Add typecheck script to all the workspaces that use TypeScript

[manzoorwanijk]

Following #44787, I noticed that there are many other workspaces that use TypeScript but are not type-checked. This PR addresses that.

Proposed changes:

• Add typecheck script to all the workspaces that use TypeScript
• The script is disabled for now for plugins/crm, packages/videopress and plugins/boost as they need extra effort to fix TS errors. Boost can be a bit challenging as it's a complete mess of a TS setup.

Other information:

• 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

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

Testing instructions:

• CI should be happy

[Copilot]

Pull Request Overview

This PR adds TypeScript type-checking capabilities to all workspaces that use TypeScript but were previously missing the typecheck script. This ensures consistent type validation across the entire codebase.

• Add standardized "typecheck": "tsc --noEmit" script to package.json files
• Include TypeScript as a dev dependency where needed
• Create tsconfig.json for shared-extension-utils package
• Update TypeScript version in external-media package to align with project standards

Reviewed Changes

Copilot reviewed 39 out of 40 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
projects/plugins/inspect/package.json	Adds typecheck script to inspect plugin
projects/plugins/crm/package.json	Adds typecheck script to CRM plugin
projects/plugins/boost/package.json	Adds typecheck script to Boost plugin
projects/packages/videopress/package.json	Adds typecheck script to VideoPress package
projects/packages/subscribers-dashboard/package.json	Adds typecheck script to subscribers dashboard
projects/packages/plugin-deactivation/package.json	Adds typecheck script to plugin deactivation package
projects/packages/external-media/package.json	Updates TypeScript version to 5.8.3
projects/packages/explat/package.json	Adds typecheck script to explat package
projects/packages/backup/package.json	Adds typecheck script to backup package
projects/js-packages/*/package.json	Adds typecheck scripts and TypeScript dependencies to various JS packages
projects/js-packages/shared-extension-utils/tsconfig.json	Creates TypeScript configuration file
/changelog/	Adds changelog entries for all modified packages

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.
You can also share your feedback on Copilot code review for a chance to win a $100 gift card. Take the survey.}

[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 or WordPress.com Site Helper), and enable the add/typecheck-script-to-ts-workspaces branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack add/typecheck-script-to-ts-workspaces

bin/jetpack-downloader test jetpack-mu-wpcom-plugin add/typecheck-script-to-ts-workspaces

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 a "[Type]" label (Bug, Enhancement, Janitorial, Task).
  
• ✅ 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!

---

Boost 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.

---

Inspect 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.

---

Classic Theme helper plugin 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

This PR did not change code coverage!

That could be good or bad, depending on the situation. Everything covered before, and still is? Great! Nothing was covered before? Not so great. 🤷

Full summary · PHP report · JS report