Message archiving to be enabled by default

The Monitoring plugin provides multiple features, but its primary and most widely used functionality is message archiving. Currently, message archiving is disabled by default, requiring administrators to manually enable it after installing the plugin. This leads to several problems: - Administrators often assume archiving works immediately after plugin installation. - Deployments relying on historical message retention may unintentionally run without archiving for long periods. - The plugin’s main purpose is not fully realized out-of-the-box. Please update the plugin so that Message Archiving is enabled by default upon installation. This change would make the plugin’s key functionality immediately available, reduce common configuration errors, and better align default behavior with user expectations.