fix(combobox): align slotted field label with standalone label

[aramos-adobe]

Description

Aligns the combobox slotted field label with standalone (typography, colors, sizes) and fixes picker button placement and disabled high-contrast styling.

This is also aims to align grid layout of the combobox referenced in SWC-1316

Motivation and context

The combobox uses FieldLabelMixin, which renders the label in shadow DOM. The slotted label’s CSS did not match the standalone <sp-field-label> component, and the picker button could misalign when a label was present. Disabled state in forced-colors also needed to use GrayText for the picker button.

Related issue(s)

• fixes [SWC-1320]

Screenshots (if appropriate)

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Still left TO-DO

• Fix side alignment of the label and picker button
• Remove border on .spectrum-PickerButton--quiet disabled state

Author's checklist

• I have read the CONTRIBUTING and PULL_REQUESTS documents.
• I have reviewed at the Accessibility Practices for this feature, see: Aria Practices
• 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.

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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

• Slotted label vs standalone: Combobox default story and "With standalone field label" story — slotted label (e.g. <span slot="field-label">) matches standalone <sp-field-label> in typography, spacing, and colors.

  1. Open Storybook → Combobox → Default and "With standalone field label".
  2. Compare label appearance; change size (s/m/l/xl), disabled, required.
  3. Expect slotted and standalone labels to look the same.

• Picker button alignment: Combobox with a slotted label — picker button stays aligned with the input row.

  1. Open Combobox → Default (or any story with a field label).
  2. Check that the chevron/button is vertically aligned with the input, not shifted.
  3. Expect no misalignment.

• Forced-colors disabled: Disabled combobox in high-contrast mode — label and picker button use GrayText.

  1. Enable forced-colors (e.g. DevTools → Rendering → "Emulate CSS media feature forced-colors: active" or Windows High Contrast).
  2. Open Combobox → With standalone field label, turn "disabled" on.
  3. Expect label and picker button (border/icon) to use GrayText.

• No regressions: Existing combobox stories (sizes, quiet, invalid, readonly, etc.) still look and behave correctly.

  1. Run through Combobox stories (Default, disabled, invalid, quiet, readonly, etc.).
  2. Expect no visual or behavioral regressions.

Device review

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

[changeset-bot]

⚠️ No Changeset found

Latest commit: f072ad7

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[nikkimk]

Looking good. I'm seeing some spacing differences between the label and the combobox we'll need to fix though.

[github-actions]

📚 Branch Preview Links

• Documentation Site (first-gen)
• Storybook (first-gen)
• Storybook (second-gen)

🔍 First Generation 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-6047

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If the changes are unexpected, you can investigate the cause of the differences and update the code accordingly.