perf(site): gzip CSS, JS, SVG and fonts on the furtka.org nginx

Default nginx only gzips text/html, so the homepage HTML was the only
asset coming back compressed. The ~600 KB three.min.js bundle (and the
hashed CSS) were being shipped uncompressed across the public openresty
proxy. `gzip_types` now covers css/js/json/xml/svg/woff2.

Needs `sudo ops/nginx/setup-vm.sh` on forge-runner-01 to take effect —
the site-deploy workflow only rebuilds Hugo, it doesn't touch the
nginx config.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

ops/nginx/furtka.org.conf

@@ -8,6 +8,23 @@ server {
 
     charset utf-8;
 
+    gzip on;
+    gzip_vary on;
+    gzip_min_length 1024;
+    gzip_comp_level 6;
+    gzip_types
+        text/css
+        text/plain
+        text/xml
+        application/javascript
+        application/json
+        application/xml
+        application/rss+xml
+        application/atom+xml
+        image/svg+xml
+        font/woff
+        font/woff2;
+
     location / {
         try_files $uri $uri/ $uri.html =404;
     }