Bump __version__ per ADR-007; roll Unreleased into the 0.6.0 changelog section. Covers the machines rename (ADR-011), the measuringtools plugin, per-plugin migrations (ADR-008), route gating (ADR-009), the get_reports hook (contract 0.6.0), and the sister-site adoption docs. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>