feat: improve iOS input outlines and supporting text

[rdlabo]

Summary

• add an iOS outline appearance for ion-input and ion-textarea
• stack labels above outlined controls and align their focus and invalid colors with the border
• tune outlined field dimensions, padding, placeholder opacity, and spacing
• handle helperText and errorText consistently for regular and outlined fields in inset lists
• hide empty supporting-text containers and remove row dividers only when a field needs supporting-text or outline spacing
• expand the inputs demo with standalone, helper, and error variants for both input and textarea
• verify the added demo variants with unit tests

Verification

• npm run build
• cd demo && npm test -- --watch=false (35 tests passed)

[github-actions]

Playwright test results

 90 passed

Details

 90 tests across 2 suites
 1 minute, 50 seconds
 20e6909
 This detailed result covers Ionic 9 only. Ionic 8 runs against the same screenshots in a separate matrix job; check the workflow run for both results. To update the screenshots, comment with /update-screenshots.

[github-actions]

📊 Ionic 9 Playwright Test Report

View the detailed Ionic 9 report: https://rdlabo-dev.github.io/ionic-theme-ios26/pr-124/

Ionic 8 runs against the same screenshots in a separate matrix job. View both results in the workflow run.

[github-actions]

📊 Ionic 9 Playwright Test Report

View the detailed Ionic 9 report: https://rdlabo-dev.github.io/ionic-theme-ios26/pr-124/

Ionic 8 runs against the same screenshots in a separate matrix job. View both results in the workflow run.

[rdlabo]

/update-screenshots

[github-actions]

📊 Ionic 9 Playwright Test Report

View the detailed Ionic 9 report: https://rdlabo-dev.github.io/ionic-theme-ios26/pr-124/

Ionic 8 runs against the same screenshots in a separate matrix job. View both results in the workflow run.

[github-actions]

❌ Failed to update screenshots.

Please check the workflow run for details.

[rdlabo]

/update-screenshots

[rdlabo]

/update-screenshots

[github-actions]

❌ Failed to update screenshots.

Please check the workflow run for details.

[github-actions]

📊 Ionic 9 Playwright Test Report

View the detailed Ionic 9 report: https://rdlabo-dev.github.io/ionic-theme-ios26/pr-124/

Ionic 8 runs against the same screenshots in a separate matrix job. View both results in the workflow run.

[github-actions]

❌ Failed to update screenshots.

Please check the workflow run for details.

[rdlabo]

/update-screenshots

[github-actions]

📊 Ionic 9 Playwright Test Report

View the detailed Ionic 9 report: https://rdlabo-dev.github.io/ionic-theme-ios26/pr-124/

Ionic 8 runs against the same screenshots in a separate matrix job. View both results in the workflow run.

[github-actions]

✅ Screenshots have been updated successfully!

The new screenshots have been committed to this PR.

[github-actions]

📊 Ionic 9 Playwright Test Report

View the detailed Ionic 9 report: https://rdlabo-dev.github.io/ionic-theme-ios26/pr-124/

Ionic 8 runs against the same screenshots in a separate matrix job. View both results in the workflow run.