Merge pull request #78 from koriym/release-prep-v0.9.0

chore: release v0.9.0

Author: koriym

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.9.0] - 2026-04-30
+
 ### Added
 - **xstep JSON ergonomics** (#74):
   - `--pretty` for indented JSON output