Add Yoast SEO integration for media pages site health check

[obenland]

Summary

Adds a Yoast SEO integration that creates a site health check to ensure media pages are enabled when media attachments are configured for ActivityPub federation.

Fixes #2134

Proposed changes:

• New Yoast_Seo integration class: Checks if Yoast SEO's "Enable media pages" setting is properly configured for ActivityPub
• Conditional activation: Only runs when both Yoast SEO is active AND attachment post type is supported by ActivityPub
• Site health integration: Adds a dedicated site health test that:
  • Shows "good" status (green) when media pages are enabled
  • Shows "recommended" status (orange) when media pages are disabled, with instructions to enable them
• Direct settings link: Provides a clickable link to the exact Yoast SEO settings page for easy configuration
• Comprehensive tests: Full test coverage including attachment support detection, media pages status checking, and site health test scenarios

Why this change is needed:

When Yoast SEO's media pages are disabled, WordPress attachment URLs redirect to the media file itself rather than displaying an attachment page. This breaks ActivityPub federation of media because:

1. ActivityPub clients expect to find structured data on attachment pages
2. Media interactions (likes, shares, comments) need a proper page to target
3. The media becomes unfederated even when attachment post type is enabled

Testing instructions:

1. Install Yoast SEO plugin
2. Enable attachment post type in ActivityPub settings
3. Go to Tools > Site Health > Info tab
4. Check the site health tests - you should see "Yoast SEO Media Pages Test"
5. Try both scenarios:
   • Yoast media pages enabled: Should show green "good" status
   • Yoast media pages disabled: Should show orange "recommended" status with link to settings

Changelog entry

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Changelog Entry Details

Significance

• Minor

Type

• Added - for new features

Message

Add Yoast SEO integration for media pages site health check

[Copilot]

Pull Request Overview

This PR adds Yoast SEO integration that provides a site health check to ensure media pages are properly configured when ActivityPub federation is enabled for media attachments.

• Adds new Yoast_Seo integration class with site health functionality
• Conditionally registers site health test only when both Yoast SEO is active and attachment post type is supported
• Provides actionable feedback with direct links to Yoast SEO settings for configuration

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
integration/class-yoast-seo.php	New integration class implementing site health tests for Yoast SEO media pages configuration
integration/load.php	Adds conditional initialization of Yoast SEO integration when plugin is detected
tests/integration/class-test-yoast-seo.php	Comprehensive test coverage for the new integration including edge cases and different configuration scenarios

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