

Package	Size	Minified	Gzipped
alertbanner	6.06 KB	5.80 KB	1.33 KB
icon	12.18 KB	11.28 KB	1.49 KB
table	47.13 KB	44.91 KB	5.31 KB
tag	20.73 KB	19.83 KB	2.79 KB

File change details

alertbanner

Filename	Head	Minified	Gzipped	Compared to base
index.css	6.06 KB	5.80 KB	1.33 KB	🔴 ⬆ 0.01 KB
metadata.json	3.62 KB	-	-	🔴 ⬆ 0.01 KB

icon

Filename	Head	Minified	Gzipped	Compared to base
index.css	12.18 KB	11.28 KB	1.49 KB	🟢 ⬇ 0.57 KB
metadata.json	6.59 KB	-	-	🟢 ⬇ 0.27 KB

table

Filename	Head	Minified	Gzipped	Compared to base
index.css	47.13 KB	44.91 KB	5.31 KB	🟢 ⬇ 0.06 KB
metadata.json	22.04 KB	-	-	🟢 ⬇ 0.02 KB

tag

Filename	Head	Minified	Gzipped	Compared to base
index.css	20.73 KB	19.83 KB	2.79 KB	🔴 ⬆ 0.01 KB
metadata.json	10.29 KB	-	-	🔴 ⬆ 0.01 KB

* Size is the sum of all main files for packages in the library.
* An ASCII character in UTF-8 is 8 bits or 1 byte.