feat: restrict AdGuard Home, Backrest, and qBittorrent to internal network

conf.d/qbittorrent.conf.template

@@ -5,6 +5,7 @@ server {
     server_name qbt.${BASE_DOMAIN};
 
     include snippets/proxy.conf;
+    include snippets/internal-only.conf;
 
     location / {
         proxy_pass http://qbittorrent:8080;