Post Author: Add help text linking to profile screen

[dhaval-parekh]

What?

Closes #17364

Adds help text below the author selector in the post Author flyout: "You can edit your display name in your profile." — where "your profile" links to profile.php (opens in a new tab).

Why?

The author dropdown only shows display names. When multiple users share the same display name they are indistinguishable, and it isn't obvious where the shown name comes from or how to change it.

The original request was to append the username (as the classic editor did), but the username field is intentionally only exposed in the edit context of the REST API, and exposing new user data was ruled out in the issue discussion. The settled direction (see #17364 (comment) — jasmussen's mockup) is to add descriptive help text pointing users at the Display Name setting on their profile instead.

How?

• New AuthorHelpText component (packages/editor/src/components/post-author/help-text.js) using createInterpolateElement for the translatable string and Link from @wordpress/ui with openInNewTab for the profile link.
• Passed via the existing help prop on both variants of the selector: SelectControl (≤ 25 users) and ComboboxControl (> 25 users), so it renders below the field in both cases.
• Since PostAuthor lives in @wordpress/editor, the change applies to the post editor and both site editors automatically.

Testing Instructions

1. Open a post or page in the editor.
2. Open the Settings sidebar → Post/Page tab.
3. Click the author name to open the Author flyout.
4. Confirm the help text "You can edit your display name in your profile." renders below the dropdown, with "your profile" as a link.
5. Click the link — it should open the wp-admin Profile screen (profile.php) in a new tab.
6. To test the combobox variant, create 26+ users (e.g. npm run wp-env run cli -- wp user generate --role=author --count=30) and repeat steps 1–5, The flyout now renders a combobox with the same help text.

Testing Instructions for Keyboard

1. In the editor, press Ctrl+Shift+, (⌘+Shift+, on Mac) to open the Settings sidebar, and navigate to the Post/Page tab.
2. Tab to the author button and press Enter to open the flyout.
3. Tab past the dropdown to the "your profile" link — it should receive visible focus and announce "(opens in a new tab)".
4. Press Enter — the Profile screen opens in a new tab.

Screenshots or screencast

Label	Before	After
SelectControl ( Less than 25 users )
ComboboxControl (More than 25 users)

Use of AI Tools

• AI assistance: Yes
• Tool(s): Claude Code (Claude Fable 5)
• Used for: Implementation Approach, Code Review, Local Verification, PR Description/Docs.

[github-actions]

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Unlinked contributors: dhaval-parekh, yanksyoon.

Co-authored-by: draganescu <andraganescu@git.wordpress.org>
Co-authored-by: noisysocks <noisysocks@git.wordpress.org>
Co-authored-by: TimothyBJacobs <timothyblynjacobs@git.wordpress.org>
Co-authored-by: abhi3315 <abhi3315@git.wordpress.org>
Co-authored-by: Mamaduka <mamaduka@git.wordpress.org>
Co-authored-by: coderGtm <gautam23@git.wordpress.org>
Co-authored-by: jasmussen <joen@git.wordpress.org>
Co-authored-by: TwisterMc <twistermc@git.wordpress.org>

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[github-actions]

👋 Thanks for your first Pull Request and for helping build the future of Gutenberg and WordPress, @dhaval-parekh! In case you missed it, we'd love to have you join us in our Slack community.

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[aduth]

Hey 👋 I wanted to give you a heads-up since this pull request adds new files containing JSX.

#80123 enables an ESLint rule that requires that files containing JSX must use the .tsx file extension. This is in line with coding guidelines expecting new code to be written as TypeScript.

What you'll need to do: You'll need to rename any new files containing JSX to use the .tsx file extension. This may also require you to address type errors that were not previously caught due to the use of the .js file extension.

This comment is automated, based on pull requests with recent activity that contain affected .js or .jsx files. But if you have any questions or if I can help with the migration in any way, please let me know and I'll do my best to help!