chore: update release notes for UTMStack v11.1.5 and standardize utm_visualization field names

Author: mjabascal10

CHANGELOG.md

@@ -1,8 +1,7 @@
-# UTMStack 11.1.4 – Release Notes
+# UTMStack 11.1.5 – Release Notes
 
-The **UTMStack v11.1.4** update delivers important fixes and usability improvements to enhance stability and user experience.
+The **UTMStack v11.1.5** update delivers important fixes and usability improvements to enhance stability and user experience.
 
 ## Improvements & Fixes
-- Refined the styling of download links to improve clarity and accessibility.
-- Resolved a syntax error in the UTMStack installation command, ensuring smoother setup.
-- Corrected the display of pipeline card statuses and improved accuracy of event processing counts.
+- Standardized `utm_visualization` field names by replacing legacy O365 keys with new conventions.
+