Version bump for Child+1 feature + nested-semi-join fix. Updated
README "what's shipped" and limitations section: removed the two
items that 0.2.0 resolves (children's parents not walked, semi-join
in WHERE), added the new Child+1 feature description and its
scope caveat (one hop, user-selected).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>