fix(#72,#59): remove nginx /health stub — API endpoint proxies through correctly

services/web-ui/nginx.conf

@@ -88,13 +88,6 @@ server {
         add_header Cache-Control "no-cache, no-store, must-revalidate";
     }
 
-    # Health check endpoint
-    location /health {
-        access_log off;
-        return 200 "healthy\n";
-        add_header Content-Type text/plain;
-    }
-
     # Deny access to dotfiles
     location ~ /\. {
         deny all;