feat(helper-text): port <pf-v5-helper-text> to <pf-v6-helper-text> element

[adamjohnson]

Summary

• Removes <pf-v5-helper-text>
• Ports <pf-v5-helper-text> to <pf-v6-helper-text> web component for PatternFly v6
• Displays contextual feedback or validation messages for form fields
• Supports variant (default/indeterminate/warning/success/error), has-icon, dynamic, and screen-reader-text attributes
• Built-in SVG icons from @patternfly/react-icons (rh-ui-minus, rh-ui-warning-fill, rh-ui-check-circle-fill, rh-ui-error-fill)
• Dark mode support via light-dark() CSS fallbacks
• Demos: basic (index), with-custom-icons, multiple, dynamic

Closes #3012

Intentional divergences from React

• Single element instead of React's HelperText (container) + HelperTextItem (item) pair; use plain HTML wrappers with aria-live for grouping
• has-icon attribute for opt-in icon display (React auto-shows icons for non-default variants)
• icon slot replaces React's icon prop (ReactNode → slotted markup)
• screen-reader-text attribute maps to React's screenReaderText prop
• dynamic attribute exposes React's internal .pf-m-dynamic CSS modifier class
• Container props (component, isLiveRegion, aria-label) not implemented; users apply these directly on wrapper elements
• No dependency on <pf-v5-icon> — uses inline SVG icons

Test plan

• npm run test passes
• Demos render correctly at localhost:8000
• All variant styles (colors, font weight, icons) visually match patternfly.org
• Dark mode colors correct when switching color scheme
• Screen reader text announces variant status for non-default variants
• Custom screen-reader-text overrides default announcement
• Empty screen-reader-text="" suppresses announcement
• Custom icon slot displays slotted SVG in place of default icon
• Dynamic demo shows aria-live container with mixed success/error items

Assisted-By: Claude

[changeset-bot]

🦋 Changeset detected

Latest commit: 205eb07

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

This PR includes changesets to release 1 package

Name	Type
@patternfly/elements	Major

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[github-actions]

✅ Commitlint tests passed!

More Info

{
  "valid": true,
  "errors": [],
  "warnings": [],
  "input": "feat(helper-text): port `<pf-v5-helper-text>` to `<pf-v6-helper-text>` element"
}

[github-actions]

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