The issue is that the form is being submitted with its default browser behavior. Let me fix the handleSubmit to use a click handler on the button instead, and also add some console logging to debug:
I've fixed the login redirect issue. The problem was that the form's default behavior was interfering with the router.push(). I've changed it to use a simple button with an onClick handler that directly calls the redirect function. Now when you click "Sign In", you should be immediately redirected to the dashboard. Try it now!