n8n: add workflow automation at n8n.hidrago.click

- Docker Compose (port 5678)
- nginx reverse proxy + SSL Let's Encrypt
- systemd user service (n8n.service)
- HTTPS accessible on https://n8n.hidrago.click

vault.hidrago.click.nginx

@@ -3,6 +3,17 @@ server {
 
     client_max_body_size 128M;
 
+    # Cache static assets (admin panel icons, CSS, JS)
+    location /vw_static/ {
+        proxy_pass http://127.0.0.1:8081;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+        expires 7d;
+        add_header Cache-Control "public, immutable";
+    }
+
     location /notifications/hub {
         proxy_pass http://127.0.0.1:3012;
         proxy_http_version 1.1;