Terminate Session Automatically When Browser Tab Is Closed

NetBrain currently does not end a user session when the browser tab is closed; the session remains active until it separately times out. This means that reopening a stale tab or URL can present a confusing state rather than a normal login prompt. This enhancement would terminate the session automatically when the browser tab is closed, so that a later reopen leads directly to a clean login screen. Customers would benefit from clearer session behavior and reduced confusion when returning to the application after closing a tab.