Add pre-test stage reset to ensure known environment state

- Add reset_stage_pre job that runs after deploy_stage but before integration tests
- Extract reset script into reusable .reset_stage_template
- Ensures stage environment is in known state even if manually modified
- Pipeline flow: deploy_stage → reset_stage_pre → integration_test_stage → reset_stage

CHANGELOG.md

@@ -7,11 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 ### Changed
-- Added pre-test stage reset to ensure known environment state before integration tests (#54)
-
-## [0.5.1] - 2026-01-23
-### Changed
 - Simplified tag pipeline to only run deploy and smoke tests (image already built on main) (#54)
+- Added pre-test stage reset to ensure known environment state before integration tests (#54)
 
 ### Fixed
 - Fixed production CI deployment namespace to use correct `orch-namespace` (#54)