fix(pie-button): DSW-3684 apply width 100% to host when isFullWidth is set

[raoufswe]

Describe your changes (can list changeset entries if preferable)

• Applied width: 100% to the pie-button host when isFullWidth is set, ensuring the component correctly spans the full available width when nested inside a flex container.
• This change exposed an issue where hasStackedActions caused buttons to stretch to full width on desktop, instead of only on narrow screens. This was previously masked by isFullWidth not working correctly and the fix is to override this behavior on desktop.

Author Checklist (complete before requesting a review, do not delete any)

• I have performed a self-review of my code.
• I have added thorough tests where applicable (unit / component / visual).
• I have reviewed the PIE Storybook/PIE Docs PR preview.
• I have reviewed visual test updates properly before approving.
• If changes will affect consumers of the package, I have created a changeset entry.
• [-] If a changeset file has been created, I have tested these changes in PIE Aperture using the /test-aperture command.
• I have filled out the DS Review Tracker checklist (Moving PR to "Ready to Review")

Not-applicable Checklist items

Please move any Author checklist items that do not apply to this pull request here.

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Testing

How do I test my changes?

Task	Link
Aperture PR	🔗
NextJS 15 deployment	🔗
NextJS 14 deployment	🔗
Nuxt 3 deployment	🔗
Vanilla deployment	🔗

Reviewer checklists (complete before approving)

Mark items as [-] N/A if not applicable.

Reviewer 1

• I have reviewed the PIE Storybook/PIE Docs PR preview.
• I have verified that all acceptance criteria for this ticket have been completed.
• I have reviewed the Aperture changes (if added)
• If there are visual test updates, I have reviewed them.

Reviewer 2

• I have reviewed the PIE Storybook/PIE Docs PR preview.
• I have verified that all acceptance criteria for this ticket have been completed.
• I have reviewed the Aperture changes (if added)
• If there are visual test updates, I have reviewed them.

[changeset-bot]

🦋 Changeset detected

Latest commit: 57000ea

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

This PR includes changesets to release 9 packages

Name	Type
@justeattakeaway/pie-button	Patch
@justeattakeaway/pie-cookie-banner	Patch
@justeattakeaway/pie-modal	Patch
@justeattakeaway/pie-notification	Patch
@justeattakeaway/pie-toast	Patch
@justeattakeaway/pie-webc	Patch
@justeattakeaway/pie-toast-provider	Patch
@justeattakeaway/pie-docs	Patch
@justeattakeaway/pie-storybook	Patch

Not sure what this means? Click here to learn what changesets are.

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

[pie-design-system-bot]

	Fails
🚫	You have unchecked checklist items outside the "Not-applicable Checklist items" section. Please ensure all unchecked checkboxes are moved to the appropriate section.
🚫	You have unchecked checklist items in Reviewer 1's section. Please ensure all items are addressed before approval.
🚫	You have unchecked checklist items in Reviewer 2's section. Please ensure all items are addressed before approval.

Generated by 🚫 dangerJS against 57000ea

[fernandofranca]

The cookie banner buttons layout is looking a bit off atm

[raoufswe]

@copilot are you there?