my $resp = $app->($_[0]);
my $hdrs = Plack::Util::headers($resp->[1]);
$hdrs->set('Content-Security-Policy', CONTENT_SECURITY_POLICY);
- $hdrs->set('Link', '</static/slate.css>; rel=stylesheet') if $hdrs->get('Content-Type') =~ m,^text/html,;
$resp->[1] = $hdrs->headers;
$resp;
}