feat(author-profile): add block variations for layout selection

[rbcorrales]

All Submissions:

• Have you followed the Newspack Contributing guideline?
• Does your code follow the WordPress' coding standards and VIP Go coding standards?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

When inserting the Author Profile block in a block theme, publishers can now choose from four layout variations: Default (avatar left), Avatar right, Centered, and Compact (no avatar). Each variation provides the same set of author fields so publishers can remove what they don't need without worrying about losing fields they can't add back.

After choosing a layout, a "Change layout" button in the toolbar lets publishers switch to a different variation. A confirmation dialog warns that switching will replace the current block content. A "Reset" button restores the current variation's original layout.

Closes NPPD-1221.

How to test the changes in this Pull Request:

1. Open a post editor in a block theme environment.
2. Insert a new Author Profile block and verify a layout picker appears with 4 options.
3. Select each variation and verify the inner blocks match the expected layout.
4. In the list view and sidebar, verify each variation shows its name (e.g., "Author Profile (Centered)") with a blue icon.
5. Click "Change layout" in the toolbar and verify the currently active variation is highlighted.
6. Click a different variation, confirm the dialog appears, accept it, and verify inner blocks are replaced.
7. Cancel the dialog on a different attempt and verify nothing changes.
8. Remove some inner blocks, then click "Reset" and verify the block resets to the current variation's full template.
9. Add the Author Profile block in the site editor and verify the variation picker and layout switching work correctly.

Other information:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes, as applicable?
• Have you successfully ran tests with your changes locally?

[Copilot]

Pull request overview

This pull request adds block variation support to the Author Profile block, enabling publishers to choose from four different layout options when inserting the block in a block theme. The implementation follows WordPress block editor conventions by using the standard block variations API along with custom variation switcher UI for changing layouts after initial selection.

Changes:

• Adds four layout variations (Default, Avatar right, Centered, and Compact) with visual picker UI
• Refactors template definitions into a separate module with shared constants for reusability
• Implements variation switching with confirmation dialog to prevent accidental content loss

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
src/blocks/author-profile/variations.js	Defines four block variations with custom icons and layout configurations
src/blocks/author-profile/templates.js	Extracts and organizes block templates with shared constants for all variations
src/blocks/author-profile/index.js	Registers variations with the block
src/blocks/author-profile/edit.js	Adds variation picker, switcher modal, and auto-populate logic
src/blocks/author-profile/block.json	Adds variation attribute to track selected layout
src/blocks/author-profile/editor.scss	Styles for the variation switcher modal UI

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[Copilot]

Pull request overview

Copilot reviewed 5 out of 6 changed files in this pull request and generated 3 comments.

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