Add RWX as a supported CI provider

[robinaugh]

Hey there folks - I work at RWX, a CI/CD company and Linear customer. One of the engineering teams using RWX asked about running linear-release on our platform, which prompted this docs guide on our side; I'm adding an examples folder here to mirror that.

Summary

• Add examples/rwx-continuous/ and examples/rwx-scheduled/ (removed per request)
• Surface RWX in the linear-release-setup skill (platform detection, examples table, secrets reminder) and the AI-setup paragraph in the README. (removed per request)
• Detect RWX=true in ci-env.ts so the User-Agent reports linear-release/x.y.z (rwx), matching the existing GitHub Actions / GitLab CI / CircleCI handling.

[axelniklasson]

Hi @robinaugh, thanks for taking the time to create this PR. I really appreciate you wanting to add in the examples, but we made a call to only include major CI providers in this repo (as it will otherwise be too many) but the user agent changes would be useful so if you wouldn't mind updating the PR to only include the changes in src I can then go ahead and land it. Thanks again!

[linear-code]

PR includes example files that maintainer has explicitly requested be removed

(High) The maintainer (@axel) has already requested in [dda77cec] that the examples/rwx-continuous/ and examples/rwx-scheduled/ directories be removed, keeping only the src/ci-env.ts user-agent change. The PR has not been updated to reflect this. This PR should not be merged in its current state until those files are dropped.

[linear-code]

Left some comments. The PR still includes the examples/ directories that @axel asked to be removed — the src/ci-env.ts user-agent change is the only part intended for merging, and the PR needs to be scoped down before it can land.

[robinaugh]

Hi @robinaugh, thanks for taking the time to create this PR. I really appreciate you wanting to add in the examples, but we made a call to only include major CI providers in this repo (as it will otherwise be too many) but the user agent changes would be useful so if you wouldn't mind updating the PR to only include the changes in src I can then go ahead and land it. Thanks again!

Yeah no problem @axelniklasson - I've updated this PR to only include the user agent detection. Please let me know if you'd like any additional changes. Thanks again!

[axelniklasson]

Thanks for updating!