feat(header.html): add header template

src/judas_server/web/templates/base/header.html

@@ -0,0 +1,13 @@
+<header class="flex items-center justify-between px-4 py-2 bg-ctp-crust">
+  <h2 class="text-2xl font-bold font-mono text-ctp-blue"><a href="{{ url_for('index.index') }}">judas</a></h2>
+  <p id="no-connection-message" class="flex align-center justify-center gap-2 text-ctp-red">
+    <i class="fi fi-rr-link-slash text-xl"></i>
+    <span> No connection to server </span>
+  </p>
+
+  {% if current_user.is_authenticated %}
+  <a class="btn-primary" href="{{ url_for('auth.logout') }}">Logout</a>
+  {% else %}
+  <a class="button" href="{{ url_for('auth.login') }}">Login</a>
+  {% endif %}
+</header>