docs(changelog): cut 0.9.0 — conditional HTTP helpers

CleanRequestInput (fused TrimStrings + ConvertEmptyStringsToNull),
CompiledPatternSet (array-aware amortised matcher), and a greased
Request::is(). All byte-identical; situational drop-ins documented off
the main tier menu as "Conditional Helpers".

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: serpentblade

CHANGELOG.md

@@ -6,6 +6,8 @@ All notable changes to `grease` are documented here. The format is based on
 
 ## [Unreleased]
 
+## [0.9.0] - 2026-06-27
+
 ### Added
 
 - **Conditional helpers — situational drop-ins for the HTTP request path, documented off the main
@@ -565,7 +567,8 @@ dirty-check.
 - PHP 8.2+
 - Laravel 12 / 13
 
-[Unreleased]: https://github.com/One-Learning-Community/grease/compare/v0.8.0...HEAD
+[Unreleased]: https://github.com/One-Learning-Community/grease/compare/v0.9.0...HEAD
+[0.9.0]: https://github.com/One-Learning-Community/grease/compare/v0.8.0...v0.9.0
 [0.8.0]: https://github.com/One-Learning-Community/grease/compare/v0.7.0...v0.8.0
 [0.7.0]: https://github.com/One-Learning-Community/grease/compare/v0.6.1...v0.7.0
 [0.6.1]: https://github.com/One-Learning-Community/grease/compare/v0.6.0...v0.6.1