[shadetheory]

Adds a GitHub Actions workflow that runs roave/backward-compatibility-check (MIT) to catch public API changes before they ship.

When it runs

• On pull requests: compares HEAD against the latest vX.Y.Z tag.
• On v* tag pushes: compares the new tag against the previous release tag. A new major version is skipped, since breaking changes are expected there.
• If there is no earlier release tag to compare against, the job skips.

How it is installed
The tool is installed with composer global require into a job-local COMPOSER_HOME under the runner temp dir, so composer.json is unchanged. That job-local config also sets audit.block-insecure to false so older tagged releases can install their pinned dependencies for the comparison. Nothing else in the repo uses that setting.

Baseline
.roave-backward-compatibility-check.xml ignores only changes reported on the Symfony and Laravel console base classes that the package commands extend (getDefaultName()/getDefaultDescription() removed upstream, and configure()/initialize()/interact() gaining a void return type). The file is export-ignored in .gitattributes so it stays out of the dist archive.

Changes to the package's own API are still reported. For example, comparing v3.0.0 to v3.1.0 goes from 9 reported changes to these 4:

• GithubOAuth::$clientId, $clientSecret and $redirectUrl changed from string to ?string
• GithubOAuth::getAuthorizationUrl() gained a $state parameter

Checked locally

• v3.0.0 to v3.1.0: 9 changes without the baseline, 4 with it (the GithubOAuth ones above)
• v3.1.0 to HEAD: no backward incompatible changes
• pint --test, phpstan, pest (238 passed), actionlint, and the lean package validator all pass

[lexi-chief-of-staff]

Ship it.

• Local verification covers v3.0.0..v3.1.0 (baseline reduces noise to the four GithubOAuth changes) and v3.1.0..HEAD (clean).
• Workflow skips on first release and on major bumps, as documented.
• Baseline and export-ignore are correctly scoped; no changes to package API are suppressed.

[shadetheory]

Quality Gate: success

All quality checks passed.

Quality Check Results

All tools passed without violations.