Update activeIndicatorLine to grow with content

[adierkens]

Changelog

Changed

Updates the active indicator lines for ActionList and FilteredActionList to follow the content size:

Before	After

The active highlight remains the same 4px offset as before, just now carries over to all content sizes.

Rollout strategy

• Patch release
• Minor release
• Major release; if selected, include a written rollout or migration plan
• None; if selected, include a brief description as to why

Testing & Reviewing

Merge checklist

• Added/updated tests
• Added/updated documentation
• Added/updated previews (Storybook)
• Changes are SSR compatible
• Tested in Chrome
• Tested in Firefox
• Tested in Safari
• Tested in Edge
• (GitHub staff only) Integration tests pass at github/github (Learn more about how to run integration tests)

[changeset-bot]

🦋 Changeset detected

Latest commit: bd543d5

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

This PR includes changesets to release 2 packages

Name	Type
@primer/react	Minor
@primer/styled-react	Major

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

[Copilot]

Pull Request Overview

This PR updates the active indicator lines in ActionList and FilteredActionList components to dynamically grow with content height instead of using a fixed height. The change ensures that multi-line items display the indicator line properly across their full height while maintaining the same 4px offset.

Key Changes:

• Modified the CSS mixin to use dynamic height calculation based on content
• Added a new Storybook example story demonstrating the behavior with long, wrapping text items

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
packages/postcss-preset-primer/src/mixins/activeIndicatorLine.css	Changed from fixed positioning/height to dynamic height that grows with content
packages/react/src/FilteredActionList/FilteredActionList.examples.stories.tsx	Added new example story showcasing the indicator with long, wrapping text items
.changeset/bright-ravens-jog.md	Added changeset entry documenting the minor version update

[francinelucca]

it's ok if we don't but it we want this to have VRT, we should add it to e2e/components/* (noticed we don't have one for FilteredActionList, might be a good time to add one)

[adierkens]

Good call. Added FilteredActionList to the e2e snapshots

[primer-integration]

👋 Hi from github/github-ui! Your integration PR is ready: https://github.com/github/github-ui/pull/5941

[primer-integration]

🟢 ci completed with status success.