Add changeset generator workflow for pull requests

[Copilot]

Summary

This PR adds a GitHub Agentic Workflow that automatically generates changeset files when a pull request becomes ready for review, streamlining the version management process.

Problem

Creating changesets manually for each pull request is:

• Time-consuming and easy to forget
• Prone to errors in format and version classification
• Inconsistent across contributors

Solution

A new workflow (.github/workflows/changeset-generator.md) that:

1. Triggers automatically when a PR is marked as "ready for review"
2. Analyzes the PR content using Claude AI to understand the changes
3. Determines the correct version bump (major/minor/patch) based on:
   • PR title and description keywords (feat:, fix:, BREAKING CHANGE, etc.)
   • Nature of the changes described
4. Generates a properly formatted changeset following the official changesets specification
5. Pushes the changeset directly to the current PR branch (commits it to the PR being reviewed)

Example

When a PR titled "feat: Add support for custom themes" is marked ready for review, the workflow will:

1. Analyze the PR content
2. Determine it's a new feature → minor version bump
3. Check package.json for the package name (e.g., "gh-aw")
4. Create .changeset/minor-add-custom-theme-support.md:

---
"gh-aw": minor
---

Add support for custom themes

This PR adds the ability to configure custom themes for the CLI output.

5. Commit and push the changeset file directly to the current PR branch

Configuration

• Engine: Claude AI for intelligent PR analysis
• Permissions: Minimal required (contents:read, pull-requests:read)
• Safe Outputs: Uses push-to-pull-request-branch to commit changes directly to the PR
• Timeout: 10 minutes

Benefits

✅ Automates changeset creation process
✅ Ensures consistent changeset format
✅ Reduces human error in version classification
✅ Integrates seamlessly with changesets tooling
✅ Saves developer time and mental overhead
✅ Changeset becomes part of the same PR (no separate PR needed)

Files Changed

• .github/workflows/changeset-generator.md - Workflow definition (4.4 KB)
• .github/workflows/changeset-generator.lock.yml - Compiled GitHub Actions workflow (168 KB)

Testing

• ✅ Workflow compiles successfully
• ✅ All unit tests pass
• ✅ make agent-finish validation complete
• ✅ Uses only allowed GitHub context expressions for security
• ✅ Code review passed

Resolves the need for automated changeset generation as specified in the issue requirements.

Original prompt

Generate a workflow that generates a changeset from the changes in a pull request when it becomes ready for review.

changeset spec and format: https://github.com/changesets/changesets/blob/main/docs/adding-a-changeset.md

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[pelikhan]

use push to pull request branch instead

[pelikhan]

@copilot use push to pull request branch instead

[Copilot]

Changed to use push-to-pull-request-branch in commit b4f7e8b. The workflow now pushes the changeset directly to the PR branch instead of creating a separate PR.

[pelikhan]

@copilot use copilot

[pelikhan]

@copilot merge main, format, lint, recompile