AI Assistant: add feature settings controls

[kat3samsin]

Fixes #

Proposed changes

• Add a centralized Jetpack_AI_Settings registry for the Jetpack AI master switch and per-feature toggles.
• Add wpcom/v2/jetpack-ai/feature-settings for reading and updating AI feature settings.
• Wire the settings gates into AI Assistant, AI Chat, AI Content Lens/excerpt, Image Studio, and AI Sidebar feature suggestions.
• Add PHPUnit coverage for the settings gates, REST payload/update behavior, AI Content Lens gating, Image Studio gating, and sidebar suggestions.

Related product discussion/links

• None included.

Does this pull request change what data or activity we track or use?

Yes. It registers and syncs site-local boolean options for Jetpack AI feature settings (jetpack_ai_enabled, jetpack_ai_writing_assistant_enabled, jetpack_ai_image_editor_enabled, jetpack_ai_image_label_enabled, jetpack_ai_excerpt_enabled) so WordPress.com can read the site's AI feature-toggle state. It does not add new event tracking.

Testing instructions

1. In a Jetpack test environment with this branch active, authenticate as an admin user and request GET /wp-json/wpcom/v2/jetpack-ai/feature-settings.
2. Confirm the response includes host_allows_ai, is_connected, plan.supports_ai, plan.supports_search, master_enabled, and feature entries for writing assistant, image editor/image label, SEO enhancer, excerpt, and AI Search.
3. Send a partial POST /wp-json/wpcom/v2/jetpack-ai/feature-settings payload such as { "master_enabled": false, "features": { "excerpt": false, "seo_enhancer": { "enabled": true } } }.
4. Confirm only the submitted options change and the response returns the fresh settings shape.
5. Toggle individual feature options off and confirm their corresponding editor entry points or sidebar suggestions no longer load.

Local validation run:

• git diff --check
• php -l on all changed PHP files

Not run locally:

• Full Jetpack PHPUnit. Docker is not running locally, and Composer PHPUnit requires WORDPRESS_DEVELOP_DIR in this checkout.
• Husky commit/push hooks. The active local pnpm is 10.30.3; this repo currently requires ^11.5.0, so the hooks failed before running repository checks.

[github-actions]

Are you an Automattician? Please test your changes on all WordPress.com environments to help mitigate accidental explosions.

• To test on WoA, go to the Plugins menu on a WoA dev site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin (Jetpack), and enable the add/jetpack-ai-feature-settings branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack add/jetpack-ai-feature-settings

Interested in more tips and information?

• In your local development environment, use the jetpack rsync command to sync your changes to a WoA dev blog.
• Read more about our development workflow here: PCYsg-eg0-p2
• Figure out when your changes will be shipped to customers here: PCYsg-eg5-p2

[github-actions]

Thank you for your PR!

When contributing to Jetpack, we have a few suggestions that can help us test and review your patch:

• ✅ Include a description of your PR changes.
  
• ✅ Add a "[Status]" label (In Progress, Needs Review, ...).
  
• ✅ Add testing instructions.
  
• ✅ Specify whether this PR includes any changes to data or privacy.
  
• ✅ Add changelog entries to affected projects
  

This comment will be updated as you work on your PR and make changes. If you think that some of those checks are not needed for your PR, please explain why you think so. Thanks for cooperation 🤖

---

Follow this PR Review Process:

1. Ensure all required checks appearing at the bottom of this PR are passing.
2. Make sure to test your changes on all platforms that it applies to. You're responsible for the quality of the code you ship.
3. You can use GitHub's Reviewers functionality to request a review.
4. When it's reviewed and merged, you will be pinged in Slack to deploy the changes to WordPress.com simple once the build is done.

If you have questions about anything, reach out in #jetpack-developers for guidance!

---

Jetpack plugin:

No scheduled milestone found for this plugin.

If you have any questions about the release process, please ask in the #jetpack-releases channel on Slack.

[jp-launch-control]

Code Coverage Summary

Cannot generate coverage summary while tests are failing. 🤐

Please fix the tests, or re-run the Code coverage job if it was something being flaky.

Full summary · PHP report · JS report