{% include "server/head.html" %}
{% block head %}{% endblock %}
{# every request says the viewer's zone, and which build drew the page: one
left open across an upgrade is asked to refresh rather than patched with
pieces of the new build; the update bus goes by the server's own build #}
{# the page's own top bar: a way back on a narrow screen, its title, crumbs on a wide one, and its actions #}
{# the address back is a block of its own, read by the top bar and drawn nowhere else #}
{% if false %}{% block back %}{% endblock %}{% endif %}
{% block top %}{% set back = self.back() | trim %}
{% if back %}{% include "server/icons/chevron-left.svg" %}{% endif %}