chore(release): prepare first beta (#7)

## Summary

- add the Tegami changelog for DomainKit's first public beta
- request a minor prerelease from the current `0.0.1` reservation

## Validation

- `bun run format:check`
- Tegami `version` followed by `publish --dry-run`
- full release gate passed: lint, typecheck, 66 source tests, build,
examples, and 6 packed-artifact tests
- predicted `domainkit@0.1.0-beta.0` on npm dist-tag `beta`

Merging this PR creates the separate Tegami version PR; it does not
publish the package.