security: bind service ports to localhost only

Bind navidrome, n8n, immich, openclaw, gitea web ports to 127.0.0.1
to prevent direct LAN access bypassing Caddy/Authelia.

Tailscale userspace networking on Synology proxies through localhost,
so VPS Caddy access via Tailscale IP continues to work.

Gitea SSH port (2222) remains on all interfaces for external git push.

n8n/docker-compose.yml

@@ -4,7 +4,7 @@ services:
     container_name: n8n
     restart: unless-stopped
     ports:
-      - "5678:5678"
+      - "127.0.0.1:5678:5678"
     volumes:
       - ./data:/home/node/.n8n
     environment: