> [!NOTE]
> This PR was written by Claude (Claude Code), not by @kylebarron.

Bumps `version` to `0.9.0-beta.1` in the root `package.json` and in
every `packages/*/package.json`, ready for a beta release. The publish
workflow sees `beta` in the version and publishes to npm under the
`beta` dist-tag, so `latest` stays on 0.8.1.

`CHANGELOG.md` gets a `v0.9.0-beta.1` section listing the 44 PRs merged
since v0.8.1, plus the two new contributors. This also drops the old
"Unreleased" section: its three entries (#424, #530, #531) already
shipped in v0.7.0.

Once this is merged, tag the merge commit `v0.9.0-beta.1` and push the
tag.

🤖 Written by [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>