remove preact and create setup wizard

apps/server/internal/httpserver/templates/account.gohtml

@@ -56,6 +56,18 @@
       <p class="form-status" data-admin-users-status></p>
     </section>
 
+    <section class="account-section" data-admin-settings-section hidden>
+      <h2>Registration</h2>
+      <form class="auth-form" data-admin-settings>
+        <label class="auth-choice">
+          <input type="checkbox" name="signupsEnabled" />
+          Allow visitors to create accounts
+        </label>
+        <button type="submit">Save registration setting</button>
+        <p class="form-status" data-admin-settings-status></p>
+      </form>
+    </section>
+
     <section class="account-section account-section--danger">
       <h2>Delete Account</h2>
       <form class="auth-form" data-account-delete>