fix: use start-stop-daemon for autossh background launch + add close button

- Replace setsid/nohup with start-stop-daemon -S -b as primary daemon
  method (setsid fails silently when script runs inside curl|sh pipe)
- Same fix in init.d S99hydra_tun start/restart cases
- Add "✓ Готово" button to tunnel modal to close it after setup

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

server/templates/index.html

@@ -232,6 +232,7 @@ input[type=text]:focus,input[type=password]:focus{border-color:var(--accent)}
     </div>
     <div style="display:flex;gap:8px;flex-wrap:wrap;align-items:center">
       <button class="btn btn-b" onclick="checkTunnelStatus()" style="font-size:12px">⟳ Проверить связь</button>
+      <button class="btn" onclick="closeTunnel()" style="font-size:12px;background:var(--green);color:#fff">✓ Готово</button>
       <span id="tun-status" style="font-size:12px;color:var(--muted)"></span>
     </div>
     <div style="margin-top:14px;font-size:11px;color:var(--muted)">