perf(SelectPanel): Document acceptable :has() selector usage

[mattcosta7]

Closing - Documentation only, no code change

This PR only adds a comment explaining why an existing :has() selector is acceptable. No actual code or behavior changes.

+  /*
+   * NOTE: Uses descendant :has() - input is not direct child of TextInputWrapper
+   * due to TextInputInnerVisualSlot wrappers. This is acceptable performance
+   * as the search is scoped to this single element's subtree.
+   */

While the documentation is helpful, it doesn't warrant a patch release since there's no behavior change.

[changeset-bot]

🦋 Changeset detected

Latest commit: 096d1ab

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@primer/react	Patch

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[github-actions]

👋 Hi, this pull request contains changes to the source code that github/github-ui depends on. If you are GitHub staff, test these changes with github/github-ui using the integration workflow. Or, apply the integration-tests: skipped manually label to skip these checks.

[mattcosta7]

Closing - this only adds documentation comments with no code or behavior change.