frontend: add management pages

core/frontend/widgets/err_banner.jinja

@@ -7,6 +7,10 @@ Card not registered, or wrong password
 Missing or malformed access code
 {% elif error == 3 %}
 Failed to create user
+{% elif error == 4 %}
+Arcade not found
+{% elif error == 5 %}
+Machine not found
 {% else %}
 An unknown error occoured
 {% endif %}

core/frontend/widgets/topbar.jinja

@@ -9,6 +9,9 @@
 </div>
 </div>
 <div style="background: #333; color: #f9f9f9; width: 10%; height: 50px; line-height: 50px; text-align: center; float: left;">
+    {% if sesh is defined and sesh["permissions"] >= 2 %}
+    <a href="/sys"><button class="btn btn-primary">System</button></a>
+    {% endif %}
     {% if sesh is defined and sesh["userId"] > 0 %}
     <a href="/user"><button class="btn btn-primary">Account</button></a>
     {% else %}