Update changelog

Signed-off-by: Chris PC <chrispc@li-4dc2bf4c-325d-11b2-a85c-b68e8b1fc307.ibm.com>

Author: Chris PC

charts/mcp-stack/CHANGELOG.md

@@ -6,6 +6,17 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/)
 
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+## [0.9.1] - 2025-12-03
+
+### Added
+* **Helm Hook Support for Migration Job** - : enable recreation of the migration Job on every deployment
+  - helm.sh/hook: pre-install,pre-upgrade — ensures the migration Job runs automatically during installs and upgrades
+  - helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded — removes old migration Jobs to prevent immutable field errors
+  - Eliminates upgrade failures caused by changes to spec.template in Kubernetes Jobs
+
+### Changed
+* **Chart version** - Bumped to 0.9.1 for migration job fix
+
 ## [0.9.0] - 2025-11-05
 
 ### Added