Release version 6.0.0

This major release includes:
- ⚠️ [Breaking] Remove `ApiVersion::LATEST` constant to prevent semver violations
- Add compliance webhook topics (#425)
- Add support for 2025-10 API version (#433)

The `apiVersion` parameter is now required in `Context::initialize()`.
Developers must explicitly specify API versions.
See BREAKING_CHANGES_FOR_V6.md for migration details.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: lizkenyon

CHANGELOG.md

@@ -6,6 +6,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## Unreleased
+
+## v6.0.0 - 2025-10-28
 - ⚠️ [Breaking] Remove `ApiVersion::LATEST` constant to prevent semver violations. The `apiVersion` parameter is now required in `Context::initialize()`. Developers must explicitly specify API versions. See the [migration guide](BREAKING_CHANGES_FOR_V6.md#removal-of-apiversionlatest-constant) for details.
 - [#425](https://github.com/Shopify/shopify-api-php/pull/425) [Patch] Add compliance webhook topics
 - [#433](https://github.com/Shopify/shopify-api-php/pull/433) [Minor] Add support for 2025-10 API version

src/version.php

@@ -1,5 +1,5 @@
 <?php
 
 // @codeCoverageIgnoreStart
-return '5.11.0';
+return '6.0.0';
 // @codeCoverageIgnoreEnd