docs, stacks: Caddyfiles moved to a folder mount (conf/Caddyfile)

docs/sso-and-identity.md

@@ -1,6 +1,6 @@
 <!-- verified: 2026-09-18
-     rocky-docker-lxc@7dd5025 : caddy/Caddyfile
-     caddy-vm@9369f8b : caddy/Caddyfile
+     rocky-docker-lxc@d225776 : caddy/conf/Caddyfile
+     caddy-vm@c5c3420 : caddy/conf/Caddyfile
      iac@f770e1c : ansible/roles/bootstrap_roles/docker_git_setup
      trilium : baWhWTUejvY6, hWiIGZIlvQiN, nAPJq9A1iuX8
 -->