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-locations.inc

@@ -0,0 +1,84 @@
+# Shared SPA locations. Browser calls same-origin /api/ + /uploads/ (VITE_API_URL empty).
+# Nginx proxies internally to ark-library-backend-1 (Tailscale); Host header for backend TLS.
+gzip on;
+gzip_vary on;
+gzip_proxied any;
+gzip_comp_level 5;
+gzip_types text/plain text/css application/javascript application/json application/xml image/svg+xml;
+gzip_min_length 256;
+
+location ^~ /api/admin {
+  return 404;
+}
+location ^~ /admin {
+  return 404;
+}
+
+location ^~ /api/ {
+  proxy_pass https://100.93.205.19/api/;
+  proxy_http_version 1.1;
+  proxy_ssl_server_name on;
+  proxy_set_header Host api.ark-library.com;
+  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;
+  client_max_body_size 512m;
+  client_body_timeout 600s;
+  proxy_read_timeout 600s;
+  proxy_send_timeout 600s;
+}
+
+location ^~ /uploads/ {
+  proxy_pass https://100.93.205.19/uploads/;
+  proxy_http_version 1.1;
+  proxy_ssl_server_name on;
+  proxy_set_header Host api.ark-library.com;
+  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;
+}
+
+location = /health {
+  default_type text/plain;
+  return 200 "ok\n";
+}
+
+location = /healthz {
+  default_type text/plain;
+  return 200 "ok\n";
+}
+
+location = /index.html {
+  try_files $uri =404;
+  add_header Cache-Control "no-cache, no-store, must-revalidate" always;
+}
+
+# Exact `/` so the HTML shell is never edge-cached without validators (avoids stale index.html → 404 on hashed /index-*.js or /assets/*).
+location = / {
+  try_files /index.html =404;
+  add_header Cache-Control "no-cache, no-store, must-revalidate" always;
+}
+
+location = /assets/logo-primary.webp {
+  try_files $uri =404;
+  add_header Cache-Control "public, max-age=3600, stale-while-revalidate=86400" always;
+}
+location ^~ /assets/ark-library/ {
+  try_files $uri =404;
+  add_header Cache-Control "public, max-age=86400, stale-while-revalidate=604800" always;
+}
+
+location ^~ /assets/ {
+  try_files $uri =404;
+  add_header Cache-Control "public, max-age=31536000, immutable" always;
+}
+
+# Hashed entry chunk at /index-[hash].js (Vite entryFileNames). Do not 308 to /assets — file lives here.
+location ~* ^/index-[A-Za-z0-9_-]+\.(js|mjs)$ {
+  try_files $uri =404;
+  add_header Cache-Control "public, max-age=31536000, immutable" always;
+}
+
+location / {
+  try_files $uri $uri/ /index.html;
+}