internal: Improve AGENTS.md with CI, changesets, and targeted test info

[ntucker]

Motivation

AGENTS.md was missing non-obvious context that coding agents need to work effectively — particularly around CI, changesets, and how to run targeted tests. Meanwhile, the documentation updates section and packages/AGENTS.md duplicated details already covered by skills.

Solution

Added to root AGENTS.md:

• CI section: CircleCI (PR validation) vs GitHub Actions (release/auxiliary)
• Changesets section with version-linking note
• Targeted test syntax with Jest project names (ReactDOM, Node, ReactNative)
• Pre-push verification command

Condensed:

• Documentation updates section → one-liner pointing to "packages-documentation" skill
• packages/AGENTS.md → one-liner pointing to "changeset" skill

Net effect: -10 lines, more useful information, less duplication with skills.

Open questions

N/A

Made with Cursor

---

Note

Low Risk
Docs-only changes with no impact to runtime behavior, build output, or CI configuration.

Overview
Updates root AGENTS.md with practical contributor guidance: how to run targeted Jest projects/tests, what CI runs in CircleCI vs GitHub Actions, and when/how to add changesets (including version-linked core packages).

Condenses duplicated guidance by replacing the detailed “Documentation Updates” section and most of packages/AGENTS.md with short pointers to the relevant skills docs.

^{Written by Cursor Bugbot for commit 1f4f6d2. This will update automatically on new commits. Configure here.}

[changeset-bot]

⚠️ No Changeset found

Latest commit: 1f4f6d2

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[github-actions]

Size Change: 0 B

Total Size: 80.5 kB

ℹ️ View Unchanged

Filename	Size
examples/test-bundlesize/dist/App.js	3.18 kB
examples/test-bundlesize/dist/polyfill.js	307 B
examples/test-bundlesize/dist/rdcClient.js	10.2 kB
examples/test-bundlesize/dist/rdcEndpoint.js	6.33 kB
examples/test-bundlesize/dist/react.js	59.7 kB
examples/test-bundlesize/dist/webpack-runtime.js	726 B

_{compressed-size-action}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.05%. Comparing base (70fddec) to head (1f4f6d2).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3777   +/-   ##
=======================================
  Coverage   98.05%   98.05%           
=======================================
  Files         151      151           
  Lines        2834     2834           
  Branches      555      555           
=======================================
  Hits         2779     2779           
  Misses         11       11           
  Partials       44       44           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.