Remove repeated demo notes from product screens (#28)

frontend/app/lib/auth/form.dart

@@ -133,11 +133,6 @@ class _AuthFormState extends State<AuthForm> {
             ),
           ),
         ),
-        const SizedBox(height: 16),
-        Text(
-          l.earlyPreview,
-          style: text.bodySmall!.copyWith(color: colors.onSurfaceVariant),
-        ),
         const SizedBox(height: 24),
         Text(
           _signUp ? l.signupHeading : l.loginHeading,