v38: Move Banner to main export

[pksjce]

Closes https://github.com/github/primer/issues/5628

In this PR, we will move Banner component to the main export. I think it is well suited to recommend for migration from Flash component.
Any advise on how to measure it in terms of our new readyness scale? @adierkens @siddharthkp ?

As a companion to this I will create a path-to-green commit on github-ui where I will move all the imports from experimental to the main one.

[changeset-bot]

🦋 Changeset detected

Latest commit: 8f988df

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	Major
@primer/styled-react	Major

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[Copilot]

Pull Request Overview

This PR moves the Banner component from the experimental package to the main export, making it part of the stable public API. This change promotes the component's readiness status while maintaining backward compatibility and updating all related documentation and test references.

• Move Banner component exports from experimental to main package
• Update Storybook story titles from "Experimental/Components/Banner" to "Components/Banner"
• Update documentation and test references to reflect the new import path

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/react/src/index.ts	Adds Banner exports to main package and removes PointerBox exports
packages/react/src/experimental/index.ts	Removes Banner exports from experimental package
packages/react/src/Banner/Banner.stories.tsx	Updates story title from experimental to main components section
packages/react/src/Banner/Banner.features.stories.tsx	Updates story title from experimental to main components section
packages/react/src/Banner/Banner.examples.stories.tsx	Updates story title from experimental to main components section
packages/react/src/Banner/Banner.docs.json	Updates import path and story IDs for documentation
e2e/components/Banner.test.ts	Updates test story IDs to match new component location

[Copilot]

The removal of PointerBox exports appears to be unrelated to the Banner migration and may be an accidental change that could break existing imports.

See below for a potential fix:

export type {OverlayProps} from './Overlay'
export {default as PointerBox} from './PointerBox'

[github-actions]

👋 Hi, this pull request contains changes to the source code that github/github depends on. If you are GitHub staff, we recommend testing these changes with github/github using the integration workflow. Thanks!

[github-actions]

size-limit report 📦

Path	Size
packages/react/dist/browser.esm.js	90.45 KB (+0.7% 🔺)
packages/react/dist/browser.umd.js	90.61 KB (+0.68% 🔺)

[siddharthkp]

Any advise on how to measure it in terms of our new readyness scale? @adierkens @siddharthkp ?

The new scale is still a proposal, so we're using alpha/beta/stable for now.

Buuuut, if you want here are the 17 items in the current criteria today, each criterion is worth 1 point.