feat: Editor assets endpoint includes manifest data

[dcalhoun]

Close CMM-505. Close CMM-506. Add additional manifest data necessary for loading and caching assets within the mobile apps.

Inspired by https://github.com/wordpress-mobile/block-editor-assets-endpoint/pull/1.

Proposed changes:

• Add hash key for tracking when the endpoint return changes.
• Add styles_html and scripts_html keys for returning HTML for scripts and styles.
• Return array of asset URLs in styles and script keys for iterating and downloading assets.
• Add additional automated tests.

Other information:

• [x] Have you written new tests for your changes, if applicable?
• [ ] Have you checked the E2E test CI results, and verified that your changes do not break them?
• [ ] Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Jetpack product discussion

N/A

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

No

Testing instructions:

TBD

[github-actions[bot]]

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 feat/editor-assets-endpoint-includes-manifest-data branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack feat/editor-assets-endpoint-includes-manifest-data

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[bot]]

Thank you for your PR!

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---

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.
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---

Jetpack plugin:

The Jetpack plugin has different release cadences depending on the platform:

• WordPress.com Simple releases happen as soon as you deploy your changes after merging this PR (PCYsg-Jjm-p2).
• WoA releases happen weekly.
• Releases to self-hosted sites happen monthly:
  • Scheduled release: July 1, 2025
  • Code freeze: June 30, 2025

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

[jp-launch-control[bot]]

Code Coverage Summary

Coverage changed in 1 file.

File	Coverage	Δ%	Δ Uncovered
projects/plugins/jetpack/_inc/lib/core-api/wpcom-endpoints/class-wpcom-rest-api-v2-endpoint-block-editor-assets.php	167/172 (97.09%)	0.88%	0 💚

Full summary · PHP report · JS report

[dcalhoun]

Closing as this is no longer necessary given the latest client implementation in https://github.com/wordpress-mobile/GutenbergKit/pull/148.