style: Made by Galyaviev larger, clickable mailto, remove login footer

- Increase signature font: sidebar 18px, login 20px
- Wrap in <a href="mailto:ruslan@ipcom.su"> on all pages
- Remove wg.4mont.ru footer and divider from login page

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

gui/templates/base.html

@@ -32,7 +32,7 @@
         <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M9 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h4"/><polyline points="16 17 21 12 16 7"/><line x1="21" y1="12" x2="9" y2="12"/></svg>
         Выйти
       </a>
-      <div class="made-by">Made by Galyaviev</div>
+      <div class="made-by"><a href="mailto:ruslan@ipcom.su">Made by Galyaviev</a></div>
     </div>
   </aside>
   <div class="layout">