Same-origin API: empty VITE_API_URL with nginx proxy to backend-1.

Frontends call /api/ on ark-library.com; nginx forwards internally to 100.93.205.19.

Co-authored-by: Cursor <cursoragent@cursor.com>

deploy/nginx-frontend-native.conf

@@ -0,0 +1,18 @@
+# Native system nginx (not Docker). SPA root: /var/www/ark-library
+# Snippet: /etc/nginx/snippets/ark-library-frontend.inc
+# ALB terminates TLS; apex uses X-Forwarded-Proto so we do not 301-loop behind the LB.
+
+server {
+  listen 80 default_server;
+  listen [::]:80 default_server;
+  server_name ark-library.com www.ark-library.com;
+
+  if ($http_x_forwarded_proto != "https") {
+    return 301 https://$host$request_uri;
+  }
+
+  root /var/www/ark-library;
+  index index.html;
+
+  include /etc/nginx/snippets/ark-library-frontend.inc;
+}