nginx templates: the platform's /.well-known/security.txt (snippets/security-txt.conf) on every service vhost ovhost renders and on the Host dashboard; tenants' custom domains keep their own (WS-R task 7)

ddiff --git a/templates/nginx/tenants.conf.tmpl b/templates/nginx/tenants.conf.tmpl
iindex fe3aec9..cf30e07 100644
---- a/templates/nginx/tenants.conf.tmpl
++++ b/templates/nginx/tenants.conf.tmpl
@@@ -28,6 +28,7 @@ server {
      listen [::]:443 ssl;
      http2 on;
      server_name {{dashboard}};
++    include snippets/security-txt.conf;   # /.well-known/security.txt (the host's file; WS-R task 7)
  
      ssl_certificate     {{certDir}}/fullchain.pem;
      ssl_certificate_key {{certDir}}/privkey.pem;
ddiff --git a/templates/nginx/vhost.conf.tmpl b/templates/nginx/vhost.conf.tmpl
iindex ac27483..cdffeb5 100644
---- a/templates/nginx/vhost.conf.tmpl
++++ b/templates/nginx/vhost.conf.tmpl
@@@ -25,6 +25,7 @@ server {
      listen [::]:443 ssl;
      http2 on;
      server_name {{serverNames}};
++    include snippets/security-txt.conf;   # /.well-known/security.txt (the host's file; WS-R task 7)
  
      ssl_certificate     /etc/letsencrypt/live/{{certName}}/fullchain.pem;
      ssl_certificate_key /etc/letsencrypt/live/{{certName}}/privkey.pem;