Tooltip: Use md border radius for portaled popups.

[jameskoster]

What

Updates tooltip border radius from sm (2px) to md (4px) in both @wordpress/ui and @wordpress/components.

• @wordpress/ui: packages/ui/src/tooltip/style.module.css
• @wordpress/components: packages/components/src/tooltip/style.scss — replaces legacy $radius-small with var(--wpds-border-radius-md)

Why

Tooltips are portaled overlay surfaces, like menus and popovers. As discussed in #78913 that role maps to md, not sm radius. Using sm put tooltips on the same step as compact controls (buttons, inputs), which breaks the intended hierarchy between triggers and floating UI.

How

1. Switch tooltip popup styles to --wpds-border-radius-md in both packages.
2. Leave trigger/control styling unchanged — buttons and icon buttons stay on sm.
3. Native tooltip styling is unchanged; it already uses 4px, which matches md.

Screenshots

Before	After

Test plan

• Storybook → Design System/Components/Tooltip — popup corners use 4px radius
• Block editor / admin — legacy @wordpress/components tooltips match the updated radius
• Confirm tooltip triggers (buttons, icon buttons) are unchanged at sm

[github-actions]

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Co-authored-by: jameskoster <jameskoster@git.wordpress.org>
Co-authored-by: ciampo <mciampini@git.wordpress.org>
Co-authored-by: juanfra <juanfra@git.wordpress.org>

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[github-actions]

Size Change: +35 B (0%)

Total Size: 8.21 MB

📦 View Changed

Filename	Size	Change
build/modules/boot/index.min.js	51.8 kB	-1 B (0%)
build/modules/content-types/index.min.js	158 kB	+4 B (0%)
build/scripts/block-directory/index.min.js	42.9 kB	-1 B (0%)
build/scripts/block-editor/index.min.js	379 kB	+5 B (0%)
build/scripts/edit-post/index.min.js	51.9 kB	-1 B (0%)
build/scripts/edit-site/index.min.js	296 kB	+3 B (0%)
build/scripts/editor/index.min.js	463 kB	+2 B (0%)
build/scripts/media-utils/index.min.js	113 kB	+1 B (0%)
build/styles/components/style-rtl.css	18 kB	+6 B (+0.03%)
build/styles/components/style-rtl.min.css	14.9 kB	+6 B (+0.04%)
build/styles/components/style.css	18.1 kB	+5 B (+0.03%)
build/styles/components/style.min.css	14.9 kB	+6 B (+0.04%)

_{compressed-size-action}

[github-actions]

Flaky tests detected in 6a904ea.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/27021815986
📝 Reported issues:

• [Flaky Test] Should save the changes #78689 in /test/e2e/specs/editor/plugins/wp-editor-meta-box.spec.js
• [Flaky Test] shouldn't conflict with server-side autosave #78706 in /test/e2e/specs/editor/various/autosave.spec.js
• [Flaky Test] shows post-locked modal when document size limit is exceeded #78753 in /test/e2e/specs/editor/collaboration/http-only/collaboration-document-size-lock.spec.ts

[ciampo]

LGTM 🚀

Let's also review the docs about the DS border radius tokens in case there's an opportunity to make them even clearer about how they should be applied (what UI elements for each size) — although it looks we're already discussing a similar change in #78913.

[juanfra]

LGTM. Code looks good and it tests well 👍

tooltip-border-radius-2.mp4

tooltip-border-radius.mp4

[jameskoster]

Thanks for reviews ❤️