v0.6.0 — Interactive watch mode + pipeline fix

- bam -w <task> now restarts interactive (server) tasks automatically on input change
- Fix GitLab CI open-schemastore-pr YAML parse error (unquoted colon in commit message)
- Fix wait_for_change observer.join blocking on cancellation (timeout=2.0)
- 213 tests passing

See CHANGELOG.md for the full list of changes.