fix: remove git commits from release workflow, auto-increment beta from npm

[MQ37]

Summary

• Removes all git commit, tag, and push steps to avoid branch protection conflicts (GH013)
• Version bump is ephemeral — only lives in the published npm package
• GitHub release is created from github.sha without pushing tags
• Beta version auto-increments from the latest published beta on npm (e.g. if 0.1.11-beta.0 exists, next run produces 0.1.11-beta.1)