Prepare release v2.2.1 (#426)

- Update version to 2.2.1
- Document bug fixes in CHANGELOG

Author: Mat001

CHANGELOG.MD

@@ -4,12 +4,19 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [2.2.1] - October 24, 2025
+
+### Bug Fixes
+- **CMAB Cache Size Alignment**: Increased CMAB default cache size from 1000 to 10000 to align with ODP segments cache size for consistency ([#425](https://github.com/optimizely/go-sdk/pull/425))
+- **Bucketing Precision**: Fixed float32 precision error that caused incorrect bucketing for specific users ([#423](https://github.com/optimizely/go-sdk/pull/423))
+- **EU Region Support**: Fixed region parameter handling for EU data hosting ([#421](https://github.com/optimizely/go-sdk/pull/421))
+
 ## [2.2.0] - September 30, 2025
- 
+
   ### New Features
   - **CMAB (Contextual Multi-Armed Bandit) Support**: Added support for CMAB experiments with new configuration options and cache control ([#399](https://github.com/optimizely/go-sdk/pull/399), [#401](https://github.com/optimizely/go-sdk/pull/401), [#402](https://github.com/optimizely/go-sdk/pull/402), [#403](https://github.com/optimizely/go-sdk/pull/403), [#408](https://github.com/optimizely/go-sdk/pull/408), [#409](https://github.com/optimizely/go-sdk/pull/409), [#411](https://github.com/optimizely/go-sdk/pull/411), [#412](https://github.com/optimizely/go-sdk/pull/412), [#416](https://github.com/optimizely/go-sdk/pull/416))
   - **Multi-Region Support for Data Hosting**: Added SDK support for multi-region data hosting ([#414](https://github.com/optimizely/go-sdk/pull/414))
- 
+
   ### API Changes
   - **Client Factory**: `WithCmabConfig(*CmabConfig) OptionFunc` - New option for CMAB configuration ([#412](https://github.com/optimizely/go-sdk/pull/412), [#419](https://github.com/optimizely/go-sdk/pull/419))
   - **New Decide Options**: `IgnoreCMABCache`, `ResetCMABCache`, `InvalidateUserCMABCache` for CMAB cache control ([#401](https://github.com/optimizely/go-sdk/pull/401))

pkg/event/version.go

@@ -18,7 +18,7 @@
 package event
 
 // Version is the current version of the client
-var Version = "2.1.0"
+var Version = "2.2.1"
 
 // ClientName is the name of the client
 var ClientName = "go-sdk"