Serve the wasm and scripts gzip-compressed (packed at build time)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

nginx.conf

@@ -4,6 +4,13 @@ server {
     index index.html;
     # test build: always reload fresh files
     add_header Cache-Control "no-cache";
+    # compressed downloads: the big files are packed once at build time (*.gz, see Dockerfile),
+    # the rest on the fly (the wasm goes from about 8.8 MB to 2.6 MB)
+    gzip_static on;
+    gzip on;
+    gzip_types application/wasm application/javascript text/css application/json application/manifest+json image/svg+xml;
+    gzip_min_length 1024;
+    gzip_vary on;
     location / {
         try_files $uri $uri/ =404;
     }