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

docs/netbird-zero-trust.md

@@ -1,5 +1,5 @@
 <!-- verified: 2026-09-19
-     netbird-lxc@13b5d80 : netbird/Caddyfile, netbird/docker-compose.yaml, netbird/config.yaml.ctmpl
+     netbird-lxc@ea8967e : netbird/conf/Caddyfile, netbird/docker-compose.yaml, netbird/config.yaml.ctmpl
      iac@f770e1c : ansible/roles/secure_vault/netbird_agent, terraform/containers.tf
      trilium : qWLU4xqYLdJ3, oYuIjaczDrZA, nAPJq9A1iuX8, Cl4TWBZ7ytYr
 -->
@@ -56,9 +56,10 @@ The real path a request takes:
 And this is the actual splitter doing that work — the real config, not a description of the logic:
 
 ```
-$ cat Caddyfile
+$ cat conf/Caddyfile
 {
-	admin off
+	# Container loopback only (port not published) - `caddy reload` needs it.
+	admin localhost:2019
 	auto_https off
 	servers {
 		protocols h1 h2 h2c