chore(claude): Add changelog updating to PR and standalone skills (#926)

## Summary

Integrates changelog updating into the Claude Code PR creation workflow
and adds a standalone `/update-changelogs` skill. Moves the changelog
documentation from the README into a dedicated file at
`docs/contributing/updating-changelogs.md` so it can be referenced by
both skills and human contributors.

- Add a mandatory "Update changelogs" phase (Phase 4) to the PR skill,
before PR creation
- Add a standalone `update-changelogs` skill for ad-hoc changelog
updates
- Move changelog documentation from `README.md` to
`docs/contributing/updating-changelogs.md` with minor wording
improvements
- Update `.gitignore` to track `docs/contributing/`

## Testing

These changes are to documentation and Claude Code skill definitions.
Verified that:
- The relative links from skill files to the changelog docs resolve
correctly
- The `.gitignore` change correctly tracks the new `docs/contributing/`
directory
- The README link to the extracted documentation is valid

🤖 Generated with [Claude Code](https://claude.com/claude-code)

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Low risk: changes are limited to documentation, Claude skill
instructions, and `.gitignore` rules with no runtime code or release
logic changes.
> 
> **Overview**
> Adds a mandatory **"Update changelogs"** phase to the
`.claude/skills/pr` workflow, requiring contributors to follow
`docs/contributing/updating-changelogs.md` and commit changelog updates
before running `gh pr create`.
> 
> Introduces a standalone `.claude/skills/update-changelogs` skill for
ad-hoc changelog updates, moves the changelog guidance from `README.md`
into `docs/contributing/updating-changelogs.md`, and updates
`.gitignore` so `docs/contributing/` is tracked.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
d4c0024. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: rekmarks

.claude/skills/pr/SKILL.md

@@ -107,14 +107,20 @@ Otherwise, after all launched subagents complete:
    - Abort
 4. If there are no blockers, briefly summarize the findings and proceed.
 
-## Phase 4: Create the PR
+## Phase 4: Update changelogs
 
-5. Run `gh pr create` to create a pull request. The PR body should include:
+**MANDATORY — DO NOT SKIP.** Each PR must update changelogs for all packages with consumer-facing changes.
+Read the instructions in [`docs/contributing/updating-changelogs.md`](../../../docs/contributing/updating-changelogs.md) and follow them to the letter.
+Commit the changes to the current branch with the commit message "docs: Update changelogs" before creating the PR.
+
+## Phase 5: Create the PR
+
+1. Run `gh pr create` to create a pull request. The PR body should include:
 
    - A brief narrative description of the PR
    - A summary of the changes (bullet points)
    - A brief description of how the code is tested (narrative, not a checklist)
 
    **If this is a stacked PR**, add `--draft` to create it as a draft PR.
 
-6. Return the PR URL and any relevant information. If a review was performed, include the review summary.
+2. Return the PR URL and any relevant information. If a review was performed, include the review summary.

.claude/skills/update-changelogs/SKILL.md

@@ -0,0 +1,10 @@
+---
+name: update-changelogs
+description: Updates changelogs for all packages with consumer-facing changes.
+---
+
+When asked to update changelogs, follow these steps:
+
+1. Read the instructions in [`docs/contributing/updating-changelogs.md`](../../../docs/contributing/updating-changelogs.md) and follow them to the letter.
+2. Commit the changes to the current branch with the commit message "docs: Update changelogs" before creating the PR.
+3. Return the commit hash and the commit message.

.gitignore

@@ -3,6 +3,7 @@ dist/
 coverage/
 docs/*
 !docs/*.md
+!docs/contributing
 
 # Logs
 logs

README.md

@@ -64,34 +64,7 @@ See [`packages/create-package/README.md`](packages/create-package/README.md).
 
 ### Updating changelogs
 
-Each package in this repo has a file named `CHANGELOG.md` which is used to
-record consumer-facing changes that have been published over time. All
-changelogs follow the ["Keep a Changelog"](https://keepachangelog.com/)
-specification (enforced by `@metamask/auto-changelog`).
-
-If a PR introduces a consumer-facing change to one or more packages, their changelogs must
-be updated. This is enforced by CI. When updating changelogs, keep the following in mind:
-
-- A changelog is not a git history; it is a summary of consumer-facing changes introduced by
-  a particular release.
-  - Consider each PR from the perspective of a consumer of an individual package. Changelog
-    entries may differ between packages.
-  - For example, if you're introducing feature X to package A, and it contains an incidental
-    change Y to package B, the package changelogs should reflect this.
-- Place new entries under the "Unreleased" section.
-- Place changes into categories. Consult the ["Keep a Changelog"](https://keepachangelog.com/en/1.1.0/#how) specification for the list.
-- Highlight breaking changes by prefixing them with `**BREAKING:**`.
-- Omit non-consumer facing changes from the changelog.
-- Do not simply reuse the commit message, but describe exact changes to the API or usable
-  surface area of the project.
-- Use a list nested under a changelog entry to enumerate more details about a change if need be.
-- Include links (e.g. `#123) to the pull request(s) that introduced each change.
-- Combine like changes from multiple pull requests into a single changelog entry if necessary.
-- Split disparate changes from the same pull request into multiple entries if necessary.
-- Omit reverted changes from the changelog.
-
-If your PR does not contain any consumer-facing changes, add the label `no-changelog`, and the
-changelog validation CI job will be skipped.
+See [`docs/contributing/updating-changelogs.md`](docs/contributing/updating-changelogs.md).
 
 ### Releasing
 

docs/contributing/updating-changelogs.md

@@ -0,0 +1,29 @@
+# Updating changelogs
+
+Each package in this repo has a file named `CHANGELOG.md` which is used to
+record consumer-facing changes that have been published over time. All
+changelogs follow the ["Keep a Changelog"](https://keepachangelog.com/)
+specification (enforced by `@metamask/auto-changelog`).
+
+If a PR introduces a consumer-facing change to one or more packages, their changelogs must
+be updated. This is enforced by CI. When updating changelogs, keep the following in mind:
+
+- A changelog is not a git history; it is a summary of consumer-facing changes introduced by
+  a particular release.
+  - Consider each PR from the perspective of a consumer of an individual package. Changelog
+    entries may differ between packages.
+  - For example, if you're introducing feature X to package A, and it contains an incidental
+    change Y to package B, the package changelogs should reflect this.
+  - Describe entries in natural language; do not simply reuse the commit message.
+- Unless you're cutting a new release, place new entries under the "Unreleased" section.
+- Place changes into categories. Consult the ["Keep a Changelog"](https://keepachangelog.com/en/1.1.0/#how) specification for the list.
+- Highlight breaking changes by prefixing them with `**BREAKING:**`.
+- Omit non-consumer facing changes from the changelog.
+- Use a list nested under a changelog entry to enumerate more details about a change if need be.
+- Include links (e.g. `#123) to the pull request(s) that introduced each change.
+- Combine like changes from multiple pull requests into a single changelog entry if necessary.
+- Split disparate changes from the same pull request into multiple entries if necessary.
+- Only included reverted changes if they were previously released.
+
+If your PR does not contain any consumer-facing changes, add the label `no-changelog`, and the
+changelog validation CI job will be skipped.